An Inside Look at the Irish Whiskey Industry

Examining Volatile Aromatic Congeners in Irish Whiskey Using GC–MS and GCO

Suspect Screening of Lupin-Produced Phytotoxins in Environmental Samples

A Look Back at the 51st International Symposium on High Performance Liquid Phase Separations and Related Techniques

Highlights from HPLC 2023

A Look at Targeted Multispecific Antibody Cancer Therapeutics

Overcoming Complex Analytical Challenges

Advances in Multiwavelength Absorbance Detection

, the leading resource for separation scientists, is proud to announce that Wolfgang Lindner and Martina Catani are the winners of the 17th annual Lifetime Achievement and Emerging Leader in Chromatography Awards. Lindner and Catani will be honored in a symposium as part of the technical program at the Pittcon 2024 conference in February.

Wolfgang Lindner is the winner of the 2024 Lifetime Achievement in Chromatography Award. 

The Lifetime Achievement in Chromatography Award honors an outstanding professional for a lifetime of contributions to the advancement of chromatographic techniques and applications.

Lindner, professor emeritus in analytical chemistry at the University of Vienna and the 2024 winner, has made significant contributions in liquid chromatography (LC) and the development of chiral drugs. He has developed and licensed several chiral stationary phases that have been widely used by both researchers and the pharmaceutical industry. He has applied separations of enantiomers to pharmacokinetics of chiral drugs and to metabolomics of endogenous compounds, such as amino and hydroxyl acids.

The focus on Lindner’s research has been molecular recognition, understanding the non-covalent binding of the analyte to be separated with the chiral stationary phase, including the contributions of the associated mobile phase components. He has also created highly selective mixed mode and hydrophilic interaction liquid chromatography (HILIC) phases as well as arginine modifications for liquid chromatography-tandem mass spectrometry (LC–MS) analysis of highly basic peptides. In all cases, he has focused on the fundamental physico-chemical principles to create highly selective separations.

In the 1980s, Lindner introduced O,O-diacyltartaric acid anhydrides as chiral derivatizing agents for diastereoisomer separations. These agents were commercialized and are still in use for analysis and the production of enantiomerically pure drugs. In the 1990s, he developed and licensed cinchona-based (quinine) chiral anion exchange columns that have been widely used, both at the analytical and preparative scale.

His most important advancement occurred with the creation of chiral zwitterionic stationary phases for the separation of positive, negative, and ampholytic compounds. Taking a highly creative approach, Lindner combined a chiral amidosulfonic acid with the basic quinine and quinidine type scaffolds. Over the years many of these columns have been licensed and commercialized, both at the analytical and preparative scale, and have had significant impact in the pharmaceutical industry.

Martina Catani is the winner of the 2024 Emerging Leader in Chromatography Award. 

The Emerging Leader in Chromatography Award recognizes the achievements and aspirations of a talented early-career separation scientist who has made strides early in their career toward the advancement of chromatographic techniques and applications.

Catani is an assistant professor of analytical chemistry at the University of Ferrara and the 2024 winner. Her research focuses on the purification of polypeptides, oligonucleotides, and proteins by means of single-column and continuous countercurrent multi-column preparative liquid chromatography (LC); separation of natural cannabinoids; and investigation of kinetic and thermodynamic phenomena in chiral and achiral high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). These studies contributed to the revival of the debate about the best particle characteristics for high-efficiency separations.

She has also worked on the development of purification methods for therapeutic bio-macromolecules using both single-column and continuous multicolumn preparative liquid chromatography.

Catani actively collaborates with industry leaders to solve real-world problems. She’s worked closely with the multinational pharmaceutical company Fresenius Kabi iPSUM on the development of continuous purification methods for therapeutic peptides and with Merck on the purification of a carrier protein for vaccines through captureSMB on affinity resins.

In 2018, Catani was awarded the Csaba Horvath Award, which is presented annually to a separation scientist under the age of 35 at the HPLC conference. She is also the recipient of the 2021 Young Researcher Award conferred by the Analytical Chemistry Division of the Italian Chemical Society.

Catani has spent time researching at VUB Brussels in Belgium under Gert Desmet, and at the University of Pécs in Hungary under the supervision of Attila Felinger. In 2019 she was a postdoctoral research fellow at ETH Zurich in Switzerland in the group of Massimo Morbidelli.

 or for information on how to nominate a candidate for the 2025 

Events

LCGC International is proud to announce that Wolfgang Lindner and Martina Catani are the winners of the 17th annual Lifetime Achievement and Emerging Leader in Chromatography Awards. 

