Calibration graphs for steels by IR laser ablation inductively coupled plasma atomic emission spectrometry

Abstract

Infrared laser ablation (IRLA) was studied as a sample-introduction technique for the analysis of steels by inductively coupled plasma atomic emission spectrometry (ICP–AES). A comparison of two IRLA–ICP–AES systems based on Q-switched nanosecond Nd : YAG lasers was performed. The beam of the Lina-Spark atomizer (LSA Sarl, Cully, Switzerland) based on the Surelite I-20 laser (Continuum, USA) was moved along a circle. A Perkin–Elmer Optima 3000 DV ICP system was used both with lateral and axial viewing modes. A laboratory-made ablation system based on the Brilliant laser (Quantel) was coupled to a Jobin-Yvon 170 Ultrace ICP (lateral viewing, polychromator part employed). A sample was rotated along a circle during ablation. Linearity of calibration plots was verified at least up to 19% Cr and 12% Ni without internal standardization for both LA–ICP–AES systems. Other elements examined were Mo up to 3%, Mn up 1.5%, Si up to 1.7%, and Cu up to 0.15%. The reproducibility was in the range 5–1 %RSD for a mass percentage 0.5–20% of steel constituents. The relative uncertainty of the centroids of the calibration lines was in the range from ± 4% to ± 12% for Cr, Ni, Mn, Mo, and Si, and from ± 8% to ± 19% for Cu. The lowest determinable quantities were calculated for calibration dependencies. Performances of both the IR-LA–ICP–AES were comparable.