Method for determining content of cadmium in soil by ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry)

Abstract

The invention discloses a method for determining the content of cadmium in soil by ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry). The method adopts an extraction-reextraction system to deal with a soil sample digested by mixed acid and solves the problem of shifting of the cadmium spectral absorption peak, caused by concentration of cadmium in low-cadmium soil digestion solution and soil matrix. The method comprises the steps of enabling cadmium ions in the digestion solution and sodium diethyldithiocarbamatre to form a chelate in mediums with certain pH value, then performing extraction separation by CCl4 organic phase, adding with nitric acid-hydrogen peroxide mixed solution to oxidize and destroy the chelate, performing reextraction to cadmium in water phase and determining the content of cadmium; experimental results show that the method is simple and feasible, has high precision and good accuracy, can determine low cadmium content of the soil, can make up the blank that the ICP-AES cannot accurately determine the cadmium content in the soil and provides new reference for detection analysis of the cadmium content of the soil.

Description

technical field [0001] The invention relates to a method for measuring cadmium content, in particular to an ICP-AES method for measuring cadmium content in soil. Background technique [0002] Inductively coupled plasma emission spectrometer (ICP-AES) is a spectral analysis instrument using inductively coupled plasma moment as the excitation light source. It has the advantages of safety, simplicity and the ability to simultaneously determine the content of multiple elements. The detection limit of the element is 0.001 mg / L. ICP-AES has been applied in the determination of heavy metals in soil. However, ICP-AES cannot be directly applied to the determination of cadmium in soil at present: on the one hand, in the natural environment, especially in farmland soil, the content of cadmium, an important heavy metal element, in soil is low, and is affected by ICP-AES. Due to the restriction of the detection limit of AES, it is difficult to detect the cadmium content in the soil; on...

AI Technical Summary

Problems solved by technology

However, ICP-AES cannot be directly applied to the determination of cadmium in soil at present: on the one hand, in the natural environment, especially in farmland soil, the content of cadmium, an important heavy metal element, in soil is low, and is affected by ICP-AES. Due to the restriction of the detection limit of AES, it is difficult to detect the cadmium content in the soil; on the other hand, the soil composition is complex. If the cadmium content is directly measured by ICP-AES, the soil matrix contained in the test solution after digestion will seriously interfere with the determination of ICP-AES. The spectral absorption peak of cadmium element is shifted, so it is impossible to obtain accurate measurement results of cadmium content

Images