Portable fully automated oral fluid extraction device for illegal drugs

Currently used methods for in-field determination of illegal drugs involve various test kits based mainly on the immunoassay technique, where the presence of a compound of interest is assessed by antibody-antigen reaction and manifested by observable color change. Despite being accepted and widely used by police forces to test the presence of illegal drugs in a suspect person, these tests often suffer from unreliable results (high level of false-positive and/or false-negative) due to the cross-reactivity and difficulties with quantification. Therefore, we have developed a portable capillary electrophoresis instrument to determine illegal drugs in oral fluid collected from a suspected person. However, this drug analyzer has still required manual sample preparation. Therefore, this research aimed to develop, test, and validate a fully automated sample pretreatment (purification, extraction, pre-concentration) prototype compatible with the capillary electrophoresis drug of abuse analyzer and suitable for confirmatory analysis by mass spectrometry. The cotton swab from Salivette® oral fluid collector was examined and integrated into the fully automated extractor prototype. The recoveries for the automated extractor were between 18 and 20%, with repeatabilities within 5-11% for 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), cocaine (COC), and cocaethylene (COET). The developed extraction device was easy to use even for unskilled persons, required minimal liquid handling, and was applicable to use in field conditions.