This installment of "Column Watch" is intended to cover chromatography columns and accessories commercially released after Pittcon 2017 through this year's conference held in Orlando, Florida. LCGC once again sent out a survey in early 2018 asking vendors to supply them with any products launched after Pittcon 2017. Other areas such as gas chromatography (GC), instrumentation, and sample preparation are covered elsewhere. Because information for this article is obtained sporadically over the course of many months, it is very possible that some information has been missed. The reader is encouraged to check with specific vendor sites for additional products as well as more detailed information regarding what is covered here.

	The vendors that responded to the survey with high performance liquid chromatography (HPLC) and ultrahigh-pressure liquid chromatography (UHPLC) columns are listed in Table I. The product range is highly varied from traditional reversed-phase columns using fully porous materials to columns designed for alternate separation technologies such as supercritical fluid chromatography (SFC). The present discussion is organized around several classes of liquid chromatography (LC) columns. Small-molecule reversed-phase columns, hydrophilic-interaction chromatography (HILIC) columns, and chiral columns continue to surface and are thus discussed separately. Columns intended for reversed-phase analysis of large molecules including proteins, peptides, and amino acids make up another separate category. Alternative modes of chromatography for both small and large molecules such as ion-exchange, size-exclusion or gel permeation, and supercritical fluid chromatography are also discussed individually. Finally, new developments in nano- and microseparations are presented. Trends noted throughout the article are based on comparisons to 2016 (1) and 2017 (2) reports.

	The product offerings assigned to the small-molecule reversed-phase category are listed in Table II. A total of 18 new column options, including existing particle and chemistry combinations packed in alternative hardware designs are shown. Continuing with recent trends, many of the new columns are intended to round out selectivity or particle size offerings within existing lines. Of the 18 columns listed, nine are manufactured using superficially porous particles (SPPs), indicating that the particle architecture continues to garner attention. Agilent Technologies expanded its InfinityLab Poroshell 120 line by applying existing surface chemistries to a 1.9-µm (SPP) particle size. Two specialty columns based on SPP technology are also noted. Phenomenex reported the release of the Kinetex 3.5 PAH column, which uses a polymerically bonded C18 on the company's SPP platform for highly efficient separation of polyaromatic hydrocarbons. Restek released an EtG/EtS (ethylglucuronide/ethylsulfate) column based on a proprietary bonding. This SPP-based column is reported to provide stronger retention for these polar compounds, enabling consistent resolution from matrix interferences. Another notable trend from 2017 that continued in 2018 is the constant expansion of C18 technologies to retain a wider range of compounds or to provide alternative selectivity to classic C18 chemistry. Advanced Materials Technology released the Halo 90Å AQ-C18 column based on the company's 2.7-µm SPP platform. The polar modification enables 100% aqueous mobile phases to be used without loss of retention because of so-called dewetting. Similarly, Macherey-Nagel released an SPP C18 with polar endcapping that reportedly provides enhanced retention for hydrophilic compounds. Lastly, Nomura Chemical Company launched Develosil HSR AQ C18. The column is described as exhibiting a proprietary C18 chemistry that provides retention for polar compounds as an alternative to using HILIC. Imtakt Corporation released one additional C18 chemistry. The Dacapo DX-C18 column was not described as a "polar" or "aqueous" C18; however, the company claims improved peak shapes for basic compounds as well as extended pH capabilities. ES Industries added an additional diphenyl bonded chemistry to its Epic line, noting enhanced π-π interactions exhibited by this phase that are useful for the separation of aromatic isomers. YMC released its YMC Triart line based on hybridized silica in new PEEK-lined hardware. The company claims the hardware design is useful for analysis of coordination compounds that can interact with stainless steel columns and frits.

Hydrophilic-Interaction Chromatography Columns

	HILIC, which is often used for the retention and separation of highly polar compounds, continues to show steady growth. Table III lists product offerings in the HILIC category. The seven new entries match the number of new columns reported in both 2017 and 2016. It is interesting to note that new HILIC columns based on polymeric, SPP, and sub-2-µm supports were released. Advanced Chromatography Technologies launched a series of phases under its ACE brand of fully porous particles (FPP). The ACE-HILIC-A, ACE HILIC-B, and ACE HILIC-N columns are intended to cover a wide range of polar analytes. The company provides the columns in a kit and has developed systematic method development scenarios to support users. Agilent Technologies expanded its InfinityLab Poroshell 120 HILIC SPP-based offering by launching a polyhydroxyl cyclofructan (HILIC-OH5) and a proprietary zwitterionic chemistry (HILIC-Z). Both phases are reported to provide alternative selectivity to existing HILIC phases, thus expanding options for the end user. HILICON AB introduced iHILIC(+)-Fusion on a 1.8-µm FPP support, also claiming unique selectivity from a variety of potential molecular interactions. The lone polymeric entry was from Shodex. The company's VN-50 4D column is a polyvinyl alcohol support with diol functional groups. The company reports that the column is suitable for oligosaccharide separations, among others.

	Interest in the development of chiral phases was apparent over the past year as 14 new phases were introduced since Pittcon 2017 (See Table IV). Agilent Technologies and AZYP LLC both introduced a number of brush-type phases based on SPP platforms. Both companies launched stationary phases that include modified cyclodextrin, cyclofructan, and several macrocyclic glycopeptides. The SPP technology is reported to provide increased efficiency and speed as compared to classic fully porous columns with similar chemical modifications. Regis Technologies applied sub-2-µm particle technology to its well-known Whelk-O 1 line of columns, which are designed to provide very high efficiency and resolution. Immobilized amylose and cellulose phases continue to be developed. Chiral Technologies introduced Chiralpak IH with an amylose tris(

)-α-methylbenzylcarbamate support, claiming increased loadability and robustness over coated polysaccharide phases. Phenomenex added to its Lux family of chiral phases with an immobilized amylose tris(3,5-dimethylphenylcarbamate) phase. An immobilized cellulose tris(4-methylbenzoate) phase was introduced by YMC, who noted that the phase provides a wide pH range and is the first of its kind to the market. ES Industries also expanded its ChromegaChiral line with a 4-fluoro-3-(trifluoromethyl)phenylcellulose phase that reportedly provides enhanced chiral separation of halogenated enantiomers.

	New developments intended for reversed-phase analysis of large molecules have continued to reach the market over the past year. New columns introduced for reversed-phase chromatography of proteins, peptides, amino acids, and other biomolecules are presented in Table V. It is apparent from the list that peptide analysis was a clear target for column vendors. Advanced Materials Technologies introduced a 160-Å phenyl-hexyl column based on its SPP technology that provides unique selectivity as compared to other phase chemistries within the company's platform. Agilent Technologies introduced AdvanceBio Plus, described as a hybrid endcapped C18, that also takes advantage of SPP architecture. Agilent also introduced AdvanceBio Amino Acid and AdvanceBio MS Spent Media columns. The former column reportedly provides sensitive and reproducible separation of amino acids in protein hydrosylates and cell culture media, whereas the latter column is intended for bioreactor cell culture media analysis. Nomura Chemical launched Develosil HSR C18 Peptide columns, noting durability of its new proprietary bonding technology. Shodex introduced LW-803, a 1000-Å conventional porous silica that they claim is ideal for antibody and protein analysis. Lastly, Waters introduced several new phases aimed at large-molecule separations. XBridge Peptide BEH C18 is noted as providing greater temperature and pH stability because of their hybrid silica technology as compared to silica-based column designs. The Acquity UPLC and XSelect Peptide HSS T3 columns are based on fully porous particles ranging in size from 1.8 µm to 5 µm and are reported to provide increased retentivity as compared to the company's hybrid-based phases. Finally, Waters also introduced BioResolve RP mAb Polyphenyl, which is a 450-Å SPP-based column intended for separation of monoclonal antibodies (mAbs) and antibody–drug conjugates (ADCs).