LCGC Announces the 2024 Winners of the Lifetime Achievement and Emerging Leader in Chromatography Awards

As chromatography technologies change, our approaches to using them in ways that value reliability, as well as the ways we should approach troubleshooting and fixing problems, should also change. In this installment, I continue the discussion started last month about how some specific troubleshooting topics have evolved over time, this time focusing on mobile phase degassing. Understanding how approaches to degassing have evolved is helpful for troubleshooting problems with pumps and detection, designing reliability into new methods, and when considering updates to legacy methods that have been in use for decades.

 is the editor of “LC Troubleshooting”. Stoll is a professor and the co-chair of chemistry at Gustavus Adolphus College in St. Peter, Minnesota, USA. His primary research focus is on the development of 2D-LC for both targeted and untargeted analyses. He has authored or coauthored more than 75 peer-reviewed publications and four book chapters in separation science and more than 100 conference presentations. He is also a member of LCGC’s editorial advisory board. Direct correspondence to: 

In recent months, I’ve been hearing from several readers of this column that they’ve appreciated the more educational, “back-to-basics” flavor of some of the “LC Troubleshooting” installments in the last year. So, last month I decided to dip a little further into that theme and provide some perspective on the evolution of various troubleshooting topics over the last few decades. My view is that this kind of perspective is particularly valuable to those who are relatively new to the field. There are some aspects of “the way we do things” that may seem peculiar on the surface, but are in fact very important to the reliability of high-performing liquid chromatography (LC) methods. On the other hand, some aspects of certain methods and ways of doing things are simply unnecessary in 2023 because LC technology has evolved in such ways that the old tricks aren’t needed anymore. Sometimes implementing the old tricks with new technology – though they provide no benefit – doesn’t do any harm, but they do add cost to analyses because they take time and resources to implement. Thus, we really ought to let them go if they are not adding any value to the method. In other words, let’s be smart about the methods we deploy. If we can’t come up with a better explanation for why something about the method is the way it is, then it’s time to let it go. In this installment, I will discuss the evolution of degassing in liquid chromatography. In general, degassing has become much more convenient, to the extent that most users probably rarely think about it anymore. However, some of the older techniques are still useful, and even with modern techniques it is useful to have a broad sense for how things have changed, as this can impact proper instrument operation when working with different generations of equipment. Readers interested in learning more details about the degassing topic are referred to previous installments of “LC Troubleshooting” (1,2), Dolan’s book on LC troubleshooting (3), and a very old, but very rich, paper by Bakalyar and coworkers (4).

In most applications, the biggest problem with gas bubbles inside of an LC system is that pumps generally don’t deal with the bubbles very well (see the last section below for other problems that can be significant in some applications). In the worst cases, a gas bubble can cause one or both of the check valves in a high-pressure pump to fail, causing a highly erratic flow or no flow at all. Where, then, do these bubbles come from? Although there are multiple mechanisms that can lead to bubble formation, the most practically relevant one in LC is the situation where two solvents are brought together to make a mixture (here, the mobile phase) that has a lower gas solubility than either of the individual solvents alone. This is most problematic with pumps that use the “low-pressure mixing” design. For a refresher on the differences between low-pressure and high-pressure mixing designs used in LC pumps, readers are referred to previous articles in this magazine (5). In the case of low-pressure mixing, the individual solvent components are brought together under nominally atmospheric pressure conditions before a high-pressure pump provides the force needed to push the mixture through the rest of the LC system.

An example is valuable for illustrating the point here. The solubilities of oxygen gas at room temperature and atmospheric pressure in water or ethanol are about 0.3 × 10

, respectively (4) (albeit on a mole fraction basis, meaning moles of oxygen relative to the total moles of oxygen and solvent). In other words, when saturated with oxygen, ethanol carries about 20 times more oxygen dissolved in the solvent compared to water. If we mix the two solvents in equal parts, then the amount of oxygen present in the mixture initially will be about 3.0 × 10

 (mole fraction). However, the solubility of oxygen in a 0.5 (mole fraction) mixture of water and ethanol is only about 1.8 × 10

 (mole fraction). This difference of 1.2 × 10

 is the amount of oxygen in excess of the carrying capacity of the mixed solvent at saturation, and this excess will manifest in the formation of significant bubbles. In a low-pressure mixing pump, these bubbles will be drawn into the pump, and may cause failure of one or both check valves. So, in this example, avoiding the problem requires that the concentration of gas dissolved in each of the individual solvents is decreased prior to mixing such that the gas concentration in the mixed solvent (mobile phase) is lower than the solubility limit of the gas in that solvent. If this is achieved, then bubble formation will not be nearly as serious. A different way of thinking about the same problem is to consider the volume of gas that will be evolved as bubbles upon mixing of two solvents. Figure 1 shows data along these lines from the work of Bakalyar and coworkers (who physically measured the volumes of bubbles formed using an apparatus for trapping the bubbles) for mixtures of methanol or acetonitrile with water (4). We see that the volumes can be quite remarkable – 60 μL of gas per milliliter of mixed solvent! – and that these volumes roughly maximize around 50:50 mixtures of the organic solvent and water.

