Separation and enrichment of silica gel modified with thiomalic acid - flame atomic absorption spectrometry for the determination of trace lead and cadmium in water samples

Abstract

The invention discloses a flame atomic absorption spectrum method for separating, enriching and determining trace lead and cadmium in a water sample by using thiomalamic acid modified silica gel. The flame atomic absorption spectrum method comprises the following steps: taking macro-porous silica gel as a carrier and taking thiomalamic acid as a functional molecule to prepare the thiomalamic acid modified silica gel; taking the thiomalamic acid modified silica gel as an adsorbent to dynamically separate and enrich the lead and the cadmium, and establishing the flame atomic absorption spectrum method. In a concentration range of 0.5-10.0 micrograms / milliliter, a Pb (II) absorbance in an eluting solution and the concentration form a good linear relation: A=0.0122*C-0.0011 (C: micrograms / milliliter); in a concentration range of 0.1-5.0 micrograms / milliliter, a Cb (II) absorbance in the eluting solution and the concentration form a good linear relation: A=0.1898*C+0.001 (C: micrograms / milliliter); the detection limits of the Pb (II) and the Cd(II) are 12.41ng / mL and 0.79ng / mL. According to the flame atomic absorption spectrum method, the sensitivity and the selectivity of the detection are improved and the detection of low-concentration Pb (II) and Cd(II) is easy to be automatic.

Description

technical field [0001] The invention relates to a method for rapidly determining trace amounts of lead and cadmium by using chemical modification to prepare an adsorbent, enrichment and separation, and atomic absorption spectroscopy. Background technique [0002] With the advancement of global industrialization, heavy metal lead and cadmium pollution has posed a great threat to human beings. Therefore, it is urgent to develop sensitive, fast and convenient separation and enrichment technology of lead and cadmium to meet the needs of environmental testing and other aspects. . [0003] At present, the methods for separating and enriching lead and cadmium in water include chemical precipitation, chemical reduction, ion exchange, biological treatment and adsorption. Among them, the adsorption method is widely used because of its simplicity, high efficiency, and the regenerable and recyclable adsorbent. Among various solid adsorption materials, silica gel has good adsorption pe...

AI Technical Summary

Problems solved by technology

Directly using silica gel as an adsorbent for separation and enrichment has low selectivity. Therefore, it is necessary to chemically modify the surface of silica gel to prepare a selective adsorbent, and then separate and enrich lead and cadmium in the sample solution. to test

[0004] At present, there is no relevant research on the separation and enrichment of silica gel modified with thiomalic acid-determination of trace amounts of lead and cadmium in water samples by flame atomic absorption spectrometry

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