Size-Exclusion Chromatography and Gel Permeation Chromatography

	Offerings for size-exclusion chromatography (SEC) and gel permeation chromatography (GPC) continue to be developed. For a brief introduction to the techniques, please see reference 2. Two new columns were launched over the past year. Agilent Technologies released InfinityLab PL Multisolvent columns. According to the company, the new high-resolution GPC–SEC columns for polymer analyses offer high resolution in both aqueous and organic solvent systems. The columns are based on a 2.7-µm particle offered in both 120-Å and 300-Å pore sizes. These unique silica-based columns offer wide solvent compatibility that translates to significantly improved run times and resolution when measuring low- and mid-range MW polymers. Imtakt Corporation introduced Intrada SEC for size-exclusion chromatography. The 300-Å, 3-µm substituted diol chemistry was developed for mass spectrometry (MS)-compatible SEC. The company reports reduced secondary interactions and high pH stability, making the columns applicable to biological or synthetic polymers, IgGs, ADCs, and mAbs.

	Ion-exchange chromatography exploits strong interactions between opposite charges of a surface and an analyte. Polymeric supports are often modified to carry permanent (strong cation–anion exchange) or variable (weak cation–anion exchange) charge that can be used to interact with and separate analytes with the opposite charge. Ion-exchange chromatography is a complementary tool for the analysis of large molecules, but is also used for the analysis of small anions and cations. Shodex introduced two new ion-exchange chromatography columns during the past year, SP-FT 4A and VC-50 2D. The SP-FT 4A column is described as a nonporous polyhydroxymethacrylate support with sulfopropyl functional groups. The company notes that the columns provide ultrarapid protein analysis using conventional HPLC systems. The VC-50 2D column is based on a 5-µm, 100-Å polyvinyl alcohol support with carboxyl functional groups. The modified carboxyl group is suitable for cationic samples, including amines. The dominant separation mode is noted as reversed-phase or ion-exchange chromatography, and the column is reported to be useful for oligonucleotides, hydrolyzed dextran, and oligosaccharides. Thermo Fisher Scientific introduced several new phases: the IonPac AS16-4µm anion-exchange column, the IonPac AS29-Fast-4µm anion-exchange column, the CarboPac PA20-Fast-4µm carbohydrate column, and the IonPac CS20 cation-exchange column. The IonPac AS16-4µm anion-exchange column is designed for the analysis of trace perchlorate and other highly polarizable anions in a variety of sample matrices. The AS29-Fast-4µm column is intended for fast isocratic separation of inorganic anions. The CarboPac PA20-Fast-4µm carbohydrate column is designed for fast separation of mono- and disaccharides in pharmaceutical and food and beverage matrices. According to the company, the new 4-µm analytical columns offer superior performance for isocratic separation with improved peak efficiency, peak symmetry, retention time, ruggedness, and durability. The IonPac CS20 cation-exchange column is a combination of sulfonic, phosphonic, and carboxylic groups that is designed to provide superior performance for the determination of inorganic cations and amines.

	Supercritical fluid chromatography (SFC) continues to receive interest because of improvements in instrument design, the desire to perform greener separations, and due to the high resolution and speed the technique often provides. ES Industries introduced GreenSep Napthyl, a high-density naphthalene modification, intended for the SFC separation of hydrophobic molecules. ES Industries reports enhanced retention and separation of hydrophobic molecules and application toward natural products, PAHs, and steroids. Regis Technologies released the Celeris Achiral SFC line of columns. Celeris is a family of achiral stationary phases specifically designed for SFC separations that are intended to deliver high capacity, broad selectivity, excellent peak shapes, and reproducible performance over long column lifetimes. Several stationary phase modifications are available, including 2-ethylpyridine, 4-ethylpyridine, PEI, arginine, and amino modifications.

	During Pittcon 2017, PharmaFluidics launched the first microchip chromatography device manufactured using lithographic techniques. The device featured a perfectly ordered backbone that is formed by etching interstitial volume out of a silicon wafer. Since that introduction, PharmaFluidics has released the µPAC trapping column to enable fast sample cleanup and enrichment of samples before injection onto the company's analytical columns. The company reports that, similar to the analytical columns, the µPAC trapping columns are unique in that they consist of a perfectly ordered array of micropillars that have been etched out of a solid piece of silicon. The column dimensions have however been redesigned to allow higher flow rates. These high flow rates are essential for reducing sample loading times to a minimum. Whereas analytical µPAC analytical columns can be operated within a flow rate range of 0.1–2.5 µL/min, the trapping column can easily be operated at flow rates up to 50 µL/min, thereby reducing sample loading time by an order of magnitude.

	Waters Corporation introduced nano-Ease M/Z columns based on fully porous sub-2-µm, 100-Å (silica), 130-Å, and 300-Å (hybrid) particles with C18 and C4 modifications. The columns are available in 75–150 µm internal diameters and 50–250 mm lengths. Intended for peptide mapping and peptide–protein quantification, these columns are reported to be easy-to-use with fingertight high-pressure fluid connections and increased chromatographic reproducibility. Waters Corporation also released the iKey HT (high throughput) separation device based on a sub-2-µm, C18 platform (100 Å [silica] and 130 Å [hybrid]) for peptide quantification. According to the company, the 300-µm i.d. iKey HT enables greatly reduced cycle times for microflow LC–MS analysis with the sensitivity benefit of microflow LC–MS. The ionKey/MS system integrates the microscale separation into the source of a mass spectrometer, dramatically enhancing the sensitivity for quantitative and qualitative LC–MS analyses. The 300-µm i.d. separation channel of the iKey HT reduces cycle time and enables increased sensitivity for laboratories requiring a higher level of sample throughput.

	Liquid chromatography column alternatives continue to be developed at a steady rate. The development of new stationary phases using modern particle designs such as superficially porous, sub-2-µm, and hybrid materials is most prevalent. Superficially porous columns, for example, are now available for chiral applications. The interest in HILIC as an alternative to reversed-phase LC continues to garner attention; however, expansion of reversed-phase capabilities is also a notable trend with several new "AQ" and "polar" C18 offerings now available. As in 2017, less attention has been paid to large-molecule separation tools in 2018 as compared to prior years. Even within this category, many of the columns were designed for peptides and amino acids rather than intact proteins. Techniques complementary to reversed-phase mode such as SEC–GPC and ion-exchange chromatography continue to grow at a steady pace. The commercialization of several micro- and nano-LC devices may be indicative of trends moving forward.

	Product reviews such as the present work would not be possible without the contributions and cooperation of the manufacturers that have responded to the 

 survey. Your effort is greatly appreciated. Although 

 has made every attempt to include every submission in the series of review articles, it is possible that some have been missed. If there have been omissions or if you want to be included in the 2019 review series, please contact Laura Bush, Editorial Director, 

is a director of Research and Development at Restek. He also serves on the Editorial Advisory Board for 

 and is the Editor for "Column Watch." Over the past 20 years, he has worked directly in the chromatography industry, focusing his efforts on the design, development, and application of chromatographic stationary phases to advance gas chromatography, liquid chromatography, and related hyphenated techniques. His undergraduate studies in chemistry were completed at the State University of New York at Plattsburgh (SUNY Plattsburgh). He received his PhD in analytical chemistry from The Pennsylvania State University and spent the first decade of his career in the pharmaceutical industry performing analytical method development and validation using various forms of chromatography and electrophoresis. His main objectives have been to create and promote novel LC technologies and to conduct research on molecular interactions that contribute to retention and selectivity in an array of chromatographic processes. His research results have been presented in symposia worldwide, and have resulted in numerous peer-reviewed journal and trade magazine articles. Direct correspondence to: 

Articles

Column Watch

Our annual review of new liquid chromatography columns and accessories, including columns for reversed-phase, HILIC, chiral, SEC, GPC, ion-exchange, and SFC separations of small and large molecules.

