USE OF INTERNAL STANDARDIZATION TO COMPENSATE FOR A WIDE-RANGE OF ABSORBENCY IN THE ANALYSIS OF GLASSES BY UV LASER-ABLATION INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY

A frequency-tripled Q-switched Nd:YAG laser (355 nm, 10 Hz, 5 mJ per s hot, Surelite, Continuum) was used for the ablation of glasses as dire ct solid sampling for inductively coupled plasma atomic emission spect rometric multichannel detection. The colored and transparent glasses w ere glass standards used for calibration in ii-ray fluorescence spectr ometry and exhibited a 0.15-3.5 absorbance range at 355 nn. Translatio n of the target (1 mm s(-1)) with respect to the laser beam was used o ver a length of 16 mm. The depths and widths of the corresponding patt erns were not related to the absorbance of the samples. However, the a nalytical Line intensities were efficiently compensated for by using t he Si(I) 251.611 nm line as an internal standard. The repeatability wa s therefore improved for Na, K, Ca, Mg, Sr, Ba, Zn, Pb, Al, Fe, and Sb , as well as the correlation coefficients of the regression and the ce ntroid uncertainties of the calibration graph. Preliminary investigati ons were carried out to evaluate the acoustic signal emitted by the mi croplasma as external standardization. However, a negative correlation was found with the Line intensity signals under our operating conditi ons.