TRACE-ELEMENT LASER MICROANALYZER WITH FREEDOM FROM CHEMICAL MATRIX EFFECT

A study on the susceptibility of TABLASER—Trace (element) Analyzer Based on Laser Ablation and Selectivity Excited Radiation to various chemical interference effects has been carried out. Tests were made on a diverse range of chromium doped samples to study source interference; anion-anion interference; cation-anion interference, Ionization interference. The observed laser induced fluorescence signal was found to be relatively independent of the source materials used, even under conditions of doping with high concentrations of compounds such as copper sulfate and potassium sulfate. The calibration curves for chromium in three different matrix materials are linear with a 45° slope. These observations provide evidence that our TABLASER is relatively free from chemical interference effects. The absence of these undesirable effects is attributed to (a) the extremely high temperature of the laser generated plasma (enabling complete dissociation of the compounds) and (b) the subsequent rapid expansion of the laser ablated plasma into the low vacuum region (which minimizes molecular association through interspecies collisions). This new technique has the potential for development into a new form of laser trace element microanalyzer that could be used for in situ high sensitivity measurements. © 1979, American Chemical Society. All rights reserved.