New Chromatography Columns and Accessories for 2018

Is that peak "pure"? How do I know if there might be something hiding under there?

	In part I of this series we discussed how the peak purity tools commonly provided in chromatographic data system software could aid in the detection of impurities in liquid chromatographic analysis (1). Here, we go one step further, and explore how a class of chemometric techniques known as 

 can be used to differentiate between a target compound and impurities, and subsequently quantify them, even when their peaks are overlapped.

	As in the previous installment (1), we focus on diode-array detection in liquid chromatography (LC–DAD). While mass spectrometric detection undoubtedly gives more selective information in the vast majority of cases, it is clearly a more complex detection mode and is prone to effects that can hamper quantitation such as ionization suppression because of matrix effects. The potential for highly precise quantitation of low-level impurities using DAD data is actually quite good, provided the spectra of the impurities have significantly different spectroscopic signatures as compared to the main peak. The latter point is of course an important caveat.

	Multivariate Curve Resolution-Alternating Least Squares

	In part I of this series we discussed the power of utilizing all of the absorbance information provided by a diode-array detector at multiple wavelengths to assess peak purity (1). Chemometric curve resolution techniques take this one step further. These techniques analyze the matrix of absorbance measurements at all wavelengths (that is, spectra) at all time points across a given time region of the chromatogram. Using a regression-based approach to determine how the spectra change over time, any impurities cannot only be discovered, but also be mathematically resolved from the target peak.

	Here we illustrate one of the most popular curve resolution techniques, known as 

multivariate curve resolution-alternating least squares

) (2–6). The basis for this technique is a multicomponent formulation of Beer's law given as

 represents the measured absorbance of a mixture solution at wavelength λ, 

 represent the molar absorptivities at this wavelength for two chemical species X and Y, and 

 represent the concentrations of these species in the solution. For a two-component mixture, if absorbance measurements are obtained at two different wavelengths, and the molar absorptivities are known, it is possible to solve for the concentrations of the two species, X and Y, in the mixture solution via simple algebra. If measurements at more than two wavelengths are available, least squares regression is needed to obtain the concentrations. It is important to note that the assumption that the two (or more) signals are linearly additive is only valid in cases where the total signal is within the linear range of the detector (for example, at signals less than about 1500 mAU with DAD).

	At this point, we generalize the discussion to a measurement 

, and consider this as a signal in an LC–DAD chromatogram, such that the variable 

th wavelength of the chromatogram. Additionally, we consider the possibility that more than two chemical species may be present in the sample within the chromatographic peak, which gives the following expression:

 refers to the molar absorptivity-pathlength product for species 

th wavelength. The full spectrochromatogram can be easily understood in terms of a matrix product. In matrix notation, equation 2 is commonly written as

 represent the absorbance at each wavelength and time point, respectively, and the superscript T refers to the matrix transpose. This concept is illustrated schematically in Figure 1. If the molar absorptivities are known at all measured wavelengths for all species present in the peak, then it is straightforward to solve for the resolved chromatograms, 

	where the superscript † indicates the pseudo inverse operation. Equation 4 is simply a linear regression equation in matrix format. The columns of 

 are the individual component chromatograms (that is, each compound plus any background contributions), and the rows of 


	Figure 1: Schematic for resolution of a spectrochromatogram represented by a matrix, X, into two component chromatograms and spectra contained by matrices C and S, respectively.

	While in theory this approach could be a means of resolving overlapped chromatographic peaks, if there are unknown impurities present or uncharacterized mobile phase background components or species, then we do not have enough information to specify the 

 matrix. The MCR-ALS technique then becomes quite useful in this regard. Rather than exactly specifying 

 is provided to the regression. This initial estimate can be obtained in a number of different ways. Pure variable methods are frequently used for this purpose. These methods seek to find the 

 most different spectra from the chromatographic data matrix, 

 is the number of components needed to describe the measured data. The principle is that the most different spectra in the matrix are likely to be similar to the underlying pure component spectra. The caveat is that the number of components must be set by the user. Methods have been proposed for selecting the correct number of components such as scree plots; however, the only reliable method is evaluation of the results for multiple values of 

. For a simple impurity screen, running MCR-ALS with two and three components to start should suffice, as one component would represent background, one would represent the target analyte, and if a third component is necessary, it is most likely because of an impurity peak.

 is obtained, equation 4 is used to solve for the chromatographic profile matrix, 

 will only be an approximation as well. MCR-ALS can be considered an optimization method in which these 

 matrices are continuously improved with the goal of accurately representing the true underlying chromatographic and spectral profiles of each component. The power of MCR-ALS lies in the judicious implementation of constraints on the 

 matrix as well) during this optimization. One frequently applied constraint is non-negativity, which allows the user to force the chromatographic profiles contained in 

 to have only positive values (6,7). Another constraint is unimodality, which forces each individual species chromatogram to exhibit a single peak (7). Many other constraints have been developed for MCR-ALS, but they are too numerous to describe here. Once 

 is constrained appropriately, the spectral matrix is updated via linear regression using equation 5:

	Now, constraints can be applied to this 

 matrix as well; non-negativity is frequently used in this case too. By updating the 

 matrices in an alternating fashion (that is, equations 4 and 5), interspersed with the application of constraints, the final solutions for 

 will contain the pure component profiles of the individual chemical species within the chromatographic peak.

	We illustrate this approach using the chromatographic peak that was analyzed in part I of this series (1). Figure 2a shows the chromatographic peak, and Figure 2b shows the contour plot of the matrix 

. We first applied a pure variable method (in this case the pure method in the Barcelona MCR-ALS toolbox, based on the SIMPLISMA algorithm [8–10]), and selected the three most different spectra within the spectrochromatogram. The corresponding time points are shown as circles in Figure 2a, and the three spectra at these points are shown in Figure 2c. It is likely that the spectrum shown in green represents a background spectrum, because it corresponds to a spectrum appearing in the baseline (green circle at 9.77 min in Figure 2a). After these initial estimate spectra are submitted to MCR-ALS, it should allow the algorithm to estimate the background contribution to the data, as well as the chromatographic peaks for each chemical species present within the profile.


	Figure 2: (a) Chromatogram of impure peak at 212 nm; (b) representation of this chromatogram as a contour plot where the y-axis is the UV-visible absorbance spectrum axis and the x-axis is the chromatographic time axis; (c) three most "pure" spectra within the spectrochromatogram found at the points circled in (a).

	The results for MCR-ALS analysis of this peak using these spectra for initial estimates are shown in Figure 3. Two peak shape responses within the chromatogram are resolved as shown in Figure 3a. These are two of the components contained in the matrix 

, corresponding to two chemical species (peaks shown in blue and red), and a background contribution from the mobile-phase gradient shown in green. The normalized spectra contained in matrix 

, which correspond to these species or contributions, are shown in Figure 3b. Note that the non-negativity constraint has been applied to the components corresponding to the real chemical species (shown in red and blue), while the background component (green) was not constrained. This flexible application of constraints leads to a powerful algorithm for curve resolution.


	Figure 3: MCR-ALS results from the chromatogram shown in Figure 1. (a) Resolved pure component chromatograms; (b) resolved pure component spectra. The red and blue curves represent chemical species and the green curves represent background contributions.

