Electroenhanced solid-phase microextraction of methamphetamine with commercial fibers

Abstract

Electroenhanced solid-phase microextraction (EE-SPME) method with gas chromatographic mass spectrometric analysis was investigated for the determination of methamphetamine in urine sample with commercial fibers. In this approach, commercial SPME fibers were used in direct immersion mode with an applied potential to extract methamphetamine. EE-SPME was more effective in the extraction compared to conventional SPME (i.e. application of potential). The method was simple to use, and avoided the need for alkalization and derivatization of methamphetamine. Experimental conditions were optimized to achieve better extraction performance. Various conditions including applied potential, sample pH, extraction and desorption time were investigated. Based on the optimized conditions, EE-SPME achieved a higher enrichment factor of 159-fold than conventional SPME. The calibration plot under the best selected parameters was linear in the range of 0.5–15ng/mL (r=0.9948). The feasibility of EE-SPME was demonstrated by applying it to the analysis of human urine samples. The limit of detection of methamphetamine was 0.25ng/mL with a satisfactory relative standard deviation of 6.12% (n=3) in human urine.