Research Of Combination Technology Of193nm Laser-Ablation System And ICP-MS

Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) isbased on the laser ablation system (LA) and inductively coupled plasma massspectrometry (ICP-MS) combined with two new technology equipment. It has thein-situ, micro, rapid analysis and so on. The new LA-ICP-MS with zircon, silicateminerals, high uranium minerals monazite U-(Th)-Pb isotopic age analysiscapabilities, is an important research topic in today’s geology.In the laser ablation solid sampling systems, high-energy laser through the quartzwindow gathered at the sample surface, to promote the occurrence of local thermalgasification of volatile samples. Gasification of the sample flow rate through a certaincarrier gas (helium) is fed into inductively coupled plasma torch center tube.Frequency range of the laser pulse used is generally1-10Hz (is less than10times persecond, the number of erosion intermittent mode), and inductively coupled plasmamass spectrometer integration time of data points is usually10-50ms, close to thecontinuous mode. That is, when the laser ablation sampling pulse signal, inductivelycoupled plasma mass spectrometer detector response value (CPS record value) willincrease, and no pulse signal, the detector response value decreased, resulting in theerosion of the sample injection process in intermittent mode. The relative standarddeviation (RSD%) of LA-ICP-MS was significantly greater than the traditionalperistaltic pump to enhance the injection solution plasma mass spectrometry analysis(SN-ICP-MS), usually up to~10%, which greatly affect the data accuracy of theanalysis of solid samples.Currently Instruments standard way to connect is to use an inert1/8inchdiameter sample tube (polyethylene) laser ablation system directly into the plasmaflame aerosol generated by the center channel, did not consider sending twoinstruments differences in the modes with the received signal. Due to the above thetraditional not fully considering two existing collection/instrument signal output andthe time difference between, therefore the connection way significant influence on theLA-ICP-MS the accuracy of analytical results, restricted the LA-ICP-MS applicationfields.Based on the above LA-ICP-MS in the process of use of the problems found inthis study were put forward in LA with ICP-MS united way using gas, loading volumemix the vessels of the sample for solution. That means design to add a small glassvessels between laser ablation and inductively coupled plasma mass spectrometer, thevolume is about4-15mL, making the denudation of laser ablation can be gathered andmixture aerosol, before sent into inductively coupled plasma mass spectrometerdetection, and then sent into inductively coupled plasma mass spectrometer withcontinuous mode, so that achieve the effect of optimization, make inductively coupledplasma mass spectrometry analysis precision greatly increase, thus achieving theperformance optimization.