The dlstnbutlon of 25 elements from Mg to U m the geologlcal materials,, stalactite and fossd shell were obtamed by laser ablation mductlvely coupled plasma mass spectrometry (LA-RIP-MS) The laser pulses m the free-running mode were fired several times at the same position while the samples were fured m each measurement The varlatlon of the slgnal intensity was normahzed usmg the 43Ca slgnal as the Internal standard, assummg that the CaCO, content IS 100% m every posdlon The standards were made from part of the samples themselves, whose elemental concentrations were determmed separately by solution method The analytlcal results by laser method for the mhomogeneous geological samples were assessed with those obtamed by solution analysis Keywords Inductively coupled plasma mass spectrometry, Geological materials,, Laser ablation, Microprobe analysis
Recently, direct mtroductlon of solids by laser ablation to the ICP for quahtatrve and quantltatlve analysis has been mvestlgated as a method of sample mtroductlon for ICP-MS [l-7] The laser method requires almost no sample preparation and has low levels of polyatomlc Ion Interferences which are normally derived from water and acrd However, there 1s a problem with the large vanatlon of analytical results which depends on the quality of the material and surface state This variation may be corrected for by using the signal of one of the elements analysed as the internal standard [2,3,5], or by evaluating the evaporated volume via measurement of the size of the laser shot crater [8] Hager showed that the relative sensltlvlty of the elements can be used for the semi-quantitative analysis [4] and Pang et al demonstrated that a lOO-Hz laser improved the reproduclblhty of the data [9]