Pretreatment method for measuring heavy metal elements in grease food

Abstract

The invention discloses a pretreatment method for determining heavy metal elements in grease food. The method comprises the following steps: sampling, preparing a mixed emulsion of an initial lauryl sodium sulfate solution and a sample as a control group 1, performing a stability experiment on the control group 1, and testing the control group 1; recording stability experiment data 1, reducing the concentration of the initial lauryl sodium sulfate solution, preparing a mixed emulsion with a sample as a control group 2, testing the control group 2, recording stability experiment data 2, repeating N times to obtain N groups of stability experiment data, and screening and comparing the N groups of stability experiment data to obtainan optimal lauryl sodium sulfate solution concentration; and according to the optimal lauryl sodium sulfate solution concentration, adding nitric acid and hydrogen peroxide to carry out emulsification digestion pretreatment on the sample. The method has the beneficial effects that the digestion effect is good, a sample to be detected can be completely digested, and filtering or degreasing is not needed; and the target element can be completely fused out so that the subsequent measurement result is relatively high in precision and is close to a true value.

Description

technical field [0001] The invention relates to the field of food testing, in particular to a pretreatment method for measuring heavy metal elements in oily food. Background technique [0002] In the detection of heavy metal elements in food, according to GB5009.268-2016 "National Food Safety Standard for the Determination of Multi-Elements in Food", GB5009.11-2014 "National Food Safety Standard for the Determination of Total Arsenic and Inorganic Arsenic in Food" , GB5009.12-2017 "National Food Safety Standard for the Determination of Lead in Food", the pretreatment method of microwave digestion stipulated in the pretreatment method is: "weigh the sample and add nitric acid, and digest it in a microwave digestion apparatus. After cooling, take it out and remove the acid , make up to volume with water." [0003] The composition of oil is a compound formed by the combination of fatty acid and glycerol. For oil samples, the traditional nitric acid digestion pretreatment metho...

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Problems solved by technology

[0003] The composition of oil is a compound formed by the combination of fatty acid and glycerol. For oil samples, the traditional nitric acid digestion pretreatment method is prone to incomplete digestion and oil suspension.

It is also necessary to degrease or filter the sample, which will cause the liquid to be turbid and cannot completely dissolve the target element, which will not only increase the workload, affect the work efficiency, but also affect the accuracy of the determination of metal elements

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