Best Practices in Biological Sample Preparation for LC‐MS Bioanalysis

This chapter reviews the most commonly used sample preparation techniques in the pharmaceutical and biopharmaceutical industry for liquid chromatography coupled with mass spectrometry (LC-MS) or tandem mass spectrometry (LC-MS/MS) bioanalyses. The chapter primarily talks about protein precipitation (PPT), liquid-liquid extraction (LLE), and solid phase extraction (SPE), focusing on the need for balancing extraction recovery and assay selectivity, and on the operational details of each technique. It explains the specificity, advantages, limitations and applications of each technique. In addition, some non-routine sample preparation techniques are discussed. It is important for bioanalytical scientists to understand the physicochemical properties (e.g. pKa, log P and log D, etc.) of the analyte(s) of interest and other needs of the intended study in order to select the most appropriate sample preparation procedures. Since 96-well plates are the most popular sample preparation format in LC-MS bioanalysis, all examples given in the chapter assume this format is used unless otherwise stated.