| In the chromatographic analytical process, sample pre treatment is employed inorder to avoid the interference, improve the sensitivity, insure the accuracy of theresults. Therefore, in the analysis of the analytes with low concentration in thecomplicated sample matrices, the sample pre treatment process is essential. With theadvances of the analytical technology, environmentally friendly, inexpensive, andefficient sample pre treatment technology has addressed widespread attention andrecognition. As a new separation and enrichment method, cloud point extraction hasbeen widely used in the analysis of organic pollutants for its simple operation, lowenvironmental toxicity, high extraction efficiency and easy to combine with highperformance liquid chromatography, flow injection analysis and capillaryelectrophoresis. Carbamate pesticides, phthalates and aromatic amines are organicpollutants in the environment and more and more attention has been paid to theireffects on human health and the environment. The analysis of organic pollutants isdifficult because of their low concentrations in environmental samples andcomplicated matrices. In this paper, we develop a method for determination of organicpollutants in environment water and vegetables by cloud point extraction coupledwith high performance liquid chromatography.A method of cloud point extraetion coupled with high performance liquidchromatography has been successfully used to determine four analytes in vegetables,i.e., carbaryl, pirimicarb, dimethyl phthalate and diethyl phthalate. The readilybiodegradable nonionic surfactant Tergitol15S7has been selected as the extractionsolvent. The optimized liquid chromatography conditions are as follows: theoptimized mobile phase is methanol–water (70:30, v/v), the flow rate is maintained at0.6mL/min, the column temperature is set at35℃, and the UV absorbance detection is set to230nm. To obtain optimum extraction efficiency, several experimentalparameters including surfactant concentration, salt concentration, equilibrationtemperature, equilibration time, and sample pH are identified. Under the optimumconditions, the linear regression coefficients of the standard curves are greater than0.9984. The limits of detection for carbaryl, pirimicarb, dimethyl phthalate anddiethyl phthalate are0.003,0.015,0.012, and0.006ug/mL, respectively. Theintra day and inter day relative standard deviations are less than5.75%and6.97%.This method has been applied to the determination of carbamate pesticides andphthalates in vegetables, giving recoveries from78.3%to111.6%.The cloud point extraetion coupled with high performance liquid chromatographyhas also been applied to the determination of p nitroaniline, m nitroaniline ando nitroaniline in water sample. The optimum extraction conditions are as follows:surfactant concentration2%(v/v); salt concentration0.7mol/L; equilibriumtemperature35℃; equilibrium time15min. The intra day and inter day relativestandard deviations are less than3.10%and6.54%. Recoveries are from80.5%to110.5%. The proposed method has been proven to be an efficient, green, rapid, andinexpensive approach for extraction and determination of target analytes present inenvironment water and vegetables samples. |
