Determination Of Organic Pollutants In Environmental Water By Ultrasonication Assisted Dispersive Liquid-liquid Microextraction Coupled With HPLC

Dispersive liquid-liquid microextraction (DLLME) developed in2006was a new liquid-liquid extraction mode of microextraction. The advantages of DLLME method were low cost, rapidity, simplicity of operation, high enrichment factor and recovery as well as favorable compatibility of extraction phase with subsequent instrumental detection methods such as High performance liquid chromatography (HPLC), Gas chromatography (GC), Flame atomic absorption spectrometry (FAAS) etc. DLLME has been applied to extract and separate trace inorganic metallic ions and organic compounds in environmental samples, foods, biological samples and minerals etc. DLLME was an environment friendly technique and has become more and more popular among sample preparation. In this thesis, a novel method for the enrichment and determination of trace organic matters in environmental water by UA-DLLME combined with HPLC was used. The thesis consists of four parts:(1) Several common preconcentration techniques were introduced. And it focused on a new mode of liquid-liquid microextracion——DLLME.(2) UA-DLLME was used for the enrichment and determination of trace dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DOP) in environmental water. Experimental conditions of chromatographic separation and DLLME such as species and volume of extractants and disperser solvents, the ultrasonic microextraction time and ionic strength were examined. Under the optimized conditions, the chromatographic peak area was proportional to their individual concentration in1.00-100μg·L-1with relative coefficients more than0.996. The average recoveries were91.10%-103.3%and the relative standard deviations (RSD) were2.01%～6.76%(n=5) for the spiked water with20.0μg· L-1. The limits of detection were0.08μg·L-1,0.04μg·L-1,0.03μg·L-1,0.01μg·L-1and0.07μg·L-1, respectively. This method was applied to the enrichment and determination of5phthalates in the water samples from the Yellow River and in the influent and the effluent from local wastewater-treatment plant. The average recoveries were85.45%～119.4%with RSD of2.28%-11.14%(n=3). (3) UA-DLLME was used for the enrichment and determination of trace naphthalene (NT), anthracene (AN) and fluoranthene (FT) in environmental water. Experimental conditions of chromatographic separation and DLLME such as species and volume of extractants and disperser solvents, the ultrasonic microextraction time and ionic strength were examined. Under the optimized conditions, the chromatographic peak area was proportional to their individual concentration in0.10-10.0μg·L-1with relative coefficients more than0.998. The average recoveries were91.20%～104.4%and the RSD were2.59%～6.45%(n=5) for the spiked water with0.50μg·L-1. The limits of detection were10.3×10-3μg·L-1、1.13×10-3μg·L-1and6.76×10-3μg·L-1, respectively. This method was applied to the enrichment and determination of3polycyclic arom hydrocarbons (PAHs) in the water samples from the Yellow River and in the influent and the domestic wastewater. The average recoveries were84.00%～106.79%with RSD of6.52%～12.79%(n=3).(4) UA-DLLME was used for the enrichment and determination of trace benzene, toluene and ethylbenzene in environmental water. Experimental conditions of chromatographic separation and DLLME such as species and volume of extractants and disperser solvents, the ultrasonic microextraction time and ionic strength were examined. Under the optimized conditions, the chromatographic peak area was proportional to their individual concentration in5.00-100μg·L-1with relative coefficients more than0.995. The average recoveries were91.44%～104.8%and the RSD were4.23%-8.02%(n=5) for the spiked water with20.0μg·L-1. The limits of detection were0.47μg·L-1、0.17μg·L-1and0.14μg·L-1, respectively. This method was applied to the enrichment and determination of benzene, toluene and ethylbenzene in the water samples from the Yellow River and in the influent and the the domestic wastewater. The average recoveries were91.32%～114.88%with RSD of5.14%～10.55%(n=3).