Study On The Simultaneous Detection Technique Of Five Preservatives In Foods

To establish the method of detecting benzoic acid, sorbic acid, dehydroacetic acid,methyl4-hydroxybenzoate, ethyl hydroxybenzoate in foods based on the use of GC andHPLC at the same time and search for the optimization experimental term of each othermethods. Adopt the two methods to detect random1e of five food samples-sauce syrup,preserved bean curd in xi’an market.We get these conclusions by Experiment research:（1）The optimization experimental term of detecting benzoic acid, sorbic acid,dehydroacetic acid, methyl4-hydroxybenzoate, ethyl hydroxybenzoate in foods based on theuse of GC at the same time is: he temperature of detector is300℃;the temperature of going instomata is200℃; the temperature of pillar is:65℃，keep1min, and then keep30℃/min rategoing up to190℃，keep2min，and then keep30℃/min rate going up to280℃；the flow ofHydrogen45mL/min; the flow of air is450mL/min;.This method which is simpleness andspeediness can take the three antiseptics apart within9minutes. This method can detectbenzoic acid, sorbic acid, dehydroacetic acid, methyl4-hydroxybenzoate, ethylhydroxybenzoate with fine resolution, The relative standard deviations respectively blow5%,The average recovery respectively up90%.The detection limits respectively between0.196mg/kg~1.452mg/kg.This method is validated in terms of simpleness,sensitivity,selectivity and accuracy in detecting benzoic acid, sorbic acid, dehydroacetic acid,methyl4-hydroxybenzoate, ethyl hydroxybenzoate in foods.（2）The optimization experimental term of detecting benzoic acid, sorbic acid,dehydroacetic acid, methyl4-hydroxybenzoate, ethyl hydroxybenzoate in foods based onusing HPLC at the same time is: chromatogram pillar is Agilent C18(250mmx4.6mm，5μm)，temperature is35℃;the detection wavelength is254nm; Automatic，the injection volume is10μL. This method can detect benzoic acid, sorbic acid, dehydroacetic acid, methyl4-hydroxybenzoate, ethyl hydroxybenzoate with fine resolution. The relative standarddeviations below5%,the average recovery up90%.the concentration limits between0.065~0.601㎎/kg. This method is validated in terms of sensitivity, accuracy, and selectivityin detection of benzoic acid, sorbic acid, dehydroacetic acid, methyl4-hydroxybenzoate, ethylhydroxybenzoate in foods.（3）With the gas chromatography method for benzoic acid and sorbic acid detection in food of GB/T5009.29-2003, parabens detection in food of GB/T5009.31-2003,and fdehydroacetic acid detection in food of GB/T5009.121.2003,food of different kinds sold inXi’an were tested.Furthermore,the gas chromatography simultaneous method and highperformance liquid chromatography simultaneous method were also introduced to thesefood,which were more faster and efficient for judgements on the five presevatives in food.