AFS Determination of Trace Amount of Hg in Lead-Zinc Ore by Response Camber Optimization

AFS was applied to the determination of trace amount of Hg in lead-zinc ore by response camber optimization. Based on the designing by the Plackett-Burman testing of 10 factors in AFS of Hg, i.e., volume of mixed acid of HCl-HNO3(3+1), mass concentration (ρ) of reductant, flow-rate of auxiliary gas, time and temperature of digestion, volume fraction (φ) of carrying current, temperature of atomizer, negative high voltage of photomultiplier, lamp current and flow-rate of carrying gas, the first 3 factors were found to be the significant ones; giving their optimum values of 10 mL, 0.3 g·L-1 and 450 mL·min-1 repectively found by optimization of the 3 factors through central composite designing. Linearity range of Hg was found in the range within 10.00 μg·L-1. The proposed method was applied to the analysis of 3 CRM′s of GBW 07165, GBW 07162 and GBW 07163, giving results in consistency with the certified values and values of RSD′s (n=6) found from the analytical results were in the range of 0.38%-5.5%.