Development of a highly sensitive field-amplified capillary electrophoresis tandem triple quadrupole mass spectrometry for the quantification of trace methamphetamine in sewage

Abstract

Accurate quantification of trace levels of illicit drugs in wastewater, such as methamphetamine (MAMP), is crucial for sewage epidemiology. In this study, we developed a novel method that integrates field-amplified sample injection capillary electrophoresis with triple quadrupole mass spectrometry (FASI-CE-QQQ MS). This method enables simultaneous on-line preconcentration and separation, coupled with highly sensitive detection. Validation demonstrated excellent linearity within the range of 1 to 200 ng/L (R² = 0.9996), a limit of detection (LOD) of 0.1 ng/L (S/N = 12.3), high accuracy (RE < 6.4 %) and precision (RSD < 11.4 %). It was successfully applied to quantify MAMP in two unknown water samples, yielding average concentrations of 3.70 ng/L and 84.73 ng/L, respectively. These results were consistent with those obtained from an interlaboratory comparison exercise across China using on-line solid-phase extraction coupled with ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry (on-line SPE-UHPLC-QQQ MS). Finally, a comprehensive comparison between the newly developed FASI-CE-QQQ MS and the on-line SPE-UHPLC-QQQ MS methods revealed that the FASI-CE-QQQ MS offers significant advantages in terms of sensitivity, rapidity, and reduced solvent and sample consumption, making it a promising approach for the accurate determination of trace drugs in water.