	A natural limitation of the MCR-ALS algorithm in this case is that there generally are multiple mathematical solutions that satisfy equation 3. Constraints are used to limit the possible solutions, but this generally does not provide a unique, chemically valid solution, especially when using MCR-ALS to analyze a single chromatogram, as described above. An extension of the MCR-ALS technique to analyze multiple chromatograms simultaneously is quite powerful in this regard, especially for quantitative analysis. In this approach, the analyst runs a series of calibration sample mixtures with varying concentrations of the target analytes, and obtains chromatograms for test samples with unknown concentrations of the target analytes. Because MCR-ALS resolves signals resulting from individual chemical species, these calibration solutes are not required to be individual standards and can, in fact, be mixtures of the compounds of interest, minimizing the number of calibration samples that need to be analyzed. These measured spectrochromatograms are appended together along the time axis to form an augmented matrix 

 unknown chromatograms. MCR-ALS is carried out similarly to the approach described above. The resulting 

 spectra of the pure component species, but the resulting 

 species, appended together similarly as shown in equation 6. The resolved chromatograms and spectra for a dataset of five calibration standards, C1–C5, and one unknown, U1, are shown in Figure 4 (that is, 

 = 1). The table above the figure shows the known concentrations of the standard mixtures, and it can be seen that the scaled peak intensities in the chromatograms (Figure 4a) are proportional to these concentrations. By integrating these resolved chromatographic peaks, calibration curves can be constructed, as shown in Figure 5.


	Figure 4: (a) Resolved chromatograms for five calibration mixtures (C1 through C5) containing psoralen and angelicin; table shows the corresponding concentrations; (b) Resolved spectra for psoralen (red), angelicin (blue) and a gradient background contribution (green). 

	A clear advantage to handling multiple chromatograms simultaneously is that calibration information and estimates of unknown concentrations can be obtained very efficiently. Another advantage is the potential to add additional constraints to the analysis, which further limits the possible solutions for 

. For example, if a blank chromatogram is included in the data set, the contributions of the chemical species for this chromatogram can be set to zero forcing the blank to be modeled using only the background components. Additionally, calibration constraints can be added to the analysis, which constrain the peak areas for the calibrated samples to follow an expected relationship between detector signal and concentration (11–13).


	Figure 5: Calibration curves for (a) psoralen and (b) angelicin from MCR-ALS results. Colored circles indicate calibration points; black squares denote unknown sample points.

	Of particular note here is the fact that two compounds present in the unknown sample have been reliably quantified, despite the resolution between the two peaks being significantly less than 1, and a high degree of similarity between their spectra. Here the chromatographic resolution of the two peaks is approximately 0.6.

	The performance of the MCR-ALS algorithm is highly dependent on the similarity of the spectra of the species contributing to the overlapped peak, as well as the signal-to-noise ratio (S/N) of the peaks. Here the similarity of the spectra for the two analytes psoralen and angelicin can be expressed by the correlation coefficient, which is 0.98 (see part I for further discussion).

	The improvement of effective chromatographic performance can be quantified in terms of the peak capacity of the separation. The peak capacity of a gradient separation, 

 is the average width of the peaks at the base. The 

' term is the resolution required for effective quantitative analysis (14). Typically, chromatographers use an 

' value of 1 when calculating peak capacity. Clearly, if peaks can be quantified at a resolution of less than 1 using curve resolution as discussed above, then the effective peak capacity has been increased. In recent work, we have developed a quantitative relationship between peak capacity and the signal-to-noise ratio of neighboring peaks and spectral similarity as measured by correlation coefficient. As an example, if the correlation coefficient between the overlapped spectra is 0.89 and S/N is 50, the chromatographic resolution required for quantitation is 

' = 0.3. This results in a roughly threefold improvement in peak capacity relative to conventional use of DAD where the only means of separation is that provided by the column itself. Clearly, MCR-ALS can provide a significant enhancement in chromatographic method performance.

	Availability of MCR-ALS in Software Packages

	One hurdle to widespread usage of MCR-ALS is the lack of implementation of curve resolution options in commercial chromatographic data systems. Although commercial data systems for spectroscopy instruments (for example, infrared) frequently provide MCR-ALS or related curve resolution tools within their software, this situation is as not common for chromatographic data systems. To the best of our knowledge, only Shimadzu has recently added this capability to its data system software (15). The other option for chromatographers wishing to apply these methods to their data is to use one of the many available MCR-ALS toolboxes available for use in the Matlab programming environment. Eigenvector Research, Inc. sells its PLS Toolbox package, which includes MCR-ALS (16). Matlab toolboxes are freely available from the Barcelona MCR-ALS group (10,17) and the Olivieri group (18), with the latter toolbox specifically focused on calibration applications. The Olivieri and Barcelona MCR-ALS toolboxes are also available for users without access to Matlab through a stand-alone graphical user interface (17,18). There is also an ALS package available for the open-source R statistical software environment (19).

	Because of the lack of integration with instrumental software, an extra step is required to export the raw spectrochromatogram and read it into the third-party software packages listed above. Unfortunately, this approach is not always straightforward, depending on the instrument software. Although a few extra minutes may be required to move the data and to analyze with the third-party software, it will often require less time than it would take to analyze samples using different chromatographic columns or to vary other method parameters to resolve impurity peaks and increase confidence that none are present.

	To those of us who have utilized MCR-ALS for chromatographic analyses, it is clear that this technique adds a powerful tool to the chromatographer's arsenal. While the peak purity approaches described in part I of this series can identify whether impurities are present, MCR-ALS can resolve the pure chromatographic profile, allowing quantitation of the target analyte and the impurity if standards are available for the compound. As mentioned earlier, MCR-ALS does require that compound spectra be at least slightly different; however, MCR-ALS is able to distinguish compounds with even small differences in spectra given a large enough S/N as shown in Figure 3.

	Here we have limited our discussion to impurity analysis in LC–DAD; however, it is worth noting that MCR-ALS finds use in many other analyses such as metabolomics and environmental analyses as well as other instrumental techniques from hyperspectral imaging to LC with mass spectrometric detection to two-dimensional liquid chromatography (3,4,20,21). The latter will be the focus of the next installment in this series where we will look at how the additional separation dimension can help in the quest to determine peak purity particularly when spectrally indistinguishable impurities are present.

	(1) S.C. Rutan, C.J. Venkatramani, and D.R. Stoll, 

	(3) A. de Juan, J. Jaumot, and R. Tauler, 

	(4) D.W. Cook, M.L. Burnham, D.C. Harmes, D.R. Stoll, and S.C. Rutan, 

	(5) S.C. Rutan, A. De Juan, and R. Tauler, in: 

, S. Brown, R. Tauler, and B. Walczak, Eds. (Elsevier, Oxford, 2009), pp. 249–259.

	(6) A. de Juan, S.C. Rutan, and R. Tauler, in: 

, S. Brown, R. Tauler, and B. Walczak, Eds. (Elsevier, Oxford, 2009), pp. 325–344.