FIGURE 1: Gas evolved from different mixtures of solvents commonly used in reversed-phase LC. Adapted from (4).

The situation with pumps that use a high-pressure mixing design is quite different. In this case the mixing point for the mobile phase components is downstream from the high-pressure pump heads, and the pressure at which the mixing occurs will be nominally the same as the column inlet pressure (that is, well above atmospheric pressure). Under these conditions the gas solubility in the mobile phase will be much higher and bubbles will not form while the liquid is under pressure. However, as the pressure drops toward atmospheric pressure at detector, bubbles may form when the gas concentration reaches the solubility limit in the mixed solvent. If bubbles form in an optical flow cell (for example, ultraviolet-visible (UV-vis) or fluorescence), this can lead to unstable baselines, including spiking patterns.

Survey of Degassing Techniques, Old and New

Including older discussions of degassing techniques used in LC, the list includes: heating, sparging, refluxing, sonication, offline vacuum degassing, and inline vacuum degassing. I personally am not aware of anyone currently routinely using heating or refluxing for degassing, and I won’t discuss those approaches further here.

I like to think of sparging as a technique that “scrubs” dissolved gases from a liquid. The principal fact in play here is that helium is much less soluble in LC solvents than other gases, including oxygen and nitrogen. In methanol, which is particularly problematic as discussed above, the solubilities of these three gases at room temperature and atmospheric pressure are about 0.7 × 10

 (mole fraction), respectively (4). To use the sparging approach in practice, helium is deliberately bubbled into a LC solvent. Other gases dissolved in the liquid diffuse into the helium bubbles and are carried out of the liquid as the helium bubbles rise to the surface. After an initial scrubbing period (15 minutes of sparging will remove about 80% of the oxygen dissolved in methanol [6]), the “gas-free” solvent can be maintained on the instrument with a very low flow of helium into the solvent bottle. Helium sparging has fallen out of favor due to the introduction of other approaches (mostly inline degassing, discussed below), practical inconvenience (nobody wants to deal with compressed gas cylinders if they don’t have to), and the cost of helium, meaning it is not commonly used today. That said, I do still have LC instruments in my laboratory that have the necessary plumbing and sparging stones to support this approach.

A very simple approach to degassing is to simply place a bottle of solvent to be used on the LC instrument in an ultrasonic bath for several minutes before use. Unfortunately, this approach is not very effective; fifteen minutes of sonication will only remove about 30% of the dissolved oxygen dissolve in methanol (6).

In the offline vacuum degassing approach, a vacuum is applied to a bottle containing the solvent that will ultimately be used on the LC. The most convenient and safe source of vacuum would be a house vacuum system, as found in many laboratories. The fundamental idea here is that reducing the pressure in the bottle decreases the solubility of gases dissolved in liquid, and any gas present above the solubility limit will spontaneously bubble out of the liquid. The vacuum can be applied using a sidearm type of flask with a hosebarb connection, or a plastic bottletop adapter with a hosebarb fitting that can be used to connect to the bottle to the vacuum source. When using this approach, great care should be taken to ensure that the container placed under vacuum is not physically compromised with cracks or other defects, as this could lead to a dangerous implosion of the container. Using a safety shield when the bottle is under vacuum is a good idea. Users should also be careful to use an explosion-proof vacuum pump if using a pump as the vacuum source, particularly when working with solvents that produce explosive vapors.

In my laboratory, we have found it most effective to combine offline degassing and sonication. The additive effects of the two approaches are both visibly obvious and unforgettable. As a demonstration, I suggest preparing a 50:50 mixture of acetonitrile and water, and placing the mixture under vacuum until no bubbles are observed. Then, while the bottle is still under vacuum, place the bottle in an ultrasonic bath. A vigorous rush of bubbles will be observed, and then completed within seconds. Although we only use inline degassing (see below) for routine degassing of solvents on LC instruments in my lab, the combination of offline vacuum degassing and sonication is still very useful in situations where a complementary degassing approach is needed. For example, if one suspects that the inline degasser in a pump is not working, and leading to bubble formation, degassing the solvent offline can enable a very informative test of the rest of the system to rule out the possibility that the inline degasser is the source of the problem.

