Influence of temperature on laser ablation fractionation during ICP-MS analysis for 213 nm and 266 nm laser wavelength micro-sampling
The influence of sample temperature on fractionation during ns-laser ablation of glass and lead samples was investigated. The 3rd and 4th harmonics of Nd : YAG lasers (266 or 213 nm) were used for sampling of solids: (i) at room temperature (c.a. 21 °C); (ii) at the temperature of dry ice (c.a. −77 °C). Fractionation, calculated for a glass reference material (SRM NIST 610) as the ratio of U/Th signals, decreased from 1.29 to 1.03 if the sample was kept at the low temperature during the entire time of analysis. Metal, as a good conductor, allowed for even more effective transfer of heat from the ablation spot. A distinct improvement of precision and accuracy of the results for the lead reference material PG-1 was observed.