Abstract
The quadrupole mass spectrometer is used for quantitative determination of drug concentrations in biological matrices because it has high selectivity. Though the use of high-performance liquid chromatography/tandem mass spectrometry makes it possible to conduct highly-sensitive determinations at the picogram level, sample pretreatment is essential for the removal of endogenous substances from matrices and to facilitate ionization of the drug substance. Appropriate sample pretreatment ensures avoidance of a decline in sensitivity and improves reproducibility. This commentary provides a discussion on the development of appropriate sample treatment, including cautionary points related to sample treatment procedures, and an explanation of methods for treating a variety of matrices, such as protein precipitation, liquid-liquid extraction, and solid-phase extraction.