A simple block diagram illustrating the use of inline vacuum degassing in LC pumps is shown in Figure 2. In this approach, the solvent is drawn from the bottle through a polymeric tube situated inside of a vacuum chamber on its way to the inlet check valve of the pump (in the case of a high pressure mixing design) or a proportioning valve (in the case of a low-pressure mixing design). The polymer chosen for the tubing inside the vacuum chamber is one that is permeable to the major gases dissolved in the solvent that we need to remove (mainly nitrogen and oxygen), such that gas molecules are drawn across the tube and removed from the liquid selectively. Following the discovery in the early 2000s of particular polymers with enhanced permeability for these gases (7), inline vacuum degassing has become the dominant means of degassing used in LC instruments today. In general, it is easy to use (no manipulation by the analyst) and quite robust (except for an occasional vacuum pump failure or leaky fitting). One important aspect to keep in mind when using inline degassers is that molecules other than dissolved gases that are small and volatile can also cross the tubing wall and be swept away by the vacuum pump. When using pre-mixed solvents (that is, mixed in the solvent bottle so that a mixture such as methanol/water enters the degasser), this means that the composition of the solvent exiting the degasser module will be different from the composition of the solvent entering the module, due to preferential loss of the more volatile component of the solvent. For example, an acetonitrile/water mixture will contain a little less acetonitrile exiting the degasser than it did entering it. For most applications these changes will not be large enough to affect method performance, but some applications that are more sensitive to solvent composition may be affected. Similar effects on the solvent composition occur with other degassing methods, including sparging and offline degassing, so this is not a problem unique to inline degassing.

FIGURE 2: Block diagrams for a LC pump with a low pressure mixing design. The inline vacuum degasser is placed between the solvent bottles and the proportioning valve.

Older models of inline vacuum degassers relied on long lengths of less permeable tubing compared to the polymers used in newer models. A practical consequence of this is that the volumes of liquid inside older degasser modules (sometimes referred to as the holdup volume of the degasser) were much larger than they are now. This can be important for two reasons: 1) when working with a newer instrument, the analyst may not need to flush the degasser as long as they had to with an older module when changing solvents; and 2) conversely, when moving to work with an older instrument or an instrument from a different vendor, the degasser flushout time used when changing solvents may need to be adjusted to account for different holdup times. In every case, users should either consult the user manual for the particular model of degasser they are using to find out what the degasser holdup volume is, or a find a recommendation for the flushout volume for the degasser when changing solvents.

In addition to the effect of dissolved gases on bubble formation and pump performance, these gases can also affect detection in LC. For example, Brown and coworkers showed that there can be a 400 mAU difference in the absorbance of methanol at 210 nm when the solvent is fully degassed compared to when it is saturated with air (6). Thus, if degassing efficiency varies over time, this variation can lead to detector baseline drift (long-term changes) or waves in the baseline (short-term changes). Moreover, Bakalyar and coworkers showed that changes in the level of dissolved oxygen in the mobile phase significantly affected the fluorescence signal for some analytes in an application focused on the quantitation of polyaromatic hydrocarbons (4). Here, variations in degassing efficiency could have significant effects on the quantitative performance of methods using fluorescence detection.

In this installment of “LC Troubleshooting,” I’ve discussed the importance of degassing solvents used for liquid chromatography, as well as older and newer approaches to the task. The primary problem that can be avoided with proper solvent degassing is bubble formation, which can cause erratic or even no flow from the LC pump. While inline vacuum degassing is currently the dominant approach used in commercially available instruments, there certainly are situations where older approaches, including sonication and offline degassing, are still useful. Understanding the history of these practices, and how they have evolved over time, is a useful facet of knowledge for aspiring LC troubleshooters.

(1) Dolan, J. W. Mobile Phase Degassing: What, Why, and How. 

(2) Dolan, J. W. How Does It Work? Part II: Mixing and Degassing. 

Troubleshooting LC Systems: A Comprehensive Approach to Troubleshooting LC Equipment and Separations

(4) Bakalyar, S. R.; Bradley, M. P. T.; Honganen, R. The Role of Dissolved Gases in High-Performance Liquid Chromatography. 

(5) Stoll, D. R. Mixing and Mixers in Liquid Chromatography – Why, When, and How Much? Part I, The Pump. 

(6) Brown, J. N.; Hewins, M.; Van Der Linden, J. H. M.; Lynch, R. J. Solvent Degassing and Other Factors Affecting Liquid Chromatographic Detector Stability. 

