Trace Organic Pollutants In Water(Sediment) Been Studied By New Extraction Techniques

Recent long-term environmental water(sediment) monitoring studies have demonstrated a drastic increase in concentrations of organic pollutants over the past decade. Therefore, the analysis and research of the organic pollutant residues in environmental analytical chemistry is of great significance. However, most instruments cannot handle complex sample directly, as a result, a sample extraction step is critical and takes up a major portion of the total analysis time. The ideal extraction techniques should be simple, automatic, rapid and efficient. So, the current research is mainly focused on the development of four new rapid and efficient extraction techniques.1. An ionic liquid/salt aqueous two-phase system(IL-ATPS) procedure was evaluated for simultaneous extraction and determination of herbicides(2, 4-dichlorophenoxy acetic acid, bensulfuron) and plant growth regulators(kinetin, 6-benzylaminopurine, uniconazole) in sediment followed by high-performance liquid chromatography(HPLC) with the diode array detector(DAD). The effects of experimental parameters on IL-ATPS procedure including the volume of IL, pH, the extraction temperature and the amount of salt were evaluated. Under the optimum conditions, the limits of detection(LODs) were in the range of 0.001-0.0004 μg/g for IL-ATPS. Relative standard deviations(RSDs, n=5) and recoveries were in the range of 2.4-4.3% and 95-98%, respectively for IL-ATPS except for bensulfuron. The recoveries obtained by means of IL-ATPS were higher than that by means of other methods, which was applied to the simultaneous determination of the above five target analytes in actual sediment sample.2. Dispersive liquid-liquid microextraction procedure based on solidification of floating organic droplet(DLLME-SFO) has been investigated for determination of fungicides(Cyprodinil, Difenoconazole, Myclobutanil and Spiroxamine) in the sediment by high performance liquid chromatography-diode array detection(HPLC-DAD). Due to extraction solvents can be separated easily and sample solution, the experiment time can be shortened in the overall extraction process. Several parameters(the type of the extraction solvent and its volume, the type of dispersive solvent and its volume, centrifugal speed, extraction time and salt effect) affecting the extraction efficiencies of target fungicides were studied and optimized. Under the optimized conditions, the limits of detections(LODs) for the target analytes were in the range of 0.1-0.5 μg/g. And satisfactory recoveries of the target analytes in the sediment samples were 81-99%, with relative standard deviations(RSD, n=5) that ranged from 1.8 to 6.5%. Finally, this simple, sensitive and environmentally friendly method was successfully applied to determine the target fungicides in actual sediment samples.3. Magnetic solid-phase extraction(MSPE)( magnetic CA(mCA) material as sorbent) technique has been investigated for determination of plant growth regulators(PGRs)(kinetin(6-KT), 6-benzylaminopurine(6-BA), 2, 4-dichlorophenoxy acetic acid(2,4-D) and uniconazole(UN)) in the environmental water samples by high performance liquid chromatography-diode array detection(HPLC-DAD). Several experimental parameters of one method including the amount of sorbent, extraction time, pH, salt concentration and desorption conditions were studied. Under the optimized conditions, one extraction method provided high recoveries(89-101%), low the limits of detection(0.01-0.2 μg/L) and satisfactory analytical features in terms of precision(RSD 1.7-5.1%, n=5). The method was applied to the analysis of the PGRs in environmental water samples with satisfactory result.4. The carbon aerogels/ionic liquid/polydimethylsiloxane solid-phase micro-extraction composite coating was prepared, and the material was used as coating of solid phase microextraction and then extracted plant growth regulator and fungicides in reservoir water. Moreover, several parameters affecting the extraction efficiency such as the amounts of Ionic liquid, coating thickness, extraction temperature, the types of desorption solvent, extraction time and have been investigated. Under the optimum conditions, satisfactory recoveries for the target analytes were in the range of 86.00-101.0% with 2.6-11.4% relative standard deviations(RSD, n=6). The method was applied to the analysis of the plant growth regulator and fungicides in water samples with satisfactory result.