Degassing-Filter Caps and Helium Sparging
The answer to the following reader question about degassing mobile phase solvents was supplied by LCGC's "LC Troubleshooting" columnist John Dolan.
The answer to the following reader question about degassing mobile phase solvents was supplied by LCGC’s “LC Troubleshooting” columnist John Dolan.
Q: Just how good of a job do degasser–filter caps do on degassing HPLC solvent? Where can I find a technique or protocol to degas solvent with helium?
John Dolan: I have not seen data on the effectiveness of the caps, but I suspect that if you use them with a vacuum filtration device, they should be similar to vacuum degassing, which usually is adequate. Helium sparging is simple — just use a sparging frit (a solvent reservoir frit is fine) on the helium line — and bubble a stream of helium (for example, use 5 psi pressure) through the solvent for 4–5 min. Usually this is enough to keep the solvent degassed for a day. In difficult cases, or where any oxygen causes problems (for example, with reductive electrochemical detection), continuous sparging may be necessary. Just turn down the flow to a trickle to keep the solvent degassed. Most popular today are the in-line vacuum degassing systems, which are quite effective, but they might not remove sufficient oxygen for oxygen-sensitive methods.
Analyzing Bone Proteins in Forensic Laboratories Using LC−MS/MS
November 4th 2024A recent study compared different workflows for extracting, purifying, and analyzing bone proteins using liquid chromatography with tandem mass spectrometry (LC–MS/MS), including an in-StageTip protocol previously optimized for forensic applications, and two protocols using novel suspension-trap technology (S-Trap) and different lysis solutions. LCGC International discussed this work with Noemi Procopio of the School of Law and Policing and the Research Centre for Field Archaeology and Forensic Taphonomy at the University of Central Lancashire (UK), corresponding author of the paper that resulted from this study.
AI and GenAI Applications to Help Optimize Purification and Yield of Antibodies From Plasma
October 31st 2024Deriving antibodies from plasma products involves several steps, typically starting from the collection of plasma and ending with the purification of the desired antibodies. These are: plasma collection; plasma pooling; fractionation; antibody purification; concentration and formulation; quality control; and packaging and storage. This process results in a purified antibody product that can be used for therapeutic purposes, diagnostic tests, or research. Each step is critical to ensure the safety, efficacy, and quality of the final product. Applications of AI/GenAI in many of these steps can significantly help in the optimization of purification and yield of the desired antibodies. Some specific use-cases are: selecting and optimizing plasma units for optimized plasma pooling; GenAI solution for enterprise search on internal knowledge portal; analysing and optimizing production batch profitability, inventory, yields; monitoring production batch key performance indicators for outlier identification; monitoring production equipment to predict maintenance events; and reducing quality control laboratory testing turnaround time.
Profiling Volatile Organic Compounds in Whisky with GC×GC–MS
November 1st 2024Researchers from Austria, Greece, and Italy conducted a study to analyze volatile organic compounds (VOCs) present in Irish and Scotch whiskys using solid-phase microextraction (SPME) Arrow with comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC–MS) to examine the organoleptic characteristics that influence the taste of spirits.
