Abstrakt
Photochemical vapor generation of tellurium was accomplished in a simple reactor consisted of a polytetrafluorethylene reaction coil wrapped around a low-pressure mercury bench lamp. The volatile species were generated using a flow-injection system.
The composition of a reaction medium, the influence of irradiation time and the effect of sensitizers and interferents were investigated using a miniature diffusion flame atomizer and high-resolution continuum source atomic absorption spectrometry. Combination of 5 mol L(-1) acetic acid and 3.5 mol L(-1) formic acid in the reaction medium, the addition of 15 mg L(-1) Fe(2+) and 250 mg L(-1) Mn(2+) as sensitizers in a sample and a flow rate of 4 mL min(-1) (corresponding to an irradiation time of 28 s) were found optimal for photochemical vapor generation.
A limit of detection of 3.2 μg L(-1) and repeatability of 2.4% at 500 μg L(-1) were achieved. Photochemical vapor generation efficiency of 50+-2% was determined from a relative comparison of sensitivities obtained with photochemical vapor generation and liquid nebulization, both coupled to inductively coupled plasma mass spectrometry.