| In order to get accurate date and good reproducibillity in chemical analysis, it is necessary to make sample preparation for some matrix complex, low concentration samples. It is usually crucial to the success of the samples analysis, especially embodied in the analysis of organic compouned. Therefore, the rapid, simple, easy to automation sample preparation technique has become one of the important research direction for analytical chemistry workers.Liquid-phase microextraction, as a sample preparation technology, was developed in recent years. It is a new environmental benign sample preparation technique which incorporates sampling, extraction and concentration into a single step and makes uses of only a small amount of solvent for concentrating analytes from aqueous samples. Recent years, ionic liquids as "green solvent" have been widely used in separation and extraction process. The traditional sovent has disadvanges of strong volatile, high toxic, serious damage to the environment, etc. Using ionic liquids instead of organic solvent can overcome the shortcomings from the source. Meanwhile ionic liquids have the selected dissoluting ability for water, organic solvent and other materials through adjusting their structures.On the basis of previous work, this paper used ionic liquid instead of organic solvent combing cold-induced aggregation dispersive liquid-liquid microextraction technology to determine organic pollutants in water samples. It's main content are as follows:1. A novel cold-induced aggregation dispersive liquid-liquid microextraction with [C4MIM]PF6 as extractant has been developed for the determination of benzoic acid in water samples by high-performance liquid chromatography with ultraviolet detection. The extraction was performed under the condition of [C4MIM]PF6 volume 50μL, dispersive solvent(acetonitrile) volume 0.5 mL, pH 3, solution temperature 55℃, extraction time 4 min, centrifugation time 9 min. Under this optimum condition, the concentration factor was 116, linear range was between 1 to 500 ng mL-1, the limit of detection was 0.6 ng mL-1 and relative standard deviation was 5.1%. Water sample including tap water, lake water and river water were analyzed by the proposed procedure and the spiked relative recoveries were in the range of 90.9%-99.3%.2. A novel cold-induced aggregation dispersive liquid-liquid microextraction has been developed for the determination of phthalate esters in water samples by high-performance liquid chromatography with ultraviolet detection. The extraction was performed under the condition of extraction solvet ([C8MIM]PF6) volume 32μL, dispersive solvent (acetonitrile) volume 0.75 mL, solution temperature 50℃, extraction time 3 min, no salt added. Under this optimum condition, the concentration factors were 174-212, linear range was 2-100 ng mL-1, the limits of detection were 0.68-1.36 ng mL-1 and relative standard deviation was 2.2%-3.7%. Water sample including tap water, bottled mineral water and river water were analyzed by the proposed procedure and the spiked relative recoveries were in the range of 90.1%-99.2%.3. A novel cold-induced aggregation dispersive liquid-liquid microextraction with [C8MIM]PF6 as extractant has been developed for the determination of phenolic compounds in water samples by high-performance liquid chromatography with ultraviolet detection. The extraction was performed under the condition of [C8MIM]PF6 volume 35μL, dispersive solvent (acetone) volume 1.0 mL, solution temperature 60℃, extraction time 3 min. Under this optimum condition, the concentration factors were 112-168, linear range was 1.5-200 ng mL-1, the limits of detection were 0.58-0.86 ng mL-1 and relative standard deviation was 2.3%-4.1%. Water sample including tap water, lake water and river water were analyzed by the proposed procedure and the spiked relative recoveries were in the range of 97.1%-108.1%. |
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