	(7) A. de Juan, Y. Vander Heyden, R. Tauler, and D.L. Massart, 

	(10) R. Tauler, A. de Juan, and J. Jaumot, 

	(11) G. Ahmadi, R. Tauler, and H. Abdollahi, 

	(12) R.R. De Oliveira, K.M.G. De Lima, A. De Juan, and R. Tauler, 

	(13) A.C. de O. Neves, R. Tauler, and K.M.G. de Lima, 

	(15) S. Arase, K. Horie, T. Kato, A. Noda, Y. Mito, M. Takahashi, and T. Yanagisawa, 

http://www.eigenvector.com/software/pls_toolbox.htm

	(17) J. Jaumot, A. de Juan, and R. Tauler, 

	(18) S.J. Mazivila, S.A. Bortolato, and A.C. Olivieri, 

https://cran.r-project.org/web/packages/ALS/ALS.pdf

	(21) J.M. Prats-Montalbán, A. de Juan, and A. Ferrer, 

 is the editor of "LC Troubleshooting." Stoll is an associate professor and co-chair of chemistry at Gustavus Adolphus College in St. Peter, Minnesota. His primary research focus is on the development of 2D-LC for both targeted and untargeted analyses. He has authored or coauthored more than 50 peer-reviewed publications and three book chapters in separation science and more than 100 conference presentations. He is also a member of 

's editorial advisory board. Direct correspondence to: 

 is a professor of chemistry at Virginia Commonwealth University (VCU), in Richmond, Virginia, where she has been on the faculty for 33 years. Her research spans a broad range of areas in analytical chemistry and chemometrics, and is currently focused on the development of chemometric methods for improving chromatographic analyses, especially comprehensive 2D chromatography. She has more than 100 publications and numerous presentations on these topics.

 is a senior scientist at Genentech USA and has more than 15 years experience in the pharmaceutical industry. He was the key member of Genentech technical team instrumental in the successful launch of gRed's first small molecule Erivedge, leading from development to commercial. His areas of interest include multidimensional chromatography and ultratrace analysis of genotoxic impurities.

 is a post-doctoral fellow in the pharmaceutical engineering laboratory within the Chemical and Life Science Engineering Department at Virginia Commonwealth University in Richmond, Virginia. In this role, he serves as the primary analytical chemist for the research efforts of the Medicines for All Institute. He received his BS from Randolph-Macon College in 2011 and his PhD in 2016 from Virginia Commonwealth University for his work focusing on the development and application of chemometric techniques to chromatography, particularly comprehensive 2D-LC.

LC Troubleshooting

In part II of this series, we explore how curve resolution methods advance purity assessments and illustrate one of the most popular techniques, which adds a powerful tool to the chromatographer’s arsenal.

Peak Purity in Liquid Chromatography, Part II: Potential of Curve Resolution Techniques

This installment describes high performance liquid chromatography (HPLC) and related products introduced at Pittcon 2018 in Orlando, Florida, and in the year prior. It highlights new HPLC and mass spectrometry (MS) systems, modules, chromatography data systems, and other HPLC-related software and provides brief descriptions of their significant benefits and innovative features.

	The Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy (Pittcon) is one of the world's largest conferences on laboratory science. The 70th Pittcon was held at the Orange County Conference Center in Orlando, Florida, February 26 to March 1, 2018. The last Pittcons held in Orlando were in the years 2012, 2010, 2006, and 2003. Future Pittcon venues will include Philadelphia, Pennsylvania; New Orleans, Louisiana; Chicago, Illinois; Atlanta, Georgia; as well as the new locations of Boston, Massachusetts and San Diego, California. Sadly, Orlando is not on the list for future events.

	Orlando remains my favorite Pittcon location because of the warmer weather, friendly people, great food, and wonderful theme parks. Orlando spans a high tech corridor that encompasses numerous centers of agrochemical, biotechnology, and pharmaceutical manufacturing, and renowned universities.

	This year's Pittcon continued to be impressive, with ~2000 presentations, 100+ short courses, and a large exposition, although the duration of the exposition portion was reduced from four to three days (Tuesday to Thursday). The conference featured plenary lectures by Professor Jeremy K. Nicholson (director of the United Kingdom National Phenome Centre) on precision medicines and Dr. Stefan W. Hell (Max Planck Institute, 2014 Nobel Laureate) on optical microscopy. Pittcon 2018's program was packed full of invited symposia, poster presentations, contributed and networking sessions, and social activities, including a night out to Universal's theme park.

	With ultrahigh-pressure liquid chromatography (UHPLC) firmly established as the modern high performance liquid chromatography (HPLC) platform for more than a decade, all major manufacturers have already introduced the first- and second-generation UHPLC systems (1–3). In the past few years, manufacturers continued to introduce line extensions to existing equipment, such as dual-path, intermediary-pressure, and bioinert systems (4,5). This year's new introductions also appeared to be trending toward application-specific systems (for example, cannabis analysis), front ends to mass spectrometry (MS) systems, micro- and nano-HPLC systems, biopurification systems, portable instruments, preparative LC systems, and integrated HPLC systems for quality control (QC) applications. New MS systems abounded, ranging from single-quadrupole and triple-quadrupole, to quadrupole-time-of-flight (Q-TOF) hybrid MS systems. Updates to existing chromatography data systems (CDS) proliferated, as well as software products catering to HPLC method development, peak deconvolution, pharmaceutical development, and stability testing.

	Table I lists more than 40 new HPLC-related product introductions (arranged alphabetically by vendor name) at Pittcon 2018 or during the prior year, followed by brief descriptions of each product, categorized under systems, modules, CDS, and software products.

New HPLC and UHPLC Systems and Line Extensions 

	This year's new system introductions trended toward UHPLC line extensions, dual-path HPLC systems, integrated HPLC systems for QC applications, micro-, nano-, and prep-LC systems, as well as systems serving as front ends to MS or specific applications.

	Advion Avant HPLC and UHPLC systems-Advion's HPLC and UHPLC systems serve as front ends to Advion's Expression Compact MS (CMS) system and other MS systems. The system consists of a binary gradient pump (10,000 or 18.000 psi) with a 0.1–5.0 mL/min flow range, two available optional photodiode-array (PDA) detectors, an autosampler for microplates or vial trays, and other accessories (column oven, solvent tray, degasser, and post-column derivatization system). The Avant system is controlled by Advion's Mass Express 4.1 software.

	Agilent 1260 Infinity II Prime LC systems-Agilent's 1260 Infinity II LC family now include binary pumps (600 bar) and 800-bar Flexible pumps in the 1260 Infinity II Prime LC systems. Agilent Intelligent System Emulation Technology (ISET) removes method transfer challenges through a single mouse click. With the Agilent InfinityLab LC companion, now all systems are offered with a web browser–based user interface, which allows access from anywhere.

	Agilent InfinityLab Workflow Solutions-Agilent InfinityLab Workflow Solution is an expanded family of HPLC systems configured for specific laboratory workflows, including those for two dimensional (2D)-LC, method development and transfer, impurity analysis, high-throughput screening (HTS), solid-phase extraction, biomolecule and amino acid analysis, supercritical fluid chromatography (SFC), gel-permeation chromatography (GPC), and multimethod analysis in a multiuser walk-up environment.

	Cecil Instruments: Adept HPLC-Cecil Instruments introduced the Adept HPLC system for the analysis of cannabis-associated analytes, including Δ

-tetrahydrocannabinol, cannabidiol, cannabinol, residual pesticides, mycotoxins, terpenes, and many other contaminants.

	PolyLC Smart HPLC-The Smart HPLC system is a low-cost, portable HPLC system (22 lb packed inside a Pelican plastic instrument case) with a fixed ultraviolet (UV) detector with a light-emitting diode (LED) light source (255 or 280 nm), a Valco manual injector, and a binary gradient pump (3000 psi, 0.001–5 mL/min) with onboard reagent and waste bottles. The system can run on a 100–240 VAC line source, vehicle power, or a rechargeable battery power pack (12 VDC) for 9 h. The system comes with the Clarity CDS installed and can be controlled by a tablet or laptop PC. PolyLC is marketing the system as an analyzer for hemoglobin (Smart LifeLC, 414 nm). The Smart LC system is also distributed in North America by Supercritical Fluid Technologies and Vernier Software & Technologies.

	Sciex Jasper HPLC system-The Sciex Jasper HPLC system is a US Food and Drug Administration (FDA) Class I and CE-marked in vitro diagnostic system and serves as the front end to Sciex's MS systems and are designed for targeting applications in clinical diagnostics. They are designed to operate at a maximum pressure of 10,000 psi.

