Simultaneous Analysis of Alcohol Metabolites and Barbiturates by LC-MS/MS
This hydrolysis-free method for the simultaneous analysis of alcohol metabolites and barbiturates allows all target analytes to be reported from a single LC-MS/MS method.
Overcoming the Effects of Highly Organic Protein Precipitation Extracts on LC Peak Shape Using Direct Injection
Protein precipitation is frequently used to minimize matrix impact when analyzing biological samples. However, the effects of highly organic protein precipitation sample extracts on LC peak shape can negatively impact accurate quantification. Dilution or further sample preparation steps are often used to minimize these effects; however, here we show that direct injection of sample extracts is a viable option that can be used to prevent peak distortion, while avoiding the time and variability associated with additional sample preparation.
Influencing Selectivity in LC-MS Peptides Analysis on the Raptor ARC-18 Column
Methods for LC-MS peptide analysis often use acidified mobile phases, which can alter retention and selectivity. Here, we demonstrate the effects of modifying acid type, acid concentration, temperature, and gradient slope using several test probes. A Raptor ARC-18 column was employed for this work because it is sterically protected making it extremely stable and resistant to acid damage at low pHs, which is an important characteristic when developing LC-MS methods for peptide analysis.
