Method for rapidly determining lead and chromium in dairy products

Abstract

The invention belongs to the chemical detection analysis field and in particular relates to a technology for rapidly determining lead and chromium in dairy products by use of a microwave digestion-graphite furnace atomic absorption spectrometry. The method comprises the following steps: (1) preprocessing a sample; (2) preparing lead and chromium standard curve series solutions; (3) drawing lead and chromium standard curves; and (4) measuring the sample. Compared with the prior art, the method has the beneficial effects that the sample preprocessing time is short and is only 2.4h, the operation is simple, the harm to laboratory technicians can be reduced to the maximum extent due to use of microwave digestion, the environment is friendly, the whole microwave digestion process of the sample is performed in a closed environment, a small amount of target detection substances are volatized, the contamination of external substances is avoided, the detection result has high accuracy and good repeatability, lead and chromium in the dairy product can be measured simultaneously, and the method is suitable for the batch processing and measurement of samples, is suitable for determining the contents of lead and chromium in various samples such as raw milk, sterilized milk, modified milk, milk powder, fermented milk and the like, and has wide application range.

Description

technical field [0001] The invention belongs to the field of chemical detection and analysis, and in particular relates to a technique for quickly measuring lead and chromium in dairy products by microwave digestion-graphite furnace atomic absorption spectrometry. Background technique [0002] Lead is a multi-affinity poison that can damage the digestive system, reproductive system and nervous system of the human body to varying degrees, and is a potential carcinogen; chromium is an essential trace element for the human body and has certain effects on the human body. Physiological functions, but hexavalent chromium has a stimulating effect on the human respiratory tract and digestive tract, long-term intake can cause cell mutation and cancer, and excessive intake can even lead to death; in recent years, with people's increasing attention to food safety, food The pollution of medium and trace elements has been widely paid attention to by all walks of life in the society. Lead...

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Problems solved by technology

[0002] Lead is a multi-affinity poison that can damage the digestive system, reproductive system and nervous system of the human body to varying degrees, and is a potential carcinogen; chromium is an essential trace element for the human body and has certain effects on the human body. Physiological functions, but hexavalent chromium has a stimulating effect on the human respiratory tract and digestive tract, long-term intake can cause cell mutation and cancer, and excessive intake can even lead to death; in recent years, with people's increasing attention to food safety, food The pollution of medium and trace elements has received extensive attention from all walks of life. Lead and chromium are safety indicators that must be checked in dairy product quality testing, and their content is directly related to product safety.

[0003] The determination of lead and chromium in dairy products in my country generally adopts the national standard GB5009.12-2010 Determination of lead in food and GB5009.123-2014 Determination of chromium in food, the dry ashing sample pretreatment method commonly used in the standard, It is usually carried out in a high temperature and open experimental environment. At high temperature, some target detection substances are volatile, and the open experimental environment also increases the probability of contamination of the test samples. The dry ashing treatment sample has a long detection cycle, which is not conducive to the improvement of work efficiency. Improvement; in GB5009.123-2014, there is an expression of microwave digestion processing samples to determine chromium in food, but the experimental conditions in the standard cannot be used to completely digest some refractory dairy samples. In the method, there is no microwave digestion - rapid determination of lead and chromium in dairy products by graphite furnace atomic absorption spectrometry.

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