TABLASER - TRACE (ELEMENT) ANALYZER BASED ON LASER ABLATION AND SELECTIVELY EXCITED RADIATION

Trace element analysis based on laser ablation and selectively excited radiation (tablaser) is proposed as a new and reliable microultratrace technique for quantitative in situ element analysis. Measurements of trace quantities of chromium in samples of NBS standard reference steel, doped skim milk powder, and doped flour have been undertaken. A linear 45° slope dependence of signal vs concentration that extends beyond 1% in the case of chromium was observed. Although the present sensitivity limit is in the ppm range, improved overlap between the probing dye laser beam and the wave of atomized material combined with a better design of the optical system could reduce the detection limit of the tablaser to the ppb range. This would correspond to an absolute detection limit of about 10−16 g. An important feature of this new technique is its relative freedom from chemical matrix effects, which suggests the possibility of a unversal calibration curve for all elements irrespective of the substrate matrix in which they are contained. This technique is also adaptable to multielement analysis. © 1979 Optical Society of America.