Method of evaporating sample injecting inducted by dielectric barrier discharge microplasma

Abstract

The invention relates to a method of evaporating sample injecting inducted by dielectric barrier discharge microplasma. The method comprises steps that first a barrier discharge apparatus capable of producing microplasma is prepared, wherein the apparatus comprises a power, a switch, two insulating dielectric layers with concentric cylindrical pipe structure, two electrodes, an air inlet and a steam outlet; a discharge chamber is between the two dielectric layers, and an external electrode is covered outside the outer cylindrical pipe, and an inner electrode is inserted in the inner cylindrical pipe; and two electrodes are connected with the power; then a solution sample is added into a centrifuge tube, the inner cylindrical pipe of the dielectric barrier discharge apparatus is taken out and inserted into the centrifuge tube, and will be inserted back into the apparatus after sampling; carrier gas is let in, and the power is tuned on; the sample is absorbed by microplasma generated by dielectric barrier discharge; generated steam is purged by the carrier gas and enters a detector from the steam outlet, wherein the whole flow is finished in 90 s. The method is simply operated, without sample treatment, at low power dissipation, rapid and is especially suitable for analysis of small volume sample and trace and ultra trace elements.

Description

technical field [0001] The invention relates to an evaporation sampling method induced by dielectric barrier discharge micro-plasma. Background technique [0002] Sample introduction technology has always been a key issue in analytical chemistry, especially for the analysis of trace and ultra-trace elements in complex matrix samples. The efficiency of sample introduction significantly affects the analytical properties of an analytical method, such as sensitivity, precision, and robustness. [0003] Common sampling methods include pneumatic atomization, steam generation and electrothermal evaporation techniques. Pneumatic atomization sampling method has the advantages of simplicity, rapidity and good stability, but its sample introduction efficiency is low (<5%), and it is seriously interfered by the matrix. The vapor generation injection method significantly improves sample introduction efficiency (nearly 100%) and reduces matrix interferences. However, it is severely ...

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Problems solved by technology

However, it is severely interfered by transition metal elements (especially Ni, Co and Cu), and its injection efficiency depends on the chemical form of the analyzed elements

In addition, the reducing agent Na / KBH used 4 Expensive and unstable

Electrothermal evaporation sampling technology has the advantages of high sample introduction efficiency, less sample volume and direct analysis of liquid and solid samples, but it has high power consumption and poor reproducibility (>10% RSD)

[0004] Recently, dielectric barrier discharge microplasma has been used as an atomization source and desorption ion source, but there is no report on dielectric barrier discharge plasma as a liquid evaporation sampling method

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