CHIMIA (Oct 2001)
Access to Isotopic and Elemental Composition and Their Distribution in Solid Materials by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry
Abstract
Laser ablation-inductively coupled plasma-mass spectrometry is becoming a powerful analytical technique for in situ trace element determination and isotope ratio determination in solids.A number of fundamental studies using a 193 nm ArF excimer and a 266 nm Nd:YAG laser ablation system were carried out to study the wavelength-dependent ablation behaviour of different materials. New optical arrangements used for the laser beam delivery onto the sample surface and increased fluency at 266 nm show tremendously improved ablation characteristics of this wavelength, especially for highly transparent samples. The investigations indicate that sample removal is wavelength- and material-dependent.Fast signal acquisition using a new generation ICP-MS with 'Time-Of-Flight' mass analyser, permits more information to be obtained per sample run in respect to traditional scanning instrumentation. Especially when dealing with samples of small amount and large isotope menus, the capabilities of an ICP-TOFMS result in greatly improved time resolution.The complex matrix introduction in laser ablation leads to a number of interferences, which were studied using the recently introduced dynamic reaction cell technology in ICP-MS. Gas reactions using hydrogen allow argides to be removed, while maintaining the multi-element capabilities of ICP-MS. A comparison of standard mode and DRC indicates excellent agreement between both modes of operation and demonstrates the potential of this technique for trace element analysis.
