Rapid screening and semi-quantitative analysis for forensic drugs in blood using liquid chromatography triple quadrupole mass spectrometry

Determination of drugs in whole blood is often necessary in forensic analysis because of the difficulty in obtaining serum or plasma. Conventional procedures to analyze drugs in complex matrices like whole blood involve tedious, time consuming, expensive, and complex steps, and possible sample loss and contamination problems are not unusual. QuEChERS is a sample preparation technique that was developed for the extraction of multi-class pesticide residue from fruits and vegetables, in 2003.
In this study, we report a modified QuEChERS extraction method for pretreatment in forensic analysis and a simple quantitative method including information of calibration curve of each compound by high-speed triple quadrupole mass spectrometry. To achieve a highly specific and sensitive detection in screening and quantitation a MRM triggered product ion scanning method using a fast polarity switching speed and a fast scan speed was applied to 108 components including illicit drugs, psychotropics, hypnotics, pesticides and other substances. As the MRM acquisition time was very fast, this enabled product ion spectra to be generated in both positive and negative ionization mode which could be matched against a user library of compounds as an automated aid to screening and compound identification.
The combination of the modified QuEChERS extraction method and high-speed triple quadrupole LC/MS/MS with a simple quantitative method enable to acquire reliable data easily.