Rapid Identification of Illicit Drugs Using Portable Thermal Desorption – Electrospray Ionization (TD-ESI) Ion Trap – Mass Spectrometry (IT-MS) with Two-Step Scanning

Abstract

With the increasing prevalence of illicit drugs, social security and human health are at serious risk. However, traditional detection techniques require a lengthy pretreatment process to eliminate matrix interference and do not allow rapid, in situ analysis. Ambient ionization is a powerful tool for the rapid determination of illicit drugs in different matrices because it usually eliminates the need for sample pretreatment, and the portable mass spectrometer brings convenience to in situ detection. This study employed a thermal desorption-electrospray ionization (TD-ESI) source combined with a portable mass spectrometer to rapidly characterize illicit drugs in drinks, instant powders, and solid food surfaces. Air was utilized instead of nitrogen as the carrier gas for TD-ESI/MS in order to save space and cost together with rapid on-site analysis. A full-scan waveform combined with a qualitative pre-scan waveform (QPSW) was employed to form a two-step scanning mode to accurately identify the drugs. The results showed that the limits of detection (LODs) for the analytes were 100–200 ppb in drinks, 700–1000 ppb in instant powders, and 1 ng/cm2 on solid food surfaces. The complete TD-ESI/MS analysis time was less than 1 min.