Development of rapid screening methods using solvent microextraction techniques and gas chromatography.

摘要

Sample preparation is often one of the most crucial steps in analytical analysis. In recent years, a great deal of research has been focused on the development of novel sample preparation methods. Microextraction techniques, in which the acceptor phase has a much smaller volume than that of the original sample, have received a great deal of interest in particular. Although solid phase microextraction techniques are well described in the literature, little work has been done on microextraction in the liquid phase. This work describes the application of two new solvent microextraction techniques for the development of screening methods for organochlorine pesticides in river water and for illicit drugs in bio-fluids.; Solvent Microextraction (SME). SME was used as the sample preparation technique in developing a screening method for 11 organochlorine pesticides in river water. This was achieved by optimizing parameters such as extraction time, stir rate, aqueous solution, volume and pH. The screening method was then validated using Gas Chromatography (GC) for separation and further tested using river water samples. This study was extended utilizing fast GC techniques to provide a total screen in 9 minutes.; SME was also used in the development of a screening method for cocaine and its metabolites in urine samples. Extraction parameters were optimized yielding a screen that allowed extraction and separation in 13 minutes at concentrations down to 0.125 mug mL-1.; Hollow Fiber Membrane Solvent Microextraction ( HFMSME). Another microextraction technique, HFMSME was also examined. Screening methods for cocaine and cocaine metabolites in urine and saliva were developed and validated. Extraction from urine samples was achieved in 3 minutes and allowed detection at concentrations below 0.050 mug mL -1. Saliva required longer extraction times of 10 minutes and yielded detection limits of 6 to 28 ng mL-1.