[Determination of trace arsenic in soy and vinegar by catalytic oscillopolarography].

The determination of trace arsenic in soy and vinegar by oscillopolarography was investigated. A sensitive catalytic wave of arsenic appeared at -0.73V (vs. SCE) in 2mol/L H2SO4-0.2 mol/L KI-5 micrograms/ml Te systems. The linear relationship was 0-100ppb. The determination of arsenic in soy and vinegar was carried out after digestion with nitricperchloric acids. The detection limit was 1 ppb. The relative standard deviations were 4.7% and 8.8% respectively from the determinations of soy and vinegar. Recoveries were 92%-102% and 96%-110% respectively.