DETERMINATION OF MERCURY-VAPOR IN AIR USING ELECTRICALLY HEATED, GOLD-COATED WIRE-LOOPS, IN-TORCH VAPORIZATION SAMPLE INTRODUCTION AND INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY WITH PHOTODIODE-ARRAY DETECTION

A method for the determination of Hg-0 vapor in ambient air using an e lectrically heated, Au-coated wire-loop, in-torch vaporization (ITV) s ample introduction and inductively coupled plasma atomic emission spec trometry (ICP-AES) spectrometry with photodiode array detection is des cribed. Tungsten wire-loops were coated with gold using sputtering met hodology developed for scanning electron microscopy (SEM). Mecury vapo r formed an amalgam with Au on the wire-loop, the wire-loop was insert ed into a modified ICP torch about 10 cm below the plasma and electric al power was applied to the loop, thus thermally releasing mercury. At omic emission was monitored using an ICP spectrometer equipped with a photodiode array detector. Calibration curves were constructed using a variation of the reduction-aeration method and were linear for about two-and-a-half orders of magnitude. Mercury vapor levels determined cl ose to a polarography apparatus compared favorably with measurements t aken at the same location using cold vapor atomic absorption spectrome try (CVAAS). The possibility of using a Au-coated wire-loop system as an integrating personal dosimeter is postulated.