LCGC-North America-10-01-2020

When we are focused on resolving a particular problem, it can be easy to lose sight of important steps in troubleshooting problems with liquid chromatography (LC) instruments. Taking a systematic and disciplined approach to troubleshooting can improve both the efficiency and effectiveness of our troubleshooting efforts.

There’s a lot of interest in moving data to the cloud for security, centralization, and collaboration. Doing so, however, has implications for data integrity and audits. To understand more, we spoke to Monica Cahilly, the president and founder of Green Mountain Quality Assurance, in a podcast interview. Cahilly has more than 25 years of consulting experience, with specialized interest and enthusiasm for data integrity assurance and data governance. A short excerpt of that interview is presented here.

Tobacco-specific nitrosamines are important carcinogens in tobacco products. This article describes a fast, sensitive, selective, and robust method for analysis of these compounds in various tobacco samples by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The separation of analytes from matrix interfering components was performed using a C18 column with simple LC–MS mobile phases. To minimize sample matrix effects on each analyte, a separate internal standard was used for each analyte. Two MS/MS ion pairs were used for each analyte for analyte confirmation and quantification, further enhancing the method’s selectivity and accuracy. The method was validated using different tobacco matrices.

Light scattering detectors are ideally suited for size-exclusion chromatography (SEC) because they provide the molecular weight and radius of gyration information of polymeric samples without column calibration. In this article, the fundamentals of light scattering as applied to SEC are introduced, with emphasis on the origin of the Rayleigh equation. This tutorial is geared to those new to the field or who already utilize light scattering and seek clarification regarding the multitude of equations associated with light scattering. Part X of this series will present a brief summary of commercially available light scattering instrumentation with emphasis on new detector technology. Owing to the complexity of data analysis and the many equations involved with light scattering measurements, part X will also include a glossary of principal symbols and a summary of relevant equations.

When we are focused on resolving a particular problem, it can be easy to lose sight of important steps in troubleshooting problems with liquid chromatography (LC) instruments. Taking a systematic and disciplined approach to troubleshooting can improve both the efficiency and effectiveness of our troubleshooting efforts.

In the present research, similar chromatography fingerprints were obtained using finely-tuned cryogenic-modulation (CM) and flow-modulation (FM) comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS) experimental conditions.

The Eastern Analytical Symposium has gone virtual for 2020, making it easy for everyone to attend. We highlight a few of the talks and innovative sessions that you won’t want to miss.