Michael McGinley

A method is illustrated for the simultaneous analysis of ethyl glucuronide and ethyl sulfate in human urine samples.

Increases in vitamin D testing frequency have required more rapid and cost-effective solutions for determining vitamin D levels in plasma. This LC–MS method was adapted for use with core-shell columns to achieve run times of less than 4 min.

Adapting the use of "ultrahigh" performance chromatography for liquid chromatography–mass spectrometry (LC–MS) applications requires specific considerations in integrating the instrument platforms. Mobile phase options are limited to volatile buffers, and slow MS sampling rates can limit throughput advantages that such next-generation media offer. High-throughput LC–MS methods of different relevant pharmaceutical and environmental mixtures were developed using ultrahigh performance core-shell media. Such methods were developed using standard HPLC systems and back pressures, showing the ease and utility of using core-shell media for increasing throughput of LC–MS methods.