Rapid detection and quantification of psychotropic drugs in blood using miniature mass spectrometry

• A novel miniature mass spectrometry approach has been developed for on-site detection and quantification of psychotropic drugs in blood samples. • A simplified liquid-liquid extraction combined with a self-aspiration ESI source was employed to reduce sample and reagent consumption. • The detection of drugs in whole blood achieved good sensitivity and accuracy, with a detection limit of 0.1 ng/mL and a linear correlation coefficient of 0.9999. • The detection results from real blood samples were in agreement with those obtained using the HPLC-MS method, with deviations mostly within 15%. Analysis of psychotropic drugs in blood is a suitable method to assess the effectiveness of patient treatment and the safety of drug dosage. Direct analysis of whole blood using mass spectrometry (MS) faces challenges due to the complex matrix and components in the sample. In this study, we developed a practical analytical strategy based on a miniature MS instrument for on-site detection of psychotropic drugs in blood. In particular, samples were first treated through a simplified and optimized extraction process and then analyzed by a miniature MS mounted with a capillary self-aspirating electrospray ionization source. This method reduced the consumption of samples and reagents while offering high accuracy and sensitivity, with a limit of detection as low as 0.1 ng/mL. We subsequently implemented the detection of venlafaxine and O-desmethyl venlafaxine in some whole blood samples. The results showed good agreement with those obtained by HPLC-MS, demonstrating the accuracy and practicality of the proposed analytical protocol.