Application Of Novel Sample Pretreatment In Organic Pollutants Analysis

With the increasing concern on the environment and food safety, the development of environmentally and more efficient sample pretreatment technique would therefore be of great value. Liquid-phase microextraction (LPME) and solid phase microextraction(SPME) were novel sample pretreatment technique, which are faster and more environmentally friendly than traditional extraction methods. I focused on the development of new environmentally friendly method for organic pollutants pretreatment, and the work was summarized as follows:Low-density solvent-based dispersive liquid-liquid microextraction was developed for determining trace levels of17organochlorine pesticides in snow. The optimized conditions yielded a good performance, with enrichment factors ranging from271to474and recoveries ranging from71.4%to114.5%and relative standard deviations between1.6%and14.8%. The detection limits, calculated as3×the signal-to-noise ratio, ranged from0.02to0.11μg L-1. The validated method was used to successfully analyze17analytes in snow water samples, overcoming the drawbacks of some existing low density solvent liquid microextraction methods, which require special devices, large volumes of organic solvents or complicated operation procedures.Ultrasound-assisted liquid phase microextraction, combined with a novel solvent layering technique, was developed for extraction of organochlorine pesticides from soil. Under optimal conditions, recoveries ranged from71.6%to114.6%and correlation coefficients ranged from0.9961to0.9996. Detection limits, calculated as3×signal-to-noise ratio, were from0.04to0.18μg L-1. The standard deviations ranged from6.7%to19.6%.A simple, rapid, efficient and environment friendly pretreatment method combined with liquid chromatography coupled to mass spectrometry to detect enantiomers of chiral pesticides as triadimefon and triadimenol in beer samples using supramolecular solvent-based microextraction. Under the optimized conditions, recoveries ranging from84%to100%and relative standard deviations between1.6%and5.7%. The detection limits ranged from0.22to0.98μg L-1Compared supramolecular solvent with traditional solvents in the same conditions, extraction capability of supramolecular solvent was obviously higher than other solvents. The validated method was used to successfully analyze enantiomers of triadimefon and triadimenol in beer samples.Nitrogen flush assisted micro-solid phase extraction using special extraction devices was developed for the analysis of volatile organic pollutants in environmental water samples. Recoveries were ranging from77.9%to91.4%and relative standard deviations between6.9%and10.4%. The detection limits ranged from0.008to0.023μg L-1.