| Polluants increased remarkably with the fast increase of population anddevelopment of economy. Organic pollutants attracted the most serious primary focusdue to its high toxicity, hard degradable and bioaccumulative. It is very important forthe envirorunental protection to detect pollutions quickly and precisely. So wedeveloped for different extraction methods of micro-organic pollutants to thedetermination by high-performance liqiud chromatography in three diferentenvironment samples.1. Ionic liquid-based ([BMIM]PF6) microwave-assisted extraction (IL-MAE) wassuccessfully developed for the pretreatment of five organic oxygen pesticides (6-KT,imazethapyr,2,4-D, bensulfuron, uniconazole) to the determination byhigh-performance liquid chromatography (HPLC). Several experimental parametersinfluencing extraction and determination such as the type and concentration of ionicliquids, microwave power, microwave time, microwave temperature, salt effect and thechromatographic conditions were investigated. Under the optimal conditions, limits ofdetections for five analytes were in the range of0.03-0.13μg/mL. The relative standarddeviations at spiking two different concentration levels of2.000μg/mL and20.00μg/mL varied between1.2%-12.5%and3.9%-16.9%(n=6). Two real samplesincluding vineyard soil and orchard soil at two concentration levels were analyzed andrecoveries ranging from76.40%-125.0%and86.20%-117.0%, respectively.2. The IL-MAE method has been developed for extraction and analysis of planthormones from sediment, and the MAE mechanisms were investigated. The influencesof pH of solution on the extrction of plant hormones from sediment were studied. MAE conditions (microwave power, microwave time, microwave temperature) and thevolume of IL were systematically optimized by the mono-factor and orthogonal designtest. Under the optimal conditions, limits of detections for five analytes were in therange of0.008-0.17μg/mL. The relative standard deviations at spiking two differentconcentration levels of1.000μg/mL and10.00μg/mL varied between1.0%-12.0%and1.4%-9.0%(n=6). Real sediment samples at two concentration levels wereanalyzed and recoveries ranging from73.00%-127.0%and66.00%-111.0%,respectively. In addition different samples and objects exhibited different kineticmechanisms in IL-MAE processes. The mechanisms of MAE using ionic liquidssolutions as solvent in the extraction of plant hormones from sediments selected werebased on the typical interface reaction control.3. In this paper,1-octyl-3-methyl imidazole ([C8MIm]Br)-coated Fe3O4magneticnanoparticles (NPs) as an adsorbent of mixed hemimicelles solid-phase extraction wasinvestigated for the preconcentration of five organic contaminants in water samplesprior to HPLC with UV detection. The high surface area and excellent adsorptioncapacity of the Fe3O4NPs after modification with [C8MIm]Br were utilized adequatelyin the SPE process. By the rapid isolation of Fe3O4NPs through placing a strongmagnet on the bottom of beaker, the time-consuming preconcentration process ofloading large volume sample in conventional SPE method with a column can beavoided. A comprehensive study of the adsorption conditions such as the amounts ofFe3O4and C8MIm]Br, the tpye of eluants, elution time and salt effect were alsopresented. Under optimized conditions, five organic contaminants were quantitativelydetermined. The method was then used to determine the five organic contaminants inreal water samples. The accuracy of method was evaluated by recovery measurementson spiked samples. Good recovery results (90.00%-111.0%) were achieved. It isimportant to note that satisfactory preconcentration factors and extraction recoveries forfive organic contaminants were obtained with only a small amount of Fe3O4NPs(0.0300g) and [C8MIm]Br (0.4000g). |
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