(7) Sims, C.; Gerner, Y.; Hamberg, K. Vacuum Degassing. US6248157B1, June 19, 2001.

 is the editor of “LC Troubleshooting.” Stoll is a professor and the 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 75 peer-reviewed publications and four book chapters in separation science and more than 100 conference presentations. He is also a member of 

’s editorial advisory board. Direct correspondence to: 

Mobile phase degassing has become very useful for troubleshooting problems with pumps and detection.

The Evolution of LC Troubleshooting: Degassing

 is seeking nominations for the 16th Annual Lifetime Achievement in Chromatography award, to be awarded in 2025. 

 Lifetime Achievement in Chromatography Award, as its name implies, recognizes a separation scientist for his or her overall contributions to the field of chromatography. The winner, chosen by an independent committee, will be featured on the cover of a 2025 issue of 

 and in an interview that will be featured in our electronic newsletter, e-Separation Solutions, and on the 

To nominate a candidate, please use the below form to provide the information listed below about the person you are nominating.

Please email the completed form to Caroline Hroncich, the editorial director of 

Candidate’s full name:           

Current job title (if retired, please indicate that and include last known job title before retirement):      

Area(s) of focus of work (maximum 200 words):      

Short summary, in 100 words, of the candidate’s achievements or contributions (more details can follow in the sections below):      

Please list the candidate’s most important contributions to the field of chromatography and explain briefly the significance of each (maximum 800 words):

Number of oral and poster presentations at scientific conferences: 

Service provided to the scientific community, such as volunteer work in scientific societies, organizing conferences, work as a journal reviewer, teaching short courses, mentoring young scientists, and so on. Please quantify where possible (e.g., number of students in short courses): 

Nominations and questions should be sent to Caroline Hroncich, the editorial director of 

Articles

Nominate a colleague for the 2025 LCGC Lifetime Achievement in Chromatography Award!

2025 Lifetime Achievement in Chromatography Award Call for Nominations

 is seeking nominations for the 15th Annual Emerging Leader in Chromatography award, to be awarded in 2025.  

 Emerging Leader in Chromatography award recognizes the achievements and aspirations of a talented young separation scientist who has made strides early in his or her career toward the advancement of chromatographic techniques or applications. The winner will be featured on the cover of a 2025 issue of 

 Emerging Leader in Chromatography award must work in the field of separation science. In 2025, candidates must be within 10 years of receiving their highest degree, and must have made significant practical contributions to the field of separation science that have helped advance the state of the art in the fundamentals or application of chromatography. Weight will be given to candidates who have taken a leadership role at their university, institute, or place of business. 

You may nominate a colleague or yourself. To nominate a candidate, please email the following documents to Caroline Hroncich, the editorial director of 

The form will ask you to provide the following information:

Year highest academic degree was earned and from where (list degree, year, institution, and location). 

Important: Candidates must be within 10 years of receiving their highest degree in the year the award is presented.

Short summary, in 100 words, of the candidate’s achievements or contributions (more details can follow in the sections below)

Please list the candidate’s five most important pieces of work (such as papers in peer-reviewed journals, technical reports written in an industrial community, patents, or other) and explain briefly the significance of each. 

Other key contributions to the field of separation science not captured above

Number of oral and poster presentations at scientific conferences

Please include a maximum of two letters of support from members of the separation science community. (Additional letters will not be considered during the voting process.) Information in the supporting letters should complement, not repeat, the information contained in the nomination form.

Please provide a current resume or CV of the candidate in a Word or PDF file.

Include a high-resolution headshot of the nominee in a .JPG format.

Submissions and questions should be sent to Caroline Hroncich, the editorial director of 

Nominate a colleague for the 2025 LCGC Emerging Leader in Chromatography Award!

2025 Emerging Leader in Chromatography Award Call for Nominations

Lab Innovations is the United Kingdom’s main trade exhibition for scientific suppliers and manufacturers. Over the course of the two-day trade show, the latest technologies and products designed for the laboratory will be on display. Scientific suppliers and manufacturers provide the entire laboratory community a chance to gather under one roof.

city skyline of Birmingham business district, West midlands, UK | Image Credit: © nakarat4 - stock.adobe.com

Many of the products that will be on display are applicable to a wide variety of industries. Some of the most common sectors include life sciences, pharmaceuticals, academia, healthcare, chemical, food and drink, cleanroom, and water and wastewater treatment.

Attendees at Lab Innovations can look forward to several events. Along with ample opportunities for networking, the Lab Awards on November 1st recognizes those in the industry who had significant achievements and success from the previous year. Taking place at The Vox, in Birmingham, United Kingdom, the Lab Awards encapsulates the trade show by giving credit to those who significantly contributed to the advancement of laboratory technologies.

