INFLUENCE OF GAS ENVIRONMENT ON PICOSECOND LASER-ABLATION SAMPLING EFFICIENCY AND ICP CONDITIONS

The effects of gas atmosphere on inductively coupled plasma excitation characteristics and picosecond laser ablation sampling are studied fo r enhancing atomic emission spectroscopy sensitivity. Five noble gases (He, Ne, Ar, Kr, Xe) were used in the laser ablation sampling chamber . The noble gases significantly influence the ICP excitation character istics and the laser ablation sampling efficiency. There is an enhance ment in ICP emission intensity for laser sampling in He and Ne and a d ecrease for Kr and Xe relative to Ar. Plasma shielding is a possible m echanism to explain the gas effects, as the behavior of laser sampling correlates with the ionization potential of the gas, The significant improvement in AES using He as the sample chamber gas is beneficial to chemical analysis, especially for trace analysis, which requires high sensitivity.