	Shimadzu i-Series Plus HPLC and UHPLC systems-Shimadzu i-Series Plus HPLC and UHPLC systems belong to a family of integrated HPLC systems consisting of Prominence-i, Nexera-i, Nexera-i MT (method transfer), and Prominence-i LT (LC–MS front end) systems. The system has a touchscreen liquid-crystal display for easy system control and chromatogram viewing, a built-in degasser, a quaternary pump, an ultrafast autosampler, and a UV or PDA detector. Pressure limits range from 22 to 66 MPa (220–660 bar). The Nexera-i MT system has a dual flow path and can use Analytical Condition Transfer and Optimization (ACTO) software to facilitate method conversions between HPLC and UHPLC systems by adjusting gradient timings. Other enhancements include a higher column oven temperature limit of 90 °C, pretreatment functions in autosamplers, improved baseline stability for UV detectors, and higher precision for autosamplers for small sampling volumes of 0.5–1 µL.

	Thermo Scientific Vanquish UHPLC systems-Thermo Scientific updated its family of Vanquish UHPLC systems, now consisting of Vanquish Horizon (1500 bar, binary pumps), Vanquish Flex Binary (1000 bar), Vanquish Flex Quaternary (1000 bar, low-pressure mixing), and Vanquish Duo (dual pumps, two flow paths, up to 1500 bar, and dual split sampler) systems for enhanced productivity.

	Teledyne SSI Viper LC-Scientific System, Inc. (SSI), an original equipment manufacturer (OEM) for HPLC pumps, was acquired by Teledyne Technologies in 2017. Teledyne SSI Viper LC is an integrated HPLC system configured as a front end to MS. The system is based on a binary pump (10,000 or 20,000 psi), column oven, and autosampler. It can be controlled by the Clarity CDS or Sciex Analyst drivers.

	Waters Arc Bio system-The Waters Arc Bio system is a dual-path, biocompatible, intermediary-pressure (9500 psi, 5.0 mL/min) UHPLC system designed to facilitate method conversion between UHPLC and HPLC. The system has an iron-free sample flow path and is particularly suited for the analysis of biomolecules, and is controlled by the Waters Empower 3 CDS or Masslynx software.

	YL Instruments: YL9100 Plus and YL9300 HPLC systems-YL Instruments Co., is a Korean manufacturer of gas chromatography (GC) and HPLC instruments. The YL9100 Plus (modular) and YL9300 (integrated) HPLC systems are designed for analytical and semipreparative applications. They can be configured with various pumps (isocratic, binary, and quaternary; 6000 psi and up to 10 mL/min for analytical systems and 3500 psi and up to 50 mL/min for semipreparative systems), autosamplers, column ovens, and detector (UV–vis, PDA, refractive index, and evaporative light scattering) options. The systems are controlled by the YL-Clarity CDS. The company also manufactures post-column derivatization systems based on syringe pumps.

	Micro- and nano-LC with MS detection are ideally suited to bioscience research (biomarkers, "omics" research, clinical testing) and applications in limited sample situations. Here is a description of the new offerings in this area this year.

	Axcend Focus LC-The Axcend Focus LC is an innovative portable nanoflow LC system developed in the research laboratories of Milton Lee during an 8-year fruitful collaboration with Stan Stearns and engineers at VICI Valco Instruments (6). Dr. Lee is Emeritus Professor at Brigham Young University and a serial entrepreneur of micro-LC, SFC, GC, and MS products. The Focus LC system is a hand-portable nanoflow LC system (<15 lb including a 24-V battery) with a binary gradient pumping system (20,000 psi pressure limit), valve injector, and single or dual miniaturized on-column LED UV-absorbance detectors for target analyte detection in a cartridge-type capillary column–detector unit. It can also be easily interfaced to an MS system for unknown compound identification.

	The system exhibits better sensitivity than commercially available UV-absorbance detectors because of the stability of its LED light source, integrated optics, and noise reduction processing (7). It has built-in instrument control, data handling and user interface with smartphones, tablets, and PCs, and uses regular line voltage or internal battery power. The Axcend Focus LC system is the Bronze medal winner of 

's Excellence Award for Pittcon 2018. Figure 1 shows a chromatogram illustrating the performance of this nano LC system.


	Figure 1: A chromatogram of a test mixture of phenols obtained using the Axcend Focus LC system. Column: 170 mm × 150 µm, 3.5-µm C18; mobile phase: methanol-water (0.1% formic acid), 5-95% gradient (10 min) at a flow rate of 1 µL/min; injection volume: 200 nL.

	Bruker nanoElute UHPLC system-Bruker introduced the nanoElute UHPLC system for its Q-TOF and other MS systems in "omics," biomarker, and biopharmaceutical applications. The system is equipped with a single-piston pump of 1300-µL volume, which supports flow rates of 50–2000 nL/min at pressures as high as 1000 bar.

	Shimadzu Nexera Mikros Microflow LC–MS/MS system-Shimadzu's Nexera Mikros Microflow LC–MS/MS system is designed for micro and semimicro HPLC–MS/MS with flow rates of 0.1–500 µL/min (11,600 psi) and direct injections with the SIL-30AC autosampler of volumes as low as 0.1 µL. The new UF-Link adapter is designed to provide reliable, zero-dead volume microcolumn connections. System configurations include those for direct injections, "trap and elute," and makeup flow. These systems are ideally suited for bioanalysis, "omics" research, and biopharmaceutical applications.

	VICI (Valco Instruments) Nano HPLC system-The VICI nano-UHPLC system is designed to be used as the front end to MS systems with a 1500-bar pump with a 35-µL piston capacity and a VICI injector. This pump is used in the Axcend Focus LC system.

	Several new preparative and semipreparative HPLC systems were introduced this year that target preparative and biopurification and workflows currently using flash chromatography or fast protein liquid chromatography (FPLC) with glass columns.

	Agilent InfinityLab Analytical Scale LC Purification Solutions-Agilent InfinityLab Analytical Scale LC Purification Solutions is a family of Agilent 1220-, 1260-, and 1290-based systems targeting purification tasks at microgram to milligram levels. They support preparative applications with automated delay volume calibration and fraction collection into vials, tubes, well-plates, and Eppendorf tubes.

	Agilent InfinityLab Preparative Scale LC Purification Solutions-This family of preparative-scale purification systems is similar to the analytical-scale LC systems described above but at a larger scale, with flow rates up to 200 mL/min. These systems support automated scale-up from analytical scouting runs to microgram- or gram-scale purification. They are suited for a multiuser walk-up environment with automated open-bed or valve-based fraction collections.

	Gilson PLC system-The Gilson PLC system is a unique purification system (100, 250–1000 mL) capable of performing preparative LC, flash chromatography, and centrifugal partition chromatography (CPC, also called countercurrent chromatography, which is known to be advantageous for the purification of labile natural products).

	Knauer Azura Bio LC systems-The Knauer Azura Bio purification systems provide an alternative FPLC platform and are based on Knauer's bioinert analytical or preparative HPLC systems with a flow range of 10–1000 mL/min in a biocompatible layout. These systems are controlled by the PurityChrom CDS. Pressure ratings for Azura systems in stainless steel format are 200, 400, 700, and 1000 bar.

	Teledyne Isco ACCQPrep HP 125-The Teledyne Isco ACCQPrep HP 125 system is an integrated stand-alone preparative LC system designed for flash chromatography users. The system has a built-in control panel for automated purification, detection (UV–vis, evaporative light scatter detection [ELSD], or MS with PeakTrak software), and fraction collection. It has a binary HPLC pump with a flow range of 1–125 mL/min and a maximum pressure of 6000 psi.

