Analysis Method Research And Application Of Synthetic Pigment And Industrial Dye In Food

ObjectiveFood safety has become the focus problems of the people concerned about. Synthetic pigment overspray and excessive use and illegal adding of industrial dye are seriously affect the food safety and physical health of consumers. So it is particularly important to detect the synthetic pigment and industrial dye in food. First of all, the complexity of a test method,in a certain extent, directly affects the accuracy of the test results, especially for grass-roots inspection agencies, a kind of simple and feasible method is the key to ensure the accuracy of the test results. Secondly, it should be even more to improve the accuracy of detection for illegally added in food. This study aims to establish two kinds of simple, sensitive and accurate methods, Flour without pigment precipitation-HPLC and ultra high performance liquid chromatography-tandem mass spectrometry, to determinate the synthetic pigment and industrial dye in meat products, the experiment will optimize for sample pretreatment, chromatographic and mass spectrometry conditions, respectively; And then sampling analysis of pastries, cooked meat products in Dezhou city and counties will be carried out by the established methods, in order to get across the situation of the synthesis pigment and industrial dye in food.MethodsThe first method, high performance liquid chromatography with diode array detector (HPLC-D AD) determination six kinds of synthetic pigment in pastry, operate as followed:after sample adsorpted by powder polyamide, starched without pigment precipitate and then centrifuge to make solid phase and water phase clear stratification, thereby removing natural pigment, collect and enrich the synthetic pigment, samples gradient eluted by mobile phase of 0.02 mmol/L aqueous ammonium acetate and methanol and separated with C-18 chromatographic column. The synthetic pigment concentrations in the sample extract were judged and quantified by the retention time and peak areas, respectively. The second method, triple quadurupole liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination of seven kinds of synthetic pigment and ten kinds of industrial dye, using acetone aqueous solution to extract samples, employing frozen centrifugation technology to remove fat, employing ultra high performance liquid chromatography combined with triple quadurupole tandem mass spectrometry to simultaneously analysis seven kinds of synthetic pigment and ten kinds of industrial dye. Samples gradient eluted by mobile phase of 0.02 mmol/L aqueous ammonium acetate and methanol to separate seventeen pigment absolutely.ResultsThe first method, The six synthetic pigment had good linear relations with the range of 0.500～50.0 μg/ml and all correlation coefficient (r) more than 0.9998, detection limit of the six synthetic pigment were 0.035-0.060 mg/kg, the mean recoveries were in the range of 81.0%～97.9%.the intra-day and the inter-day coefficient of variation 1.9%～8.4%,2.8%-8.3%. The proposed method was demonstrated to be low detection limit, good repeatability, high precision, saving time and reagent, and was successfully applied to analyze of many synthetic pigment in pastry from primary. The second method, Each pigment determined one quantitative ion and two qualitative ion, qualitative accurate and reliable. The pigments had good linear relations with the range of 1.00-200μg/L (except Sunset Yellow 10.0-200μg/L)and all correlation coefficient (r) more than>0.99. This method’s limit detection was 0.003mg/kg (except Sunset Yellow is 0.03mg/kg, Astranzon orange G、Astranzon orange、Rhodamine B are 0.0003mg/kg), the mean recoveries played with standard concentrations at 0.05mg/kg(except sunset yellow), 0.50mg/kg and 2.0mg/kg levels, and the range were 83.6-99.3%. the intra-day and the inter-day coefficient of variation 2.6%-6.5%,2.6%～7.2%. The proposed method was demonstrated to be accurate and reliable, operation fast and easy, saving commodities and reagent, and was successfully applied to analyze of synthetic pigment and industrial dye in meat products.ConclutionThis paper studies after centrifugal extraction of the samples, using HPLC-DAD to determinate of synthetic pigment in pastry, verify the feasibility of the pretreatment method, optimized the conditions of the performance liquid chromatography (HPLC) and detector. At the same time, determinate seven kinds of synthetic pigment and ten kinds of industrial dye by triple quadurupole liquid chromatography-tandem mass spectrometry (LC-MS/MS), test the reliability of the pretreatment method which using acetone aqueous solution to extract samples, employing frozen centrifugation technology to purify, discuss the effect of the relative position of the mass spectrometry injection needle and the cone hole. The two methods were proved to be operation fast, accurate and reliable, saving reagent, by determination of actual samples, and satisfied to analyze of synthetic pigment in pastry and synthetic pigment and industrial dye in meat products.