Soil heavy metal pollution quantification detecting system and detecting method

Abstract

The invention discloses a soil heavy metal pollution quantification testing system and the testing method, which is used to conduct quantification monitoring to medium and light heavy metal polluted soil. The quantification testing system of the invention comprises a laser, a beam splitter, a collecting optics lens, an optical fiber detector, optical fiber, a spectrograph, a laser dynamometer instrument and a computer. The quantification testing system of the invention normalizes the laser induction and plasma spectrum strength value of the trace element in soil standard sample into the strength value of injecting laser, and then utilized the linear relation between the normalized value and the element content to build calibrating plot, and finally utilizes the calibrating plot and the same normalization method to conduct quantitative detecting to the heavy metal element in the unknown soil sample.

Description

technical field [0001] The invention relates to a plasma spectrum quantitative analysis technology for substances, and specifically refers to a soil heavy metal pollution quantitative detection system and detection method, which are used for quantitative monitoring of moderately and lightly heavy metal polluted soil. Background technique [0002] Heavy metals are "a class of pollutants" in the environment. With the rapid development of social economy, the degree of pollution and the area of ​​pollution are increasing year by year. Once the soil is polluted by heavy metals, it will be enriched and magnified through the food chain and ultimately affect human health. Therefore, both domestic and foreign countries are very concerned about the monitoring and treatment of heavy metal pollution in soil. [0003] There are various types of soil heavy metal elements, and their background values ​​in the environment and the critical values ​​stipulated in the "China Soil Environmental...

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Problems solved by technology

[0007] In addition, when using laser-induced plasma spectroscopy for quantitative analysis, due to the small size of the sampling point (usually less than 1mm), the inhomogeneity of the measured sample matrix can easily lead to large dispersion of measurement results. In order to improve The precision and accuracy of quantitative analysis usually requires repeated measurements, which give ideal results based on statistical analysis of a large amount of data, but large measurement deviations are often introduced during each measurement process due to the instability of laser pulse energy , it is necessary to take necessary measures to eliminate this effect. The usual practice is to normalize the intensity value of the atomic spectral line of a specific element at a specific wavelength. The selection of the normalization standard directly determines the precision and accuracy of the quantification. Usually The normalization standard is selected as the signal intensity of a certain atomic line of the main element (element with higher content) in the sample. The starting point of this choice is that the atomic line intensity of the trace element and the atomic spectrum of the main element The relative relationship between the line intensities can maintain a good consistency in different measurement processes, but in fact, due to the inhomogeneity of the sample matrix, the content of the main elements also changes in each measurement process, and this change It cannot be quantified at all, so that the intensity of the atomic spectral line of the main element is also changing and cannot be quantified; therefore, when a variable and unquantifiable quantity is used as a standard value for normalization, the normalization result must also have a certain degree of The randomness will have an inevitable negative impact on the final statistical results

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