Method for determining 12 metal elements in soil and sediment

Abstract

The invention discloses a method for determining 12 metal elements in soil and sediment. The method comprises the following steps: S1, collecting the soil to be tested; S2, smashing the soil to be tested to a size capable of passing through a 180-mesh sieve; S3, taking a soil sample from a sample bottle to pace in a digestion device for digestion; S4, driving acid until 8ml-10ml of the digestion solution is remained; S5, statically cooling to room temperature, pouring into a 50ml volumetric flask, and using an automatic constant volume device to diluting the solution to the full scale; S6, standing for precipitation, and taking supernatant for centrifuging; S7, putting a sample liquid in an inductively coupled plasma mass spectrometer; and S8, calculating the content of the 12 metal elements in the soil sample according to the weight of the soil sample and the concentration of the digested solution. In summary, the method is reasonable, largely avoids the problem of blockage of a pipeline and an atomizer during instrument detection, improves the digestion efficiency, reduces the error of manual operation, and improves the determination accuracy of the metal elements in the soil andthe sediment.

Description

technical field [0001] The invention relates to the technical field of soil environmental protection detection, in particular to a method for measuring 12 kinds of metal elements in soil and sediment. Background technique [0002] Heavy metal pollution of the soil refers to human activities, the content of trace metal elements in the soil exceeds the background value, and the excessive content caused by excessive deposition is collectively referred to as soil heavy metal pollution. [0003] Heavy metals refer to metals with a specific gravity equal to or greater than 5.0, such as Fe, Mn, Zn, Cd, Hg, Ni, Co, etc.; As is a metalloid, but due to its chemical properties and environmental behavior are similar to heavy metals, Therefore, when discussing heavy metals, arsenic is often included, and some directly include it in the scope of heavy metals. Due to the high content of iron and manganese in soil, it is generally considered that they are not soil pollution elements, but u...

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Problems solved by technology

[0004] The standard HJ803-2016 stipulates the determination of 12 kinds of metal elements in soil and sediment--aqua regia extraction-inductively coupled plasma mass spectrometry. This method is accurate and convenient. The only disadvantage is that the digestion solution needs to be filtered through filter paper and then constant volume. This method takes a long time to filter. If the filter paper is damaged or improperly operated, it is easy to cause particles to enter the filtrate, thereby blocking the sample tube or nebulizer during instrument measurement. In actual experiments, we found that the filtrate was first made to volume after digestion The method of taking the supernatant and centrifuging not only saves time and reduces the use of consumables, but also largely avoids the clogging problem of subsequent instrument detection

[0005] In the actual soil testing operation, we found that the traditional air-drying process was slow, wasting time, and then slowed down the testing time. At the same time, we also found that the digestion process was often incomplete due to the uneven mixing problem, which had a negative impact on the testing results. In addition, the digestion time is generally long and the efficiency is low. In the process of constant volume, the test personnel may have the problem of wrong drops or less drops. The deviation of constant volume also has a certain impact on the test results.

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