Study On The Detection Methods Of Four Food Antiseptics

As we approach the 21st century,people require food convenient,nutrition and safety.Among the three factors,safety factor is taken as given,so we can say safety factor is the base line,nutrition factor is the basis,convenient factor is the requirement.So food safety question has been put on the agenda in our country.The problem of food preservative is one of most important factors of food safety,it is very necessary to establish a convenient speediness and exact method.The article contains the follow aspects:1.To establish the method of detecting hydrogen peroxide in fresh milk based on using spectrophotometry.The method is researched on the maximum absorbed wavelength,linear range, color development reagent and colorimetry time,deposition time.The method is also researched on the interference of peroxides.Establish the optimization experimental term of the method of detection of hydrogen peroxide in fresh milk.And then detect fresh milk sample in Chongqing market using this method.2.To establish the method of detecting benzoic acid,sorbic acid,dehydroacetic acid in foods based on the use of GC and Re-HPLC at the same time and search for the optimization experimental term of each other methods.Adopt the two methods to detect random sample of three food samples -sauce, syrup,preserved bean curd in Chongqing market.We get these conclusions by Experiment research:1.The optimization experimental term of detecting hydrogen peroxide in fresh milk by spectrophotometry is:The content of hydrogen peroxide being 0-200ug,the wavelength being 406nm,titanium reagent being 5.0ml,within 30 min of deposition,the correlation coefficient of the method was found to be over 0.9997,with an average recovery of 91%-104%.The detection limit of H₂O₂ is 0.29 mg/l.2.Research of interferential experiments finds:Peracetic acid can interfere experimential results which use spectrophotometry to detect hydrogen peroxide in fresh milk,the interferential content range is the same as content of hydrogen peroxide.Benzoperoxide can't interfere experimential results.So the method can't applicable to detect hydrogen peroxide in fresh milk which sterilized by Peracetic acid.And then experimential data shows the content of hydrogen peroxide don't change within milk's shelf life.3.The optimization experimental term of detecting benzoic acid,sorbic acid,dehydroacetic acid in foods based on the use of GC at the same time is:the temperature of pillar(adopt Rtx-5) is:90℃keep 2 min,and then keep 50℃/min rate going up to 150℃;the temperature of going in stomata is 230℃;he temperature of detector is 230℃;the flow of Hydrogen 30ml/min;the flow of air is 300ml/min;the makeup flow is 30ml/min;split ratio is 1:1.This method which is simpleness and speediness can take the three antiseptics apart within 9 minutes.This method can detect benzoic acid, sorbic acid,dehydroacetic acid with fine resolution,The relative standard deviations respectively are 2.37%,2.72%,2.03%,The average recovery respectively are 99.80%,98.77%,100.14%.The detection limits respectively are 1.2μg,1.1μg,1.0μg.and there is no disturbance by saccharin sodium was found in the process.This method is validated in terms of simpleness,sensitivity, selectivity and accuracy in detecting benzoic acid,sorbic acid,dehydroacetic acid in foods,it can be used to detect three antiseptics - benzoic acid,sorbic acid,dehydroacetic acid in syrup,beverage, sauce,preserved bean curd and so on at the same time,so it can improve efficiency greatly.4.The optimization experimental term of detecting benzoic acid,sorbic acid,dehydroacetic acid in foods based on using RE-HPLC at the same time is:mobile phase is methanol+0.02mol/L ammonium acetate(5:95 V/V);and elution flow rate is 1mL/min;chromatogram pillar is Agilent ZORBAX Eclipse C 18柱(150mm 4.6mm,3μm ),normal temperature;the detection wavelength is 230nm,the width of apex is 16nm;the wavelength of consulting is 360nm,the width of apex is 16nm.Automatic,the injection volume is 30μL.This method can detect benzoic acid,sorbic acid,dehydro acetic acid with fine resolution.The relative standard deviations are 0.50%,0.46%,0.66%,the average recovery are 104.8%,107.2%,96.9%.The detection limits are 12ng,8ng,10ng.the concentration limits are 0.004g/kg,0.003g/kg,0.003g/kg. Pigments,acetosulfamine kalium,and saccharin sadium have no disturbance in the process.This method is validated in terms of sensitivity,accuracy,and selectivity in detection of benzoic acid, sorbic acid,dehydro acetic acid in foods.