TY - JOUR KW - Deposition KW - Temperature KW - Measurements KW - Measurement KW - USA KW - Surface KW - Ablation KW - Laser KW - Laser ablation KW - Laser ablation KW - Vaporization KW - Oxide KW - Time KW - Beam KW - Ca KW - E KW - Element KW - Fractionation KW - Glass KW - Glasses KW - Icp-ms KW - Inductively coupled plasma (icp) KW - Inductively coupled plasma mass spectrometry KW - Inductively-coupled plasma KW - Mass KW - Mass spectrometer KW - Mass spectrometry KW - Mass spectrometer KW - Mass spectrometry KW - Plasma KW - Plasma mass spectrometry KW - Plasma-mass spectrometry KW - Sample KW - Sampling KW - Spectrometer KW - Spectrometry KW - Lasers KW - Ratio KW - Single KW - Crater KW - Lam-icp-ms KW - Nd:yag KW - Elements KW - Ratios KW - 266 nm KW - Nd:yag laser KW - Nm KW - Correlation KW - Laser ablation sampling KW - Laser beam KW - Melting KW - 213 nm KW - Nist KW - Wavelength KW - Crater geometry KW - Depth KW - Microanalysis KW - Nd KW - Wavelengths KW - Yag KW - Glass samples KW - Elemental fractionation KW - Geochronology KW - Irradiance KW - Laser wavelength KW - Laser-wavelength KW - Pb/u KW - Temperatures KW - Zircon AU - Haichen Liu AU - Oleg V Borisov AU - Xianglei Mao AU - Stephen Shuttleworth AU - Richard E Russo AB -

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.

AD -

Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA Chinese Acad Sci, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China

BT - Applied Spectroscopy C2 - LBNL-46626 DA - 10/2000 IS - 10 LA - eng LB - Laser M1 - 10 N2 -

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.

PY - 2000 SP - 1435 EP - 1442 T2 - Applied Spectroscopy TI - Pb/U fractionation during Nd : YAG 213 nm and 266 nm laser ablation sampling with inductively coupled plasma mass spectrometry VL - 54 ER -