Method for determining arsenic content of plants

Abstract

The invention discloses a method for determining the arsenic content of plants. The detection process of the method comprises the following steps: weighing 0.5g of plant sample sieved by 100 meshes, putting into a 50mL glass colorimetric tube with scales and a stopper, adding 35mL of concentrated nitric acid HNO, capping and immersing for the night, and meanwhile doing a reagent blank without samples; the next day, heating and digestion for 2 hours with a water bath at 100 DGE C; after heating and digestion are finished, putting a Vapor Block, and evaporating nitric acid to be dry at 120-130 DEG C; after catching acid is finished, taking down the colorimetric tube, cooling, adding 5mL of hydrochloric acid and 5mL of mixed liquid of 50g / L thiourea and 50g / L ascorbic acid, and adding ultrapure water to cause the constant volume to be 25mL; and after filtering, using an atomic fluorescence analyzer to determine the arsenic content. Compared with the traditional method for determining the arsenic content, the method has the beneficial effects that the advantages are significant, and the detection speed is high; the plant samples can be processed in batches, the practicality of nitric acid is greatly reduced, less nitrogen oxide waste gas is generated, and the environmental pollution is greatly reduced; and the detection result of the method has high accuracy and good repeatability.

Description

Technical field [0001] The invention relates to the field of measuring content, more specifically, it relates to a method for measuring arsenic content in plants. Background technique [0002] Soil is the material basis for human survival and an important part of the human ecological environment. However, due to the massive discharge of industrial wastes and the massive application of pesticides and chemical fertilizers, soil arsenic pollution has become more and more serious, which directly leads to soil degradation, reduced productivity, and harm to human health. Arsenic is widely distributed in the natural air, water and soil. Excessive accumulation of arsenic in the soil will inhibit the growth of soil microorganisms and the activity of soil enzymes, thereby affecting the physiological metabolism of plants. Soil contaminated by arsenic can eventually endanger human health through water, plants and other media. There are many methods and technologies used to remove soil arse...

AI Technical Summary

Problems solved by technology

[0004] Hot plate digestion and microwave digestion are commonly used in the pretreatment of atomic fluorescence analysis. The operation of both is relatively simple, but the former takes a long time, has a high blank value, and produces a large amount of NO during the digestion process. 2 , pollute the environment; and the latter has two methods for catching acid from the sample after microwave digestion, using the Vapor Block acid catching device to catch the acid or transferring the sample from the digestion tube to the crucible to catch the acid on the electric heating plate, no matter which one is used method, several transfers are required in the middle process, which affects the recovery rate of the standard substance, and it needs to be equipped with a microwave digestion instrument, and the experimental conditions are relatively high

In addition, the two digestion processes are not suitable for the detection of large batches of samples (more than 40 samples / time)

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