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CN-120908167-B - Method for detecting heavy metal content of food additive

CN120908167BCN 120908167 BCN120908167 BCN 120908167BCN-120908167-B

Abstract

The invention belongs to the technical field of detection, and particularly relates to a method for detecting heavy metal content of a food additive. The detection method comprises the steps of (1) sample pretreatment, (2) preparation of heavy metal standard solution with serial concentration, testing of net strength by an ICP-MS instrument to obtain a standard working curve, and (3) testing of net strength of sample solution and blank solution by the ICP-MS instrument, and obtaining of concentration of heavy metal in the food additive by combining of the standard working curve to further obtain content of heavy metal in the food additive. The detection method can be used for detecting heavy metal arsenic in the compound meat product thickener, the sample structure is further destroyed by ultrasonic collaborative extraction of enzymolysis-auxiliary extracts and temperature control by using gradient ultrasonic combination, the arsenic dissolution efficiency is improved, EDTA and citric acid are adopted to complex metal ions, and the fixation effect of other ions on arsenic is reduced by the cooperation of a plurality of components, so that the accuracy of detection results is improved.

Inventors

  • YANG YUXIN
  • DU GUANGHUA

Assignees

  • 宝鸡市质量技术检验检测中心

Dates

Publication Date
20260505
Application Date
20250813

Claims (5)

  1. 1. The method for detecting the heavy metal arsenic content in the compound meat product thickener is characterized by comprising the following steps of: (1) Sample pretreatment: weighing a compound meat product thickener, adding water, adding papain and neutral protease, carrying out enzymolysis, continuing to add auxiliary extracting solution after enzyme deactivation, carrying out gradient ultrasonic treatment after uniform mixing, centrifuging, taking supernatant, filtering with a filter membrane, washing filtrate with water into a volumetric flask, adding rhodium solution as an internal standard element, carrying out constant volume with water to the scale of the volumetric flask, and shaking uniformly to obtain a sample solution; Adding papain and neutral protease into water, heating, inactivating enzyme, continuously adding auxiliary extracting solution, adding rhodium solution as internal standard element, adding water to volume to scale of volumetric flask, shaking uniformly to obtain blank solution; (2) Preparing heavy metal standard solutions with serial concentrations, and testing the net strength by adopting an ICP-MS instrument to obtain a standard working curve; (3) Testing the net strength of the sample solution and the blank solution by using an ICP-MS instrument, and combining the standard working curve to obtain the concentration of heavy metal in the food additive, thereby further obtaining the content of heavy metal arsenic in the compound meat product thickener; the auxiliary extracting solution in the step (1) comprises 0.05 to 0.1 weight percent of EDTA, 0.1 to 0.3 weight percent of citric acid, 0.03 to 0.05 weight percent of zinc sulfate and the balance of water; The gradient ultrasonic conditions in the step (1) are that the first stage is 100W ultrasonic for 5 minutes, the second stage is 120W ultrasonic for 5 minutes, the temperature of the water bath is controlled to be 25-30 ℃ in the ultrasonic process, and the ultrasonic treatment is finished and the ultrasonic treatment is kept stand for 10-20 minutes.
  2. 2. The method for detecting heavy metal content of food additives according to claim 1, wherein the amount of papain and neutral protease in the step (1) is 0.5-1wt% of the food additives.
  3. 3. The method for detecting heavy metal content of food additive according to claim 1, wherein the step (1) is performed by filtration using a 0.22 μm filter.
  4. 4. The method for detecting heavy metal content of food additives according to claim 1, wherein in the step (2), 0, 0.2, 1,2, 5, 10, 20 and 50 mug/L of metal standard solution is freshly prepared by using metal standard use solution, 10mL of rhodium solution with the concentration of 50 mug/L is added as an internal standard element before volume fixing, a standard working curve is drawn, the series of concentration of metal standard solution is injected into an ICP-MS instrument, and the content of metal is measured by using an on-line internal standard method, so that the standard working curve is obtained.
  5. 5. The method for detecting heavy metal content of food additives according to claim 1, wherein the ICP-MS instrument test conditions are: High frequency power 1.40kW; The plasma gas flow is 13.0L.min -1 ; Carrier gas flow rate 0.8l.min -1 ; he flow rate 4.0ml.min -1 ; sample lifting amount is 0.1mL.min -1 ; sampling depth 10.0mm; Sampling nickel cone, wherein the diameter of the pore plate is 1.0mm; Intercepting nickel cone, wherein the diameter of the pore plate is 0.4mm.

