【摘要】 拟定了在小体积容量瓶中,在KBr存在下,以Fe（Ⅱ）作还原剂,用甲苯作萃取剂,从7.5mol/LH₂SO₄介质中一次性还原萃取砷,再用0.2mol/L KI（pH=9碳酸盐缓冲液）先质溶液一次性反萃取,然后用电生Ⅰ₂作库仑滴定剂,电位法检测终点测定砷的方法。检测限为0.5μg/25mL,测定1～20μgAs（Ⅲ）,回收率为100±10％,应用于矿石分析,结果与经典比色法相符。本法还可应用于钢铁分析。更多还原

【Abstract】 In the presence of KBr, using Fe（（?）） as reductant and toluene as extractant, the covalent complex of As（Ⅲ） with HBr was extracted from 7.5mol/L H₂SO₄, then backextracted into 0.2mol/L KI（pH9, buffer by carbonate） from toluene phase in small volumetric flask and followed by determination of As（Ⅲ） by coulometric titration. The detection limit is 0.5μg As/25ml. The recovery is 100±10% in the range of 1—20μg/25ml. The method has been applied to the determination of arsenic in ores. The results agree well with those by the colorimetric method. It is also applicable to analyses of alloy steels.更多还原