Simple segmental hair analysis for α-pyrrolidinophenone-type designer drugs by MonoSpin extraction for evaluation of abuse history

For detection of a history of drug abused, we developed a simple method for extracting pyrrolidinophenone-type designer drugs in human hair by using a MonoSpin® C18 column. Target drugs were extracted from a single alkaline-digested hair segment (length, 10 mm; weight, ca 0.1 mg). The analytes extracted were then analyzed by high-performance liquid chromatography–mass spectrometry without evaporation of the eluent after MonoSpin extraction. Linearity from 0.5 to 500 ng/mg was observed for all the tested drugs using an internal standard method (correlation coefficients >0.998) and the limit of detection was 0.2 ng/mg. The recoveries were between 0.7 and 11.1%. The coefficients for intraday and interday variations at 4, 40, 200, and 400 ng/mg in hair were between 0.7 and 11.1%. This method was successfully applied to the identification of these designer drugs in segmented human hair from drug abusers and indicated their history of drug abuse. The results were consistent with the patients’ statements, indicating that this rapid method can be used to detect a history of drug abuse.