To learn more about this upcoming trade show and the Lab Awards, click on the link below: 

Lab Innovations 2023 will be held 1–2 November 2023 in Birmingham, United Kingdom. Here’s a sneak preview of what attendees can look forwards to.

Event Preview: Lab Innovations 2023 

Patrick Lavery is an Editor for the MJH Life Sciences brands LCGC and Spectroscopy, and their respective websites, 

. He previously spent nearly a decade as a news anchor, reporter, and producer at New Jersey 101.5 FM.

On Wednesday, Sept. 13 in Manchester, England, UK, Alexander Makarov, scientific director for Global Research for Life Sciences Mass Spectrometry at Thermo Fisher Scientific, received the Aston Medal, the most prestigious scientific distinction awarded by the British Mass Spectrometry Society (BMSS) (1).

Makarov was honored, according to a BMSS news release, for his “pioneering work” in mass spectrometry, namely the development of Thermo Fisher’s Orbitrap ion trap mass analyzer—which acts as both an analyzer and detector and is widely used by separation scientists (1). The Aston Medal has been given out since 1987, with this year’s award presented at the 43rd annual BMSS conference.

Makarov is also a professor of high-resolution mass spectrometry in the Department of Chemistry at Utrecht University in The Netherlands. His work on the Orbitrap began, according to 

 after he received his PhD from the Moscow Engineering Physics Institute in Moscow, Russia and completed two years of post-doctoral work at Warwick University in Coventry, England, UK, during his time at HD Technologies, which was acquired by Thermo in 2000.

 Makarov’s receipt of the 2008 American Society for Mass Spectrometry (ASMS) Distinguished Contribution in Mass Spectrometry award and, 

 the first-ever Human Proteome Organization (HUPO) Science and Technology Award, both also for his role in developing the Orbitrap.

(1) Prof. Alexander Makarov is Awarded the Aston Medal. 

https://www.bmss.org.uk/mediacentre/news/prof-alexander-makarov-is-awarded-the-aston-medal/

Alexander Makarov was awarded the honor first introduced by the British Mass Spectrometry Society in 1987.

Orbitrap Developer Makarov Receives Aston Medal from BMSS

During a session at the Cannabis Science Conference on September 21, Zacariah Hildenbrand, PhD, a research professor in the Department of Chemistry and Biochemistry at the University of Texas, El Paso gave an overview of various analytical methods that are useful in cannabis analysis. "Cannabis is a versatile plant, with many different compounds in its makeup," Hildenbrand said. Enzymes such as cannabigerolic acid (CBGA), tetrahydrocannabinolic acid (THCA), and cannabidolic acid (CBDA) can all have different effects. Commercial testing protocols vary state by state, which can make it difficult to characterize different products.

“It's absolutely critical that we do this with a high degree of accuracy,” he said. “If you don't have the dosing dialed in, which is predicated on accurate testing, then someone can really have a horrible experience.”

To properly separate these compounds, complex instrumentation is required, with techniques such as high-performance liquid chromatography–ultraviolet (HPLC-UV) and headspace gas chromatography–flame ionization detection (GC-FID). Inductively coupled plasma mass spectrometry (ICP–MS) and inductively coupled plasma–optical emission spectroscopy (ICP–OES) can be useful in finding toxins, and quantitative polymerase chain reaction (qPCR) for detecting DNA of different species. Matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI–TOF-MS)can be usedfor characterizing bacteria.

There are also other factors that can complicate cannabis testing, including unreliable laboratories that may run faulty analyses. Because of this, having proper data analysis and troubleshooting procedures is vital to safe and proper cannabis consumption.

Hildenbrand concluded by emphasizing the importance of paying attention to instruments used in commercial testing, specifically regarding calibration and peak shifts.

“If you're not following that key shift and you're not calibrating on a regular basis, you're missing signal, or you put could be mischaracterizing individual species,” he said.

Hildenbrand, Z. Getting the Most Out of Analytical Testing. In 

At the Cannabis Sciences Conference, Zacariah Hildenbrand held a talk which focused on various analytical methods and how they affect the cannabis production process.

Ensuring Reliable Cannabis Analysis

While it is customary and necessary to test for things like mold, mildew, and E. coli in agricultural products, testing for all pathogens should be done to ensure a successful cannabis crop, according to Scott Churchill, vice president of scientific development for MCR Labs, based in Framingham, Massachusetts, USA (1).

Sprout of cannabis (marijuana) on a light background with a broken arm in the background with a gesture OK. | Image Credit: © Konstiantyn Zapylaie - stock.adobe.com

Churchill spoke on the topics of screening and prevention in a lecture titled “Pathogens: Why, Where and How,” presented at the Cannabis Science Conference in Providence, Rhode Island, on September 21.

