Method for separating and enriching trace lead in substrate

Abstract

The invention discloses a method for separating and enriching trace lead in a substrate, which comprises the following steps: adding an alkaline precipitator into the substrate with shaking till the pH value of the solution is 7 to 9 and gelatinous precipitate appears in the solution; centrifuging the solution to obtain separated precipitate and supernate and removing the supernate; and accordingto test requirements, dissolving the precipitate in acid, fixing volume, and performing quantitative or fingerprint analysis on the lead in the solution. In the invention, a precipitation-centrifugation process is used to remove a large amount of Na, K and other ions which are not precipitated in the substrate from the supernate, the trace lead ions are separated and enriched at one step, the operation is simple and convenient, the repeatability is high, the recovery rate is high, fewer pollutants are introduced, and the method can be used for samples in which the substrate has high concentration and complex components.

Description

technical field [0001] The invention relates to a method for separating trace lead, in particular to a method for separating and enriching trace lead in a sample with high matrix concentration and complex composition. Background technique [0002] In the detection of lead and lead fingerprints, the traditional detection method is to directly detect the samples after digestion. For biological, food, environmental and other samples, the lead content is low, the relative matrix concentration is high, and the elements are complex. In the determination, the matrix effect will seriously interfere with the sensitivity, precision and accuracy of the instrument test, and will also cause baseline drift. , injection port contamination or even blockage. [0003] In order to overcome the various problems brought by the traditional detection methods and further improve the sensitivity, precision and accuracy of the detection methods, the technology of pre-separating and enriching the lea...

AI Technical Summary

Problems solved by technology

[0005] The disadvantages of the above separation and enrichment techniques are: the steps are relatively cumbersome, and the enrichment and separation are affected by many conditions; different samples, enrichment and elution conditions need to be explored separately, and the recovery rate and reproducibility of lead cannot be guaranteed. Even new pollution (such as newly added coprecipitant, eluent, etc.) will be introduced; this is difficult to achieve for the separation and enrichment of ppb level (ng / mL) lead with very trace content itself ; If the sample types are quite different and the matrix is ​​complex, it is more difficult to ensure the separation and enrichment effect

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