	The following descriptions are on newly introduced modules and accessories for HPLC, thin-layer chromatography (TLC), ion chromatography (IC), and MS.

	HTA HT1500L autosampler-HTA is an Italian company that offers robotic solutions for analytical laboratories. The HT1500L autosampler is designed to be a simple, easy to operate, and low-cost autosampler that supports fixed-loop injections to any HPLC system for up to 45 samples.

	JASCO fluorescence detectors-JASCO offers the FP-4020 fluorescence detector, which uses a continuous xenon source and has a sensitivity specification of a signal-to-noise ratio (S/N) of 2300 for the Raman band of water (compared to the company's model FP-4025 system with an S/N value of 1400).

	Advion Plate Express-The Advion Plate Express system provides TLC analysis with MS detection by Advion's Expression Compact MS (CMS) system. It is capable of a 1-min scanning of TLC spots with the automated transfer of separated analytes with a sprayed solvent into the MS system for analyte identification.

	Optimize Technologies OPTI-LYNX 2 Hand Tight system-Optimize Technologies introduced the OPTI-LYNX 2 Hand Tight system, a direct-connect filter–guard column for HPLC and UHPLC columns. A typical OPTI-LYNX 2 precolumn is 5-mm long with an internal diameter of 2.1–4.6 mm and is packed with silica-based or polymeric phases. Direct connection is by hand-tightening to 6000–12,000 psi depending on configuration.

	Peak Industrial Infinity XE 5011 membrane nitrogen generators-The Peak Industrial Infinity XE 5011 family of membrane-based nitrogen generators are capable of producing flow rates of 10–130 L/min with gas purity of 95–99.5% for LC–MS, sample evaporation, nuclear magnetic resonance (NMR) spectroscopy, and ELSD applications.

	Thermo Scientific Dionex DRS 600 Dynamically Regenerated Suppressor-This new suppressor uses a planar packed bed suppression zone for high peak efficiency and suppression capacity. It can be fitted to Thermo's IC system with conductivity detectors and improves gradient performance by drawing optimum currents to suppress the conductivity of the eluents including those with high ionic strengths.

	MS remains an area of active innovations fueled by increasing market demands for systems with higher performance (mass range, resolution, and scan speed) and smaller footprints. The following new single-quadrupole, triple-quadrupole, and Q-TOF MS systems were introduced this year.

	Agilent LC/MSD and LC/MSD XT-Agilent's LC/MSD and LC/MSD XT systems are new stackable single-quadrupole mass selective detectors that support multiple ionization sources (electrospray ionization [ESI], multimode ionization [MMI], atmospheric pressure chemical ionization [APCI], and Agilent Jet Stream [AJS]). These systems have a mass range of 10–2000 

 for XT), a resolution of 0.7 Da, and a maximum scan rate of 10,400 Da/s.

	Agilent Ultivo Triple Quad LC–MS system-Agilent's Ultivo Triple Quad LC–MS system is a new triple-quadrupole system that is stackable with Agilent LC systems and incorporates hardware innovations such as the Vortex collision cell, Cyclone ion guide, and VacShield vacuum system to maximize MS performance with the smallest possible footprint (70% less than its predecessor). Coupled with MassHunter Quant-My-Way software, the system is designed to maximize efficiency for routine analysis. It can be configured with ESI, AJS, APCI, atmosphere pressure photoionization (APPI), or MMI sources. It has a mass range of 5–1400 

, a mass resolution of 0.7 Da, and a maximum scan rate of 15,000 Da/s.

	Agilent 6545XT AdvanceBio LC/Q-TOF system-This Q-TOF system is designed for multiple workflows for biopharmaceutical characterization. When coupled with MassHunter BioConfirm software, this system is designed to generate comprehensive data for intact protein analysis and confirm protein sequences at the peptide level, including post-translational modifications. It has a mass range of 50–30,00 

, a mass accuracy of 2 ppm, a mass resolving power of >50,000 FWHM, and a maximum scan rate of 50 spectra/s.

	Thermo Scientific ISQ-EC MS system-The ISQ-EC single-quadrupole MS system is optimized for detection of low-mass ions required for ion chromatography and some HPLC applications. It supports ESI and has a mass range of 10–1250 

, a maximum scan rate of 20,000 Da/s, and a mass accuracy of 0.1 Da. It is controlled by the Chromeleon 7.2 CDS.

	Thermo Scientific TSQ Altis and TSQ Quantis TQ-MS system-Thermo Scientific introduced two new triple-quadrupole MS systems: TSQ Altis (mass selection of 0.2 FWHM, mass range of 10–2000), and TSQ Quantis (mass selection of 0.4 FWHM, mass range of 10–3000).

	Thermo Scientific Q Exactive HF-X Hybrid Quadrupole-Orbitrap MS system-Thermo Scientific introduced a quadrupole orbital trap hybrid MS system with a mass range of 50–6000 

, a mass accuracy of 1–3 ppm, a mass resolution of 240,000, and a maximum scan rate of 40 Hz.

	Thermo Scientific Orbitrap Fusion Lumos Tribrid MS enhancements-Thermo reported new enhancements for its flagship Fusion Lumos Tribrid MS system that include an integrated ultraviolet photodissociation (UVPD) source (fragmentation achieved by a 213-nm UV laser), Advance Peak Determination for proteomic workflows, and 1,000,000 FWHM in mass resolution. The system is controlled by Thermo Scientific's Xcalibur 4.1 software.

Ion Chromatography and Microfluidic Systems 

	The following descriptions are on newly introduced IC and microfluidic systems.

	Microfluidic ChipShop ChipGenie edition Dx-Microfluidic ChipShop GmbH from Germany introduced the ChipGenie edition Dx, an integrated lab-on-a-chip system designed to provide a universal diagnostic platform for molecular, immunology, clinical chemistry, and cell-based assays. The system uses one-time use chips in cartridge formats coupled with customizable reagents and detection (fluorescence, UV–vis, electrochemical, or sensor) for specified applications. It is interesting to note that one of the first microfluidic instruments, Agilent's 2100 Bioanalyzer, was introduced in 1999 (7000+ units sold), although we saw relatively few new instruments in this category.

	Thermo Scientific ICS-6000 DP Dual Pumps ion chromatograph-Thermo introduced a new high-end ion chromatography system with dual pumps for enhanced flexibility and productivity. It supports capillary, microbore, and standard-bore IC applications (isocratic or gradient) with suppressed conductivity, UV–vis, PDA, or electrochemical detection. It has a PEEK-based flow path with a maximum pressure of 5000 psi (6000 psi capillary) and uses the Chromeleon v.7.2 CDS for system control and data handling.

	The following descriptions are on new major updates in chromatography data systems.

	Agilent OpenLab CDS 2.2-This version of the OpenLab CDS provides a networked or stand-alone environment for instrument control and data handling of Agilent's HPLC, GC, capillary electrophoresis (CE), and single-quadrupole MS systems. Designed with the routine workflows of QC laboratories in mind, this updated CDS features high data integrity, extensive control capabilities for multivendor instruments, and an easy-to-use interface. It works under Windows operating systems (7, 8.1, and 10) and supports web browsers (Internet Explorer 11, Chrome 40, and Microsoft Edge) with multilanguage interfaces including Chinese, Japanese, and Brazilian Portuguese.

	Agilent OpenLab CDS ChemStation Edition-According to Agilent, this CDS software franchise has been updated to meet the needs of the modern laboratory and is ideally suited to diverse environments where flexibility for instrument control is a priority such as for fraction collection, method development, and 2D-LC. The complementary Sample Scheduler add-on automatically ports laboratory information management system (LIMS)-generated worklists to instrumentation and provides a simple user interface.

