Pre-treatment and quantitative analysis method for rapid determination of content of cadmium element in rice

Abstract

The invention relates to a pre-treatment and quantitative analysis method for rapid determination of the content of the cadmium element in rice. The method comprises the following steps (1) crushing rice into powder; (2) preparing an agar solution with a concentration of 0.8 to 1.5 gL; (3) weighing a plurality of parts of rice powder as parallel samples, respectively subjecting the parallel samples to suspension and volume fixation with the agar solution prepared in the step (2), carrying out dilution with dilute nitric acid so as to obtain to-be-measured sample liquids with rice concentration of 4 to 16 gL and directly diluting the agar solution obtained in the step (2) with dilute nitric acid so as to obtain a blank sample; (4) preparing cadmium standard solutions, determining the absorbance value of each cadmium standard solution by using graphite furnace atomic absorption spectrometry and drafting a cadmium element standard curve; and (5) determining the absorbance values of the to-be-measured sample liquids and the blank sample and calculating cadmium content of the to-be-measured sample liquids. The method provided by the invention is simple and fast, can rapidly detect the content of the cadmium element in rice and has good accuracy and repeatability.

Description

technical field [0001] The invention belongs to the technical field of rapid analysis and detection, in particular to a pretreatment and quantitative analysis method for rapidly determining the content of cadmium in rice. Background technique [0002] In the quantitative analysis method for detecting the content of cadmium in rice, it is usually necessary to digest the pulverized sample with acid with the help of pre-treatment equipment before detection. Commonly used sample pretreatment methods include: wet digestion, dry ashing, microwave digestion and high-pressure digestion tank digestion, etc. Among these methods, the wet method consumes a large amount of acid, takes a long time, and is difficult to operate; the dry ashing method needs to first heat the sample to carbonize, then transfer it to a muffle furnace for high-temperature ashing, and add acid after cooling. The process of dissolving to a constant volume is cumbersome and time-consuming; high-pressure digesti...

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Problems solved by technology

Among these methods, the wet method consumes a large amount of acid, takes a long time, and is difficult to operate; the dry ashing method needs to first heat the sample to carbonize, then transfer it to a muffle furnace for high-temperature ashing, and add acid after cooling. The process of dissolving to a constant volume is cumbersome and time-consuming; high-pressure digestion tank digestion requires the use of an oven to heat and digest the samples and digestion solution in the tank, which also has the problem of time-consuming; microwave digestion uses microwave heating to digest samples, although Compared with the previous digestion methods, the pretreatment speed has been greatly improved, but the time required for the digestion and acid removal process is still measured in hours

Therefore, the pretreatment process of traditional quantitative analysis of cadmium in rice is cumbersome, time-consuming and labor-intensive, and the cumbersome steps have relatively high requirements for testing personnel, which results in long time-consuming, difficult operation and inaccurate results for the entire quantitative analysis method. also difficult to guarantee

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