The Research On Interface Plasma-extraction Progress In ICP-MS

The mass spectrometer is a strong tool for material analysis. Inductively coupledplasma mass spectrometry(ICP-MS) is the high-end instrument with the highestsensitivity among all the mass spectrometers, it stands on the important position intrace and ultra-trace analysis and has an increasing great potential because of today sfood and environment safety issues. As a result, the research and development ofICP-MS with our own property has been put on the agenda.Based on the major national scientific equipment developed special project ICP-MS trace analysis instrument Development and Application, this paper is fromthe sub-project ICP-MS extraction interface, ion transportation and other keycomponents developments which discussed the plasma state changes in the extractionprogress and constituted the mainline of this paper. It completed the work as bellow:1. The structure of ICP-MS, the generation mechanism of plasma and the state ofplasma from torch were discussed, and the sampling cone plasma extraction modelwas established. Then, computational fluid dynamic(CFD) was intruduced to ICP-MSresearch, getting the related plasma physical state changes in interface cone regiondring the extraction progress, proving a research method for plasma extraction.2. Space charge formation mechanism and its impact on ICP-MS systemperformance were discussed firstly. Then the space charge distribution was calculatedand the related technology was provided to weaken space charge.3. With pressure and mass flux after skimmer as evaluation criteria, impact ofsampler structure parameters on plasma dynamics were discussed, comprehensivelyconsidering the sample signal sensitivity and matrix effects, optimaized samplerstructure parameters, providing the theoretical guidance for the sampler actual design.At last, summarized the content of this paper, pointed out the unresolved issuesand put forward the experimental solutions for the following work. Currently, the firstbatch of interface cones developed by ourselves was tested with good performance inthe aspects of sensitivity, matrix effect, and multi-ion interference. We have theconfidence that the first ICP-MS designed by China is available soon.