	Data Apex Clarity CDS Ver. 7.4-This modular CDS (stand-alone or network) is commonly used in many third-party systems and is designed to control hundreds of HPLC and GC instruments and support six languages with optional extensions for PDA, MS, gel-permeation chromatography, natural gas analysis, CE, and elemental analysis. The vendor offers free software updates.

	Thermo Scientific Chromeleon 7.2 SR5 CDS-This updated version of Chromeleon is a multitechnique, multivendor scalable CDS platform (standalone or client-server) for GC, LC, IC, and MS systems with many modern enhancements including unique workflow automation with eWorkflows, and automated mass analysis for LC–MS and GC–MS.

	The following descriptions are on newly introduced HPLC-related software products for method development, impurities management during drug development, stability testing, and peak deconvolution.

	ACD/Labs AutoChrom 2017 version-This updated software platform for HPLC method development has enhanced capabilities for handling biomolecules (peptides and amino acids with standard nomenclatures), improved data import–export functionalities to MS data systems, expanded ability to conduct column screening and selection, and new reporting functions for HPLC method development projects using concepts of quality by design (QbD).

	ACD/Labs Luminata-The Luminata informatics software platform is designed for efficient and comprehensive management of impurity data in pharmaceutical process development that includes organized and searchable databases of analytical and chemical information. This software is intended to provide an effective impurity control strategy in new drug development and includes new visualization tools.

	ChemPower OCAS software for peak deconvolution-LC–MS data can be viewed to provide two dimensions of orthogonal separations with mass-to-charge ratio as the second dimension. ChemPower Technology is a start-up chemometric software company based in Singapore that developed an online chemical analysis system (OCAS) capable of deconvoluting closely eluted peaks from various GC–MS and LC–MS data to discover the molecular identity of unknown compounds. The software can rapidly and accurately process the entire sample data set and provide a list of all the chemicals that are contained in the sample. This type of trending software may provide additional quantitative data for difficult assays (such as biomarkers and stability-indicating assays of complex pharmaceuticals) without invoking the power and tedium of 2D-LC.

	FreeThink Technologies v.5.0 ASAPprime software-Stability testing tends to consume major fractions of analytical resources in many pharmaceutical laboratories. FreeThink Technologies is a software and contract research laboratory company based in Branford, Connecticut, that specializes in stability determinations and solving stability problems. ASAPprime is its flagship software platform (validated for Windows 7/8/10 environments), which is designed to allow accurate determination of the shelf life of drug substances and drug products in about four weeks. The program uses experimental data to estimate the time to hit a specification limit (based on the formation of degradants, loss of assay, or change in dissolution performance) at a range of open temperature and relative humidity conditions, then applies a modified Arrhenius equation with statistical propagation to develop a mathematical stability model for that product.

	The modeling is further enhanced by the program's database of packaging options, which enables users to determine the moisture level a product is exposed to within packaging and combines this level with the moisture sensitivity from the stability modeling. The program can calculate the probability that a product will remain within its specification limits based on different time frames, initial water content, climate zones, and packaging options.

	Molnár-Institute DryLab v.4.3 for HPLC method development-DryLab v.4.3 is the latest version of this popular modeling software platform for HPLC method development. The updates include enhancements for column screening, column comparison displays, and predictions for flow variations. DryLab has a useful cubical display of three-dimensional (3D) resolution maps versus column temperature (

), and mobile-phase pH. It has provisions for multisegment predictions, and automated peak tracking with MS data from specific vendors.

	Shimadzu LabSolutions Insight-This software is designed to be an add-on to the LabSolutions CDS for faster quantitative analysis with Shimadzu's GC–MS and LC–MS/MS systems. It includes more intuitive operation and improved peak integration algorithms and functionalities for supporting data analysis. LabSolutions Insight library screening software supports screening via full scan or multiple reaction monitoring (MRM) mode and can display library search results for multiple analytes. This platform targets applications for food safety and forensic toxicology and provides data reviews by exceptions. This type of review is most useful in HTS applications because it highlights results that appear to be out of specifications or above the regulatory limits.

	S-Matrix Fusion QbD v. 9.8.0-The latest updated version of this popular HPLC method development software platform, which uses principles of QbD and design of experiments (DoE), now includes new simulation chromatogram visualization and reporting capabilities that allow users to display simulated chromatograms in real time.

	Most analytical chemists come to Pittcon for learning the latest in instrumentation, attending seminars and short courses for professional development, and networking with friends and colleagues. My schedule this year included teaching a two-day short course on HPLC and UHPLC, attending several seminars (symposia, workshops, and networking sessions) and an editorial advisory board meeting for 

, and hosting a dinner event sponsored by the Chinese American Chromatography Association (CACA) featuring a lecture on molecular medicine by Professor Weihong Tan of the University of Florida.

	I spent two days on the exposition floor verifying information on the 40+ new HPLC products covered in this installment. I stayed three extra days in Orlando to visit theme parks with my family, thereby narrowly missing the travel frustrations caused by winter storm Riley. I returned home to be confronted by two successive nor'easter storms, Quinn and Skylar, which caused extensive power outages in New England. Indeed, the weather in early March can be unpredictable in North America. Nevertheless, Pittcon continues to inspire me year after year with renewed enthusiasm for my career choice as an analytical chemist, and I continue to look forward to future venues in Philadelphia, New Orleans, and Chicago. However, I do wish that Pittcon will return to sunny Florida again one day.

	This installment provides a brief overview of new HPLC-related product introductions (HPLC systems and modules, MS systems, chromatography data systems, and software and related products) at Pittcon 2018 and during the prior year. Readers are referred to manufacturers' websites and their marketing departments for additional details. Note that new HPLC columns are covered separately in 

's "Column Watch" annual review by Dave Bell (8). The information and opinions expressed in this installment are the author's own and bear no reflections on those of 

, the Pittsburgh Conference, or any other organizations.

	I wish to give thanks to the marketing and editorial staffs of 

 and all HPLC manufacturers for their timely responses to my numerous requests for information. I am particularly grateful for the invaluable editorial and technical input from Davy Guillarme and Szabolcs Fekete of the University Geneva, Wilhad Reuter of PerkinElmer, Christin Gu of Novartis, and Giacomo Chiti of Texsus SpA.

	(2) J. De Vos, K. Broeckhoven, and S. Eeltink, 

	(3) D. Guillarme and M.W. Dong (Eds.), "UHPLC: Where We Are Ten Years After Its Commercial Introduction," 

	(7) X. Xie, L.T. Tolley, T.X. Truong, H.D. Tolley, P.B. Farnsworth, and M.L. Lee, 

 is a principal of MWD Consulting, which provides training and consulting services in HPLC and UHPLC, method improvements, pharmaceutical analysis, and drug quality. He was formerly a Senior Scientist at Genentech, Research Fellow at Purdue Pharma, and Senior Staff Scientist at Applied Biosystems/PerkinElmer. He holds a PhD in Analytical Chemistry from City University of New York. He has more than 100 publications and a best-selling book in chromatography. He is an editorial advisory board member of 

and the Chinese American Chromatography Association. Direct correspondence to: 

An overview and assessment of the latest HPLC and mass spectrometry instruments, modules, chromatography data systems, and related software.


LCGC North America-04-01-2018

New Chromatography Columns and Accessories for 2018

Peak Purity in Liquid Chromatography, Part II: Potential of Curve Resolution Techniques

New HPLC Systems and Relevant Products Introduced in 2017–2018: A Brief Review

Best Practices for Analyzing Pesticides and Their Metabolites in Environmental Samples

Making HILIC Work for You—Column Selection

Data Integrity in the GxP Chromatography Laboratory, Part II: Setting up a Chromatograph and Acquiring Data

Vol 36 No 4 LCGC North America April 2018 Regular Issue PDF