Matrix interferences can impact routine analysis with triple quadrupole methods for monitoring and quantifying PFAS in food.
GC and TLC methods are demonstrated for quantification of stigmasterol 3-O-β-D-glucopyranoside (S3G), the main active component in the herbal nutraceutical Balanites aegyptiaca, an antihyperglycemic in Egyptian folk medicine.
A simple analytical method using high performance liquid chromatography (HPLC) with ultraviolet (UV) detection was developed for the simultaneous determination of four main lignans (niranthin, nirtetralin B, hypophyllanthin, and phyltetralin) in Phyllanthus niruri L. plant samples from Guangxi province.
The common measures of stationary phase polarity—McReynolds constants and the polarity scale—are not always accurate predictors of retentiveness or selectivity in GC.
This modification of ASTM method D8026 for pesticides in environmental matrices includes more pesticides and lowers the reporting limits, thus increasing throughput and measurement capacity for a large surface-water monitoring project.
Multidimensional liquid chromatography (MDLC) methods have revolutionized the characterization of complex drug modalities like antibodies–drug conjugates, antisense oligonucleotides, and small interfering RNA therapeutics.
A comprehensive monitoring protocol has been developed using GC–MS/ECD in selective ion monitoring (SIM) mode, with injection performed by solid-phase microextraction (SPME) and headspace (HS). This single system has been configured to analyze for all taste and odor (T&O) compounds in Standard Method 2170, with minimal changing of columns, injectors, or SPME fibers between methods.
When explosives are encountered on the battlefield, the use of portable GC–MS is valuable for the detection and confirmatory identification of pre- and post-detonation threats. In addition, this technique provides information about the source of explosives based on the detection and identification of trace-level chemicals in the sample. The data presented here confirm this capability.
Limitations often arise when using GC with quadrupole-based mass spectrometers for detecting volatile and semivolatile contaminants. Enter HRAMS-MS.
A new free simulator is available for students, educators, and trainers to teach and perform virtual HPLC experiments that are applicable to real HPLC instrumentation and method development.
Commercially available trypsin IMERs can digest proteins with high sequence coverage and robustness, facilitating online multidimensional LC–MS.
OECD-compliant amino acid derivative assay (ADRA) testing and method transfer to UHPLC conditions is presented.
A novel liquid chromatography–tandem mass spectrometry (LC–MS/MS) method with a dual electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI) source was developed for analysis of 66 pesticides and 5 mycotoxins regulated by the State of California in medium-chain triglyceride (MCT) oil cannabis tinctures. The limits of quantitation (LOQs) of all of the pesticides and mycotoxins were well below California state action limits of these analytes in cannabis-based non-inhalable or edible products. A total of 62 (out of 66) pesticides and 5 mycotoxins were analyzed using LC–MS/MS with an ESI source, and the remaining 4 pesticides were determined using LC–MS/MS with an APCI source. A simple, fast, and cheap acetonitrile solvent extraction method was used for sample preparation to get good recovery and achieve high throughput for this analysis. For late-eluted analytes, a number of internal standards were used to compensate for ion suppression effects from the hydrophobic matrix.
Errors arising from the DNPH approach commonly used to analyze carbonyl compounds in smoke from heat-not-burn (HNB) tobacco can be avoided by using the approach described in this study.
Displacement chromatography is a viable alternative to elution chromatography, but the biotechnology industry has yet to fully exploit this technique. The authors present results of a pilot-scale ion-exchange displacement process developed for the removal of variants from recombitant human brain-derived neutrotrophic factor.
The impact of extracolumn dispersion on kinetic plot curves is investigated. A web-based calculator that allows users to make their own kinetic plots with examples of how the tool can be used to troubleshoot underperforming columns and support column selection is discussed.
Commercially available trypsin IMERs can digest proteins with high sequence coverage and robustness, facilitating online multidimensional LC–MS.
Overcoming the challenges of food and beverage analysis with ion chromatography (IC).
Extractable and leachable (E&L) testing for finished pharmaceutical products, bioprocess manufacturing systems, and medical devices is currently a subject of intense interest. The majority of the challenges encountered in analytical workflows are related to the highly complex matrices and relatively low analyte evaluation thresholds seen in E&L studies. This paper provide options for executing E&L testing to supporting regulatory submissions. There are multiple compliant routes possible, and the presented workflows and analytical solutions are only one of multiple successful approaches.
This method for PFAS analysis in milk and infant formula is robust, reliable, and reproducible, with scope to expand the list of PFAS in the future.
A fully automated quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and extract clean-up method is described for analysis of organophosphate pesticides in orange juice. This method uses GC–MS and LC–MS along with an industry standard robotic x,y,z-sampling system.
The advantages of a native anion exchange method coupled to mass spectrometry for charge heterogeneity analysis of immunoglobulin G4 (IgG4)-based mAbs are described.
Integrating electric fields into extraction techniques increases sensitivity and selectivity. These approaches are compatible with miniaturized, portable, and many biological samples.
Monoliths are chromatography sorbents cast into columns as a single continuous piece in contrast with regular chromatographic sorbents, which are packed as individual particles. The guest authors compare three such novel sorbents with a conventional particle-packed column.
Commercially available trypsin IMERs can digest proteins with high sequence coverage and robustness, facilitating online multidimensional LC–MS.
Webinar Date/Time: Wednesday, October 18th, 2023 12:30 pm BST 7:30 am EDT 13:30 pm CEST Thursday, October 19th, 2023 12:30pm BST | 7:30am EDT | 13:30pm CEST
Guest author Reg Cross discusses strategies for collecting samples from large masses of material. He also describes the problems associated with acquiring truly representative samples for analysis.
This GC–FID method enables accurate determination of cooling agents, which are flavor compounds commonly used in cigarette tipping paper.
The authors compare their results in analyzing styrene–butadiene block copolymers by gel permeation chromatography with other methods, such as Fourier transform infrared spectroscopy and pyrolysis gas chromatography.