| High performance liquid chromatography (HPLC) and Ion chromatography (IC) as two important analytical measurements have some advantages, such as high-speed analysis. high sensitivity, convenience, simultanence analysis of multiple components and so on. Now, they have been used in many areas of food, environment, medicine, agriculture, industry, since they were developed1970’s.The thesis includes two sections:review and research report. In the review section, the development and advantages of HPLC and IC were simply summarized. The application of HPLC in environmental analysis, sample preparation and the application of IC in food analysis were detailedly remarked. The object and significance of this study were simply summarized. In the research report section, it main includes the extraction and clean-up of chlorpyrifos and TCP in water and soil samples, with HPLC for the determination. Carbohydrate in milk powder, organic acids in hawthorn fruit and ebony were determined by ion chromatographyThe research report section includes four parts:1. Determination of Chlorpyrifos and its Main Degradation Product TCP in Water Samples by Dispersive Liquid-liquid Microextraction Based on Solidification of Floating Organic Droplet Combined with High Performance Liquid ChromatographyThis article reports an alternative method for simultaneous extraction and determination of chlorpyrifos and its main degradation product3,5.6-trichloro-2-pyridinol (TCP) in water samples which involves dispersive liquid-liquid microextraction based on solidification of floating organic droplet followed by high performance liquid chromatography with ultraviolet detection.1.0mL of methanol and70μL of1-dodecanol were used as the disperser solvent and extraction solvent. respectively. After the floated extraction solvent had solidified in an ice bath. it was dissolved with methanol. Under the optimized conditions, enrichment factors for chlorpyrifos and TCP were96and114, respectively. Linear calibration curves were obtained in the range of1-50μg/L, with correlation coefficients (R2)>0.9955. The limits of detection were0.12μg/Lfor chlorpyrifos and0.10μg/L for TCP. The recoveries of spiked real water samples ranged between84.54%and102.29%, with the relative standard deviation being0.80%-14.03%.2. Dispersive solid phase extraction coupled with HPLC-UV for simultaneous determination of chlopyrifos and3,5,6-trichloro-2-pyridinol in soil samplesA simple method was proposed for simultaneous determination of chlorpyrifos and its hydrolysis and biodegradation product3.5,6-trichloro-2-pyridinol (TCP) in soil samples. The analytes were extracted with ethyl acetate (EtOAc) under optimized pretreatment conditions such as the type, volume and pH of extraction solvent. Clean-up of the extract from soil was conducted by dispersive solid phase extraction (DSPE) using activated carbon as the adsorbent. High performance liquid chromatography with ultraviolet detection (HPLC-UV) was used for simultaneous determination of the two analytes. Under the optimized HPLC conditions, the limits of detection (LOD), obtained on signal-to-noise ratio (S/N) of3, for chlorpyrifos and TCP were0.0080mg/kg and0.0120mg/kg, respectively. Linear calibration curves were obtained in the range of0.05-2.00mg/kg and0.03-2.00mg/kg for chlorpyrifos and TCP, respectively. The spike recoveries from soil ranged from89.38%to113.53%, and the relative standard deviation (RSD) was in the range of0.80%-13.98%.3. Determination of Glucose, Sucrose and Lactose in Milk powder by Ion ChromatographyA high performance anion exchange chromatographic-pulse amperometric detection method was applied to determine glucose, sucrose and lactose in milk powder. With37mmol/L NaOH as elution and citric acid as precipitator, METROSEP CARB1(150mm×4.0mm) anion exchange column and pulsed amperometric detector were used for separator column and detection, respectively. The linearity range of glucose, sucrose and lactose were1-40mg/L,1-50mg/L.1-50mg/L separately, and their correlation coefficients were0.99656,0.99679,0.99846, correspondingly. Detection limits were0.014mg/L,0.091mg/L,0.083mg/L.The relative standard deviation was between1.14%and4.96%. The recoveries were between90.13%and104.83%. This method was suitable for rapid determination of glucose, sucrose and lactose in milk powder, owing to a short analysis time and simple pretreatment.4. Determination of Organic Acids in Hawthorn fruit and Ebony by Ion ChromatographyA method was developed for determination of six organic acids (oxalic acid, citric acid, DL-malic acid, succinic acid, acetic acid, and propionic acid), simultaneity, and it was applied to determine organic acids in Hawthorn fruit and Ebony. Chromatographic separation was performed on a METROSEP Organic Acids (250x7.8mm) with Suppressed Conductivity Detection.10mmol/L LiCl and the highest pure water were used as the regenerative solution.0.5mmol/L sulfuric acid and10%acetone was used for the eluent, the flow rate of which was0.6ml/min. Six organic acids could be separated absolutely in17minutes, the related coefficient(R) were between0.9988and0.9996, the detection limits were between0.05mg/L and1.20mg/L, and the spike recoveries ranged from90.54%to112.86%. The citric acid and DL-malic acid were determined in Hawthorn fruit and Ebony, and the quantity of citric acid was the most. This method could be used to determine the quantity of organic acids in Hawthorn fruit and Ebony. |
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