“A lot of pathogens can impact your plan that do not show up in a regulatory compliance test, or if they do, it’s going to be too late to get your full yield,” Churchill said in his presentation. “The only way that you can offset this to prevent this from happening to get a full crop yield is if you have a monitoring and management system that allows you, or you in combination with the laboratory, to identify them.”

A grower may not be able to assess pathogen-caused problems with their yield by sight, such as observing damping off or yellowing, or even weight, Churchill said, but those or other characteristics appearing as normal could mask a reduction in potency of the cannabis being cultivated. Worse yet, pathogen contamination can result in a change in genetics itself that might lead to the death of one or multiple strains of the plant, Churchill said.

The first line of defense is the cultivator, and Churchill went on to review the differing ways cultivators can best monitor pathogen exposure in and out of the lab, from the leaves down to the stems and roots. But moreover, he said, identification in the first place is key, because misdiagnosis as a lighting or watering problem could mean pathogens are still lying in wait in the soil, waiting to infect the next crop, whether it be cannabis or something else.

Two recommendations Churchill made for prevention were starting with what he called “clean stock” that ensures clones of unknown pathogenic content are not being introduced and running effective plants through multiple cycles of tissue culturing to strip out infections and return a specimen to its original genetics.

These concerns, he said, have become ever more magnified in the last decade as the cannabis market has become legalized and regulated for both medical and recreational use.

“When you translocate plants from different regions, that has to be done with extreme care, because if you bring a plant that’s infected to an area that doesn’t have any natural defense against it, it can run amok very quickly,” Churchill said. “You don’t want people smoking mold or being exposed to bacteria and so forth, but you also want to have a successful grow operation in a successful industry.”

(1) Churchill, S. Pathogen Testing: Why, Where and How. Presented at the Cannabis Science Conference, Providence, Rhode Island, September 21, 2023.

In a presentation at the 2023 edition of the Cannabis Science Conference, Scott Churchill made two main recommendations for growers to head off the spread and invasiveness of pathogens.

Screening for and Preventing Pathogens in Cannabis Crop Growth

At the Cannabis Science Conference in Providence, Rhode Island on September 22, Christopher Hudalla of ProVerde Laboratories, Inc. delivered a talk titled, “LC–MS Analysis of Phospholipids for the Degumming Optimization for Hemp/Cannabis Extracts.” This talk was a part of the analytical sub-track “Analytical Chemical Analysis II” at the Cannabis Science Conference.

Hudalla discussed the overall cannabis extraction process. Historically, cannabis extractions focused primarily on cannabinoids and terpenes (1). There are a variety of processes that can be used to extract and process cannabis. Each process leads to a different consistency and these processing methods are often aimed at minimizing the extraction of phospholipids from the raw plant material (1).

Phospholipids (PPLs) are essential components found in all cell membranes, including those in plant-based oils. In various food oil processing, a common practice known as "degumming" is employed to eliminate PPLs, enhancing the physical stability of oils and facilitating their processing (1). However, when it comes to raw cannabis extracts, the presence of PPLs can pose downstream processing challenges. These PPLs can congeal and obstruct processing equipment, resulting in costly downtime for cleaning and removal (1).

As a result, the processing of cannabis extracts often includes steps that are aimed to minimize cleaning and removal. Cryoextraction (low temperature extraction with ethanol) and winterization are the two processes normally used to minimize these problems (1). Winterization extraction in cannabis processing is a purification step where undesirable fats, waxes, and lipids are removed from the extracted cannabis oil through cooling, filtration, and solvent removal, resulting in a purer and higher-quality concentrate.

To address this issue, Hudalla described how a liquid chromatography-mass spectrometry (LC–MS) method was developed to quantify specific classes of PPL constituents (1). This enables the optimization of PPL removal across a wide range of pH conditions. By understanding the precise content of PPLs in cannabis oil, operators can tailor degumming processes to effectively remove them, thereby streamlining cannabis extract processing.

Hudalla chose to use a reversed-phase LC–MS method because more information could be uncovered about the chain lengths, the different number of double bonds, and the class of phospholipid (1).

Once the method of choice was selected, Hudalla discussed how they went about finding the reference standards that were used in this experiment as normal certified reference standards could cost “in excess of $30,000” (1). Hudalla and his team overcame this financial obstacle by finding a collaborator who could front them the money, and along with picking representative standards for each class of phospholipids with different chain lengths, the team was able to compile enough reference standards that could be used for quantitation of the residues that the team was examining.

