Innovative disposable pipette extraction for concurrent analysis of fourteen psychoactive substances in drug users' sweat.

• Determination of psychoactive substances in sweat samples. • Extraction of psychoactive substances using disposable pipette extraction and GC–MS. • Analysis of psychoactive substances in sweat samples collected from drug users. Widespread consumption of drugs of abuse worldwide has caused concern: it adversely affects public health, individual safety, and social structures. Experts are particularly alarmed because new psychoactive substances have been increasingly detected in biological samples. In recent years, several studies have focused on developing methods to identify psychoactive substances in alternative biological matrices, such as sweat. This approach holds promise for monitoring substance use, especially in individuals undergoing rehabilitation. Among the commonly employed analytical procedures, extraction using disposable DPX tips stands out as a novel, miniaturized, and promising technique. This study aimed to validate and to apply a method to analyze various substances, including amphetamine, methamphetamine, MDMA, MDA, MDEA, cocaine, cocaethylene, anhydroecgonine methyl ester, dibutylone, N-ethylpentylone, 25E-NBOMe, 25C NBOMe, 2C C, 2C-E, fentanyl, and carfentanil, in sweat samples simultaneously. In this method, sweat is collected by using laboratory-developed patches, and extraction is conducted with DPX-SCX tips. Gas chromatography coupled to mass spectrometry is employed to separate, to identify, and to quantify the analytes. Validation results indicated that the quantification limit ranged from 2 to 30 ng of analyte/patch, and that the method was linear for analyte concentrations ranging from 2 to 1100 ng/patch. The validated method was applied to analyze 30 sweat samples collected from volunteers drug users and processed by using both the selected ion mode (SIM) and full scan. The method was able to detect and to quantify substances such as cocaine, cocaethylene, anhydroecgonine methyl ester, MDMA, MDA, nicotine, cotinine, caffeine, procaine, lidocaine, and ethylamphetamine simultaneously. The recovery rates ranged from 72.4 % to 97.1 %. The analytes were stable in the biological matrix. In conclusion, the validated method proved effective and allowed the target analytes to be quantified in sweat samples, highlighting that sweat is a viable matrix for analyzing drugs of abuse. [ABSTRACT FROM AUTHOR]