NEW UNIVERSAL QUARTZ BURNER FOR DECOMPOSITION OF SAMPLES BY THE WICKBOLD COMBUSTION TECHNIQUE IN DETERMINATION OF ARSENIC, ANTIMONY, SELENIUM, MERCURY, AND LEAD

A new universal quartz burner for the Wickbold decomposition method is investigated with respect to its fast and efficient decomposition of solid samples for determining volatile trace elements like arsenic, an timony, selenium, mercury, and lead. Decomposition is based on burning samples in an oxyhydrogen flame, The samples are transported into the flame in gaseous form by pyrolyzing the material in an oven heated to 1100 degrees C. During this decomposition step, a nitrogen stream loa ded with carbon tetrachloride mobilizes the volatile elements, causing separation from the sample matrix. An effective precombustion in oxyg en and a large turbulent flame improve decomposition conditions. Diffe rent certified inorganic and organic reference materials are pyrolyzed and combusted, and the combustion products are absorbed in water. Met als found in the absorption solutions are analyzed by flow injection/h ydride generation/atomic absorption spectrometry. Data were analyzed b y several statistical tests recommended for quality control purposes. The combination of a decomposition and detection method resulted in ve ry low detection limits: 1.4 mu g arsenic/kg, 0.8 mu g antimony/kg, 1. 8 mu g mercury/kg, 1.4 mu g lead/kg, and 1.6 mu g selenium/kg can be d etected without an extra enrichment step.