Application of dispersive liquid-liquid microextraction and CE with UV detection for the chiral separation and determination of the multiple illicit drugs on forensic samples

作者：Meng Liang; Wang Bin; Luo Feng; Shen Guijun^*; Wang Zhengqiao; Guo Ming

来源：Forensic Science International, 2011, 209(1-3): 42-47.

DOI：10.1016/j.forsciint.2010.12.003

• Dispersive liquid-liquid microextraction
• Illicit drugs
• Capillary electrophoresis
• Chiral separation
• Forensic science

A new method was developed for pre-concentration, chiral separation and determination of multiple illicit drugs on forensic samples using dispersive liquid-liquid microextraction (DLLME) and capillary electrophoresis (CE) with Ultra Violet (UV) detection. The method was based on the formation of tiny droplets of an organic extractant in the prepared sample solution using water-immiscible organic solvent (chloroform) dissolved in water-miscible organic dispersive solvent (isopropyl alcohol). The organic phase, which extracted heroin, DL-methamphetamine, DL-3, 4-methylenedioxymethamphetamine and DL-ketamine from the prepared sample solution, was separated by centrifuging. The sedimented phase was transferred into a small volume CE auto-sampler vial with 10 mu L of 1% HCl methanol solution and evaporated to dryness. The residue was reconstituted in lidocaine hydrochloride aqueous solution (internal standard) and introduced by electrokinetic injection into CE. Parameters affecting extraction efficiency were investigated and optimized. Under optimum conditions, linearity of the method was 0.15-6500 mu g/L for all target analytes. The LODs (S/N = 3) were 0.05-0.20 mu g/L. Excellent repeatability (RSD <= 4.4%, n = 5) was achieved. The feasibility of this method was demonstrated by analyzing spiked forensic samples. To our knowledge, it is the first time to combine DLLME with CE for chiral separation and determining illicit drugs on forensic samples.

• 出版日期2011-6-15
• 单位大连大学; 司法部司法鉴定科学技术研究所; 中国人民公安大学