Methods for detecting the content of chromium ion in soil

Abstract

The invention relates to a method for using an atomic absorption spectrometry to detect the chromium ion content in the soil. The method has the specific steps that: firstly, the invention establishes a chromium standard concentration-absorbance curve, then, the soil sample is added with the distilled water for moisturization, after that, the concentrated sulfuric acid and the concentrated phosphoric acid are used for digestion, the heating is carried out till the soil sample emits the white smoke, then the concentrated nitric acid is added till a large amount of white smoke comes out and the soil sample turns white, and the digestion liquid turns yellow green; the digestion liquid is transferred to a standard volumetric flask, the pH value is regulated to 7, 1 percent of H2SO4 - 1 percent of Na2SO4 solution is added for dilution to a standard scale, the mixture is shaken evenly and placed still till the solution is clarified, the upper layer of clear solution is taken for the measurement of the absorbance under a wavelength of 213.9nm, and the chromium ion content in the soil sample can be obtained by comparison with the established standard curve in the step a. The measurement error of the chromium ion content in the soil sample which is measured by the method of the invention is within 3 percent.

Description

Technical field: [0001] The invention relates to a method for detecting chromium ion content in soil. In particular, a method for detecting chromium ion content in soil by atomic absorption method. Background technique: [0002] It is known that at least 20 kinds of heavy metals are highly toxic, and more than half of them are released into the environment in large quantities. Heavy metals are permanent pollutants that cannot be effectively degraded by physical, chemical, and biological methods. It is transferred from one form to another, and in a suitable environment, it can transform into a more toxic form, which poses a serious threat to human health through the transmission of food chains. Because heavy metal pollutants are difficult to control, And it is very toxic, so it is particularly important to monitor the migration and transformation of heavy metals. [0003] At present, the determination of chromium content in soil mainly adopts the diphenylcarbazide colorimet...

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Problems solved by technology

The disadvantage of this method is that the property of the measuring solution is very unstable, and it is easily oxidized by air to make the color darker; the potassium permanganate used for chromium oxide must be excessive, and the excess part is reduced with sodium nitrite, but the amount of sodium nitrite It is difficult to control the appropriate amount, the presence of potassium permanganate and sodium nitrite will affect the final determination of chromium content

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