For their study, Hudalla and his team used sunflower oil to look at a spiked sample. After purchasing sunflower oil that was already decommissioned, they spiked it with a 1% mixture of phospholipids (1). Then, they evaluated it in multiple acidic and basic pH conditions, seeing where the phospholipids were ending up. One of the things that the team found interesting was that they did not see the phospholipids in very basic conditions about 12 over 12 pH units in either the aqueous or the oil phase. The question that the team proposed was where the phospholipids went (1). They landed on two theories: 1) the PPLs could have broken down (degraded), or 2) they possibly formed sticky gums, which subsequently stuck to the inside of the laboratory container (1). Utilizing LC–MS analysis to determine PPL composition allowed the team to fine-tune degumming procedures, improving efficiency in the cannabis extract industry.

(1) Hudalla, C. LC–MS Analysis of Phospholipids for the degumming optimization for hemp cannabis extracts. Presented at the Cannabis Science Conference Fall 2023, Providence, Rhode Island, September 22, 2023.

Christopher Hudalla of ProVerde Laboratories Inc. discussed how using liquid chromatography–mass spectrometry (LC–MS) could be used to quantify specific classes of phospholipid (PPL) constituents that can help streamline cannabis extraction.

Using LC–MS to Determine Phospholipid Concentration in Plant-Based Oils

A study written by Guomin Qi, who is affiliated with the College of Chemistry and the Engineering Technology Research Center on Reagent and Instrument for Rapid Detection of Product Quality and Food Safety in Fujian Province, both at Fuzhou University in Fuzhou, China, presents a novel, three-dimensional covalent organic framework (3D-COF) for the purpose of high-performance capture of a marine toxin, okadaic acid (OA) (1).

, the study reviewed the effectiveness of methods such as high performance liquid chromatography (HPLC) and liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS), in terms of both reproducibility and stability, to analyze OA, which is classified as a polyether and polyketide derivative of a C38 fatty acid (1). (And in fact, LC–MS/MS was ultimately used along with a 3D-COF to analyze the toxins identified in this study.) OA is further defined as a lipophilic toxin possessing distributed hydroxyl, polycyclic ether, and carboxyl groups, and may lead to human food poisoning. Covalent organic frameworks (COFs) are considered chemically and architecturally stable, Qi said, and are gaining a reputation as viable sample pretreatment and separation materials because they also offer efficient adsorption, ordered pore distribution, high and specific surface area and low density.

For the experiment authored by Qi, pore-surface engineering was employed to integrate linear building blocks (4,4′-diamino-3,3′-biphenyldiol [BD(OH)

] and benzidine [BD]) with a 3D structural building block backbone (4,4′,4′',4′''-methane-tetrayltetrabenzaldehyde [TFPM]). The ratio of BD(OH)

 was then adjusted to create functional, multicomponent COFs ([OH]

-BD-TFPM) with multiple-mode hydrophobic and hydrophilic groups, where dispersive solid-phase extraction (dSPE) was optimized at x = 25% (1). Essentially, Qi said, this process created content-tunable hydroxyl groups on the pore walls.

Clams and mussels purchased from local markets were the shellfish analyzed in this study. Because OA content in seafood is typically low, an effective pretreatment method has traditionally been sought for high-performance analysis; in this instance, the obtained shellfish muscles were pureed with methanol (MeOH) added into the centrifuge tube, filtered, dried with nitrogen, then redissolved in water and refrigerated (1).

-BD-TFPM COF, coupled with LC–MS/MS, was judged by Qi to be sensitive in the quantitative detection of OA in the clam and mussel samples, and especially so in comparison to previous detection of OA by solid-phase extraction (SPE) materials without hydrophilic interactions; the limit of detection (LOD) in this experiment was established at 0.005 μg/kg (1). Recoveries of OA ranged from 93.9% to 105.1% for the clam samples and 96.7% to 110.2% for the mussels.

Qi compared the robustness of this novel 3D-COF favorably with a previously reported two-dimensional (2D)-COF, particularly in terms of faster adsorption kinetics, better adsorption capacity, and better values for 

, or molal freezing-point depression constant. With a high-performance target capture the end goal of this study, the author concluded that a three-dimensional covalent organic framework SPE was powerful and easy to deploy.

(1) Qi, G. Efficient Capture and Highly Sensitive Analysis of Okadaic Acid by Three-Dimensional Covalent Organic Frameworks with Hydroxyl Surface Engineering. 

Okadaic acid (OA) is considered a marine toxin with distributed hydroxyl, polycyclic ether, and carboxyl groups, easily accumulated in shellfish and known to cause food poisoning in humans.

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