Description

Method for detecting heavy metal content of food additive Technical Field The invention belongs to the technical field of detection, and particularly relates to a method for detecting heavy metal content of a food additive. Background With the rapid development of the food industry, the compound food additive is widely applied to food processing due to the functional diversity and the process convenience. However, heavy metal arsenic (As) which may remain in the built additives is an important risk factor for food safety due to its high toxicity and cumulative hazard. At present, the detection of arsenic in the compound additive mainly depends on a wet digestion-atomic fluorescence spectrometry and a dry ashing method, but the method has the following problems that a large amount of strong acid (nitric acid, sulfuric acid and the like) is required for wet digestion, acid is required to be supplemented for many times in the digestion process, the temperature is strictly controlled to avoid carbonization, the operation is tedious and harmful gas is easy to generate, and the dry ashing method requires long-time high-temperature ashing, so that the volatilization loss of arsenic is possibly caused, and the fluctuation of recovery rate is large. Meanwhile, the complex components (such as phosphate, organic acid and the like) of the compound additive can inhibit the reduction of arsenic or complex with a detection reagent, so that false negative or signal inhibition is caused. The prior art is mostly solved by multiple dilution or separation and purification, but the detection period is prolonged. Chinese patent CN104198417B discloses a method for determining heavy metal arsenic in a compound food additive, and the compound food additive sample is digested by wet method to prepare a sample solution. Under the irradiation of light source, introducing sample into atomizer, drying, ashing and atomizing, and making it enter optical system, monochromator, detector and electronic circuit to detect its absorbance, whose intensity is proportional to absorbance, and adopting standard curve method to make quantitative measurement so as to calculate total arsenic content in the compound food. The compound meat product thickener is a food additive specially used for improving the texture, taste and stability of meat products. It is usually formulated from a variety of single thickeners, stabilizers and other functional ingredients, and is capable of enhancing the water retention, elasticity and shape retention of the meat product while preventing stratification or water separation. The compound meat product thickener (figure 1) of Qingdao Dehui ocean biotechnology Co., ltd is a product with a large market share, is well accepted by industry clients, and is especially used in the production of fish balls, crab sticks, shrimp slips, fish tofu, cuttlefish balls and other products such as frozen surimi (minced shrimp) with constant speed. However, because of the difference between the standards of the heavy metal content in the food additives required by different countries, in order to cope with the difference, the food manufacturers need to perform quality control according to the specific requirements of the target market. Because of the complexity of the matrix of the formulated meat product thickener, the morphology of the arsenic present, and potential interference during pretreatment, the prior art is not ideal in determining the arsenic content therein. The article "reversed phase HPLC-ICP-MS method for synchronously detecting common food additives and heavy metals in food" (Yan Tingzhao, etc.) discloses the use of zinc sulfate and potassium ferrohydride for pretreatment of food additives, but the method is not good in detection accuracy for arsenic in a compound meat product thickener. Therefore, a method for detecting heavy metal content of food additives specially aiming at a compound meat product thickener is needed. Disclosure of Invention The invention aims to provide a method for detecting heavy metal content of a food additive. In order to achieve the above object, the present invention provides the following technical solutions: A method for detecting heavy metal content of a food additive comprises the following steps: (1) Sample pretreatment: Weighing food additives, adding water, adding papain and neutral protease, carrying out enzymolysis, inactivating enzyme, continuing to add auxiliary extracting solution, uniformly mixing, carrying out gradient ultrasonic treatment, centrifuging after finishing, taking supernatant, filtering with a filter membrane, washing filtrate with water into a volumetric flask, adding rhodium solution as an internal standard element, and carrying out constant volume with water to the scale of the volumetric flask to be uniformly shaken to obtain a sample solution; Adding papain and neutral protease into water, heating, inactivating enzyme, continuously adding auxiliary extracting so