Pb/U fractionation during Nd : YAG 213 nm and 266 nm laser ablation sampling with inductively coupled plasma mass spectrometry

Publication Type

Journal Article

Date Published

10/2000

LBNL Report Number

LBNL-46626

Abstract

Elemental fractionation during laser ablation sampling was investigated by measuring Pb/U ratios in NIST 610 synthetic glass. Two Nd:YAG lasers with wavelengths of 213 and 266 nm were used to ablate the sample into an inductively coupled plasma mass spectrometer. Pb/U fractionation was observed to be similar for both laser wavelengths, and dependent on the irradiance. For representative Pb/U measurements, the necessary laser irradiance should be >0.6 GW/cm2. However, if the laser beam is initially focused close to the sample surface, fractionation increases and is influenced by the formation of a crater during repetitive pulsing at a single sample location. As the ratio of crater depth to radius increases, plasma sampling and/or an effective irradiance decrease could cause additional fractionation. A good correlation was found between the fractionation of 14 elements in NIST 610 glass and the logarithms of their oxide melting temperatures.

Journal

Applied Spectroscopy

Volume

54

Year of Publication

2000
1435

Issue

10

Pagination

1435-1442