Application Of Miniaturization Liquid Liquid Extraction For The Analysis Of Trace Pollutants In Environmental Water Samples

Pretreatment of the samples is necessary because of the trace level of analytes in environment. Liquid liquid extraction (LLE) is the classical method of the samples pretreatment for the determination of environmental pollutants, but it consumes time and labor and requires large volume of toxic organic solvents, which has a great threaten on human health and environmental protection. Therefore, pretreatment methods of effective, fast, less or free organic solvent are attracting more attention. Liquid phase microextraction (LPME) and cloud point extraction (CPE) are miniaturized pretreatment techniques which developed from LLE.In order to establish methods of simple, effective and fast to separate the odorous compounds and heavy metal ions, LPME and CPE were chosen as the pretreatment methods in this study.(1) LPME combined with gas chromatography/mass spectrometry (GC/MS) was used to detect the two odorous compounds (GSM and MIB which are short for geosmin and 2-methylisoborneol) of environmental water samples. Comparison on the optimized conditions of headspace-liquid phase microextrction (HS-LPME) and single drop microextraction (SDME), HS-LPME was chosen as the pretreatment technique for the further study. HS-LPME-GC/MS was successfully used for the determination of GSM and MIB in the real water samples.(2) Dispersive liquid liquid microextrction (DLLME)-back extraction combined with capillary zone electrophoresis (CZE) was used to determine Hg²⁺ in environmental water samples. The conditions of the CZE separation and the factors influencing the efficiency of chelate reaction, DLLME and back extraction were studied and the optimized experimental conditions were used for the analysis of Hg²⁺ in environmental water samples.(3) Cloud point extraction (CPE) combined with ultraviolet-visible absorption spectroscopy (UV-Vis) was used to determine Hg²⁺ in water samples. After studying the factors influencing the CPE efficiency and UV-Vis detection, the optimized conditions were successfully used in real water samples.