极谱催化波法测定苯甲醛

摘要

在磷酸盐缓冲溶液中，苯甲醛与联氨反应生成的产物苯甲醛腙在K2S2O8存在时于-1.22V(vs.SCE)产生一灵敏的极谱催化波。基于此，拟定了测定痕量苯甲醛的新方法。在8.0×10-2 mol/L KH2PO4-NaOH（pH8.0±0.2）-2.5×10-2 mol/L联氨-3.5×10-2mol/LK2S2O8底液中，极谱催化波峰电流与苯甲醛浓度在1.0×10-9～6.2×10-8 mol/L范围内呈线性关系，比无K2S2O8存在时灵敏度提高约60倍。本方法适用于生活污水中苯甲醛含量的测定。%Benzaldehyde was quickly derived to benzaldehyde hydroz one withNH2.NH2 in phosphate buffer solution. The reduction wave of benzal dehyde hydrozone at -1.22V (vs.SCE) was catalyzed by K2S2O8, which pr oduced a polarographic catalytic wave. A new method for the determination of trace of benzaldehyde was proposed. In 8.0×10-2 mol/L KH2PO4-NaOH (pH8.0±0.2)-2.5×10-2 mol/L N2H4-3.5×10-2 mol/L K2S2O8 mol/L buffer solution, the second order derivative peak current of the catalytic wave was linearly proportional to benzaldehyde concentration in the range of 1.0×10-9～6.2×10-8 mol/L(r=0.998). The sensitivity of the catalytic wave was 60 times higher than that of the corresponding reduction wave. The method was used to determine benzaldehyde in domestic sewage.