The German Beer Purity Law of 1516 makes beer one of the best analyzed food products with the highest standards regarding quality, freshness, appearance, and flavor. According to this law, beer is allowed to contain hops, malt, yeast, and water as ingredients. Of course, beer also contains major B vitamins, bitter substances, and minerals and trace elements (such as Ca, Na, Mg, and Zn) that are important for human nutrition. However, undesirable substances such as pesticides and heavy metals (for instance Cd, Pb, Hg, Sb, and As) can be found as well, mostly as contaminants in brewing water and grains. In particular, the herbicide glyphosate has to be monitored carefully since it is discussed as a possible carcinogenic. The chromatography of glyphosate is challenging because of its high polarity. A well-established method including a derivatization step with 9-fluorenylmethyl chloroformate (FMOC) followed by LC–MS analysis is time-consuming and also susceptible to errors. A sample pretreatment without derivatization is desirable because it is faster and cheaper. A triple quadrupole mass spectrometer optimizes the analytical procedure and establishes a routine method for the analysis of glyphosate in beer. For the determination of low element concentrations, such as As, Se, Pb, Cd, and Zn, inductively coupled plasma-mass spectrometry (ICP-MS) is applied.
Systematic toxicological analysis is an important step in medicolegal investigations of death, poisoning, and drug use. The primary goal is the detection and confirmation of potentially toxic compounds in evidence. This article describes a workflow using nontargeted liquid chromatography–tandem mass spectrometry (LC–MS/MS) for reliable compound identification.
A new method to optimize liquid chromatography (LC) methods using a Quality by Design (QbD) approach is presented. This method is based on the use of design of experiments (DOE) and independent component analysis (ICA) to accurately estimate the modeled responses (that is, the retention times at the beginning, the apex, and the end) of each peak, even for coeluted peaks. This method was applied to the optimization of the separation of nine compounds in a mixture, yielding the design space and the demonstration of robustness of the method.
The pyrolysis–GC–MS method enables direct analysis of solid or liquid polymers without sample pretreatment, as illustrated here for various materials, including a dental filling material and a car wrapping foil.
The presented methods are suitable for the quantification of THC and THCA (and other cannabinoids) in Cannabis sativa and to check THC-free cannabis for compliance.
Direct sample analysis coupled to high-resolution time-of-flight mass spectrometry (TOF-MS) may be effective at analyzing synthetic cathinones, especially for qualitative analysis, because it does not require potentially tedious sample preparation.
Explaining Silyl Ether Formation (SEF) in Supercritical Fluid Chromatography (SFC)
Recent advances in coating techniques and improved polymers employed as gas chromatographic stationary phases have resulted in commercializing low phase ratio capillary column technology with respectable chromatographic efficiency and inertness.
This article reviews how nanomaterials are being used in a variety of sample preparation techniques, such as dispersive solid-phase extraction (dSPE), solid-phase microextraction (SPME), stir-bar sorptive extraction (SBSE), and matrix solid-phase dispersion (MSPD).
Gas chromatography–mass spectrometry (GC–MS) allows isolation and identification of individual analytes within a complex mixture. Helium has traditionally been the first-choice carrier gas, owing to its inertness, performance, and relatively cheap price. Since 2001, however, helium has become increasingly expensive with a reported global increase in price of 500% between 2001 and 2016 (1). In 2012–2013, the global helium shortage increased the number of GC users switching to alternative carrier gases and improved the availability of information on their use.
A look at the current status of detection in ion chromatography, focusing on the most popular detectors in IC: the conductivity detector and the charge detector
The power of nontargeted metabolite profiling is illustrated in a study focused on the determination of molecular markers in malting barley that are predictive of desirable malting quality for brewing applications. The metabolite extraction, detection, and analysis methods are high throughput and reproducible, and therefore, this approach represents a practical addition to the plant breeder’s molecular toolbox.
A look at the current status of detection in ion chromatography, focusing on the most popular detectors in IC: the conductivity detector and the charge detector
The production and sale of counterfeit drugs has risen sharply in recent years. The World Health Organization (WHO) estimates that counterfeit medicines account for approximately 1% of sales in developed countries and well over 10% in developing countries.
Proteins - especially monoclonal antibodies (MABs) - have become increasingly important in pharmaceutical work. However, there are some important differences between conventional, chemically-synthesized drugs and proteins. Because of the complex and weak structure of proteins, even a slight change in conditions, such as pH value, temperature, or mechanical stress, may lead to aggregation and a loss of activity or stability.
This article focuses on the progression that chiral stationary phases (CSPs), specifically developed for HPLC, are currently undergoing because of the pressing need of an easy switch to UHPLC.
The Eastern Analytical Symposium (EAS) will be held this year from November 18 to 20, 2013, in Somerset, New Jersey. EAS is the second largest conference and exposition for laboratory science in the United States dedicated to the needs of analytical chemists and those in the allied sciences.
The article discusses the application of a hybrid organic/inorganic surface technology that forms a barrier between the sample and the metal surfaces of both the HPLC system and chromatographic column. Formed by a vapor deposition of an ethylene-bridged siloxane polymer on metal substrates), this technology effectively addresses common chromatographic challenges such as analyte loss, carryover, and peak tailing due to metal-analyte interactions. It improves peak symmetry and areas, as well as reproducibility, thereby not only benefiting challenging analytes but also increasing confidence in analytical results. We demonstrate the benefits of this technology through the analysis of B-group vitamins, steviol glycosides, and dextran oligosaccharides typically found in food, beverages, and dietary supplements, showcasing its critical role in improving chromatographic performance.