影像测量法辅助电喷雾萃取电离源喷头的研制

电喷雾萃取电离(EESI)源具有无需样品复杂预处理、易于集成和小型化、适于现场分析等特点,是近年来研究的热点。喷头孔是影响EESI源性能的关键部件。然而,因喷头孔几何参数非常小,使用常规方法无法对其进行精确地检测与评估,一直无法满足EESI源的要求。本工作开发了一种基于影像测量的检测与评估方法,通过提取喷头孔的几何轮廓坐标参数,对比分析两种工艺制造的喷头孔的直径与圆度误差。在优化仪器参数的条件下,采用新工艺制造的EESI源对甲基苯丙胺进行检测,检出限从0.101μg/L降至0.041 7μg/L,RSD从0.9%~5.8%降至0.6%~4.2%,实验结果与采用影像测量法的评估结果一致。采用新工艺制造的EESI源对尿液中的可待因、海洛因、氯胺酮、苯丙胺、咖啡因、麻黄碱、甲基苯丙胺、地西泮、戊巴比妥和舒乐安定进行连续5日检测,各样品的最大RSD均小于5.2%。结果表明,该影像测量法可缩短EESI源研制周期、降低成本,EESI源的稳定性与灵敏度可得到较大提高。

Development of a High-Performance Imaging-Aided Extractive Electrospray Ionization Sprayer

Extractive electrospray ionization (EESI) source has become a hot research topic in recent years owing to its many advantages, such as no need of complicated sample pretreatment, ease of integration and miniaturization, the ability of on-site analysis, etc. Sprayer hole is one of the most important parameters affecting EESI source’s performance. However, since the geometric scale of sprayer hole is very small, the performance of EESI source is difficult to be optimized using conventional methods. In this study, a high-performance optical imaging method was developed to improve the spray efficiency of EESI source, which is very useful to detect and evaluate the coordinates of the sprayer holes geometric contours. Through comparing the diameter and roundness error of the sprayer holes made by the traditional and our new approaches, the optimized instrument parameters were obtained and examined. Under the optimized conditions using the EESI source manufactured through the new technology, the detection limit of methamphetamine was remarkably improved from 0.101 μg/L to 0.041 7 μg/L, and the RSD decreased to 0.6%-4.2% from 0.9%-5.8%. The experimental results are consistent with that obtained using the image measurement method. For the EESI source manufactured using the new technology, more compounds of wide interest, such as codeine, heroin, ketamine, benzedrine, caffeine, ephedrine, methamphetamine, diazepam, pentobarbital, and estazolam in urine, were used in test experiments for five consecutive days. The maximum RSD for these samples was less than 5.2%. The results show that the new technology makes the EESI source much more stable and sensitive, and more suitable for the application of EESI sources in commercial settings. The imaging aided method has advantages of simple operation, which can reduce time and cost for the development of a high performance EESI source.