| Food is the material basis for human survival and development, food safety relationship between the world's people's lives, and now some people in order to seek their own interests, they add to a lot of some harmful chemical composition in the food, so the analysis of harmful ingredients in food is necessary. More than 80% of analysis time is spent on sample collection and sample preparation, so sample preparation is a critical part of the analytical process. In analytical chemistry, the commonly used method of sample separation and preconcentration is dispersive liquid-liquid microextraction and solid phase extraction method, In recent years, in the extraction experiments, analytical chemists in order to make the experiment less time-consuming, simple operation, low cost, green environmental protection has paid a hard effort. In this paper, Based on dispersive liquid-liquid microextraction and magnetic solid phase extraction, the ability of ILs and magnetic nanomaterials as extractant for the pigment and herbicide in food was studied, in the same, fluorescence spectrophotometer, UV-visible spectro Photometry, High performance liquid chromatography was used to determinated. Contents is as follows:1. We introduced the principle of liquid liquid microextraction and magnetic solid phase extraction methods, and reviewed the dispersion liquid liquid micro extraction has advantages and disadvantages of several extraction methods, and structure of the magnetic materials, its synthetic methods, characterization and the application research of modified magnetic materials and the application of the magnetic materials.2. A new method was developed to determinate the erythrosine in candy and tomato sauce using in-situ ionic liquid formation liquid-liquid microextraction?ISILF–LLME? followed by fluorescence detection. In this experiment, a little amount of the KPF6?as an ion-pairing agent? was the sample solution containing small number of the [C8MIM][Br]?as hydrophilic ionic liquid?. The fine droplets of 1-octyl-3-methylimidazolium hexafluorophosphate [C8MIM][PF6] was formed and a cloudy solution was obtained. The main factors influencing the extraction efficiency of ISILF –LLME including the selection of IL, amount of KPF6, solution pH, the extraction time, and centrifugation time, were optimized. The effect of other synthetic food colorants for determination of erythrosine was evacuated. Under optimal conditions, erythrosine had good linearity, with a correlation coefficients of 0.9996, linear range from 0.2 to 80 ng mL-1, and detection limits of 0.055 ng mL-1. The spiked recovery of samples was from 91.2 to 102.3%. The results indicate that the developed method was successfully applied to analytical erythrosine in candy and tomato sauce.3. A new method was developed fo r the sensitivity and selectivity determination of bright blue FCF and amaranth in soft drinks, wine, sweets and jelly by UV–Visible spectroscopy. Reduced graphene oxide/magnetite composites which were synthesis by a facile one–step solvothermal were used as an adsorbent for the magnetic solid phase extraction of synthetic colorants in food samples. Under optimal conditions, synthetic colorants exhibited good linearity, with correlation coefficients of 0.9994 and 0.9998, linear range of 0.6–60 ng mL–1 and 3–250 ng mL–1, and limit of detection of 0.012 and 0.05 ng mL– 1, respectively. The spiked recovery for samples was in the range of 92.19%–98.30%. The experimental results indicate that the proposed method was successfully applied to the analysis of bright blue FCF and amaranth in food samples.4. A new method was developed for the sensitivity and selectivity determination of atrazine and prometryn in environmental water sample by high-performance liquid chromatography–UV. Diatomite/Reduced graphene oxide/magnetite composites which is synthesis by a facile one-step solvothermal were used as an adsorbent for the magnetic solid phase extraction of triazine herbicides in environmental water. The effects of various experimental parameters, such as the kinds and amount of magnetic materials, sample pH, extraction time, selection of desorption solvent and etc, were optimized. Under optimal conditions, Atrazine and Prometryn exhibited good linearity, with correlation coefficients of 0.9995 and 0.9996, linear range of 0.5–120 ng mL-1and 1–120 ng mL-1, and limit of detection of 0.055 and 0.04 ng mL-1, respectively. The spiked recovery for samples was in the range of 95.23%–102.56%. The experimental results indicate that the proposed method was successfully applied to the analysis of triazine herbicides in environmental water. |
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