QuEChERS sample preparation prior to LC-MS/MS determination of opiates, amphetamines, and cocaine metabolites in whole blood.

Modern LC-MS/MS instruments have sensitivity and scanning velocity high enough to analyze many different compounds in single runs. Consequently, the sample preparation procedure has become the bottleneck for developing efficient, rapid, and cheap multi-compound methods. Here, we examined one-step sample preparation based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) salts to set up and validate a LC-MS/MS method for the simultaneous determination of 35 drugs of abuse and their metabolites in whole blood. Despite large differences in physicochemical properties, this simplified QuEChERS extraction method yielded satisfactory recoveries (until 96%) for the 35 molecules. The amounts of QuEChERS salts had no influence on extraction yield. Chromatographic separation was obtained in less than 6 min. LLOD and LLOQ were 3 and 5 ng/mL, respectively. The procedure was successfully validated and then applied to 253 cases of driving under the influence of drugs (DUID), collected over a 6-month period.