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Li+在p H 10.5 B-R缓冲溶液中能抑制钙指示剂和H2O2形成络合物,1.0×10-4mol/L钙指示剂和1.2%的H2O2在0.16 mol/L的B-R缓冲溶液中,于起始电位-0.0 V(vs.SCE),峰电位(Ep)-0.628V(vs.SCE)处产生一灵敏的极谱还原波,Li+能与H2O2和钙指示剂结合使络合物的峰电流下降,该波的二阶导数峰电流(Ip“)与Li+质量浓度在0.8~800μg/m L范围内呈良好的线性关系,检出限为0.3146μg/m L。回收率为94.4%~102.9%。方法已用于碳酸锂片中Li+的测定,并讨论了其机理。电极反应物是钙指示剂和H2O2的络合物。
Li + can inhibit the formation of complex of calcium indicator and H2O2 in p H 10.5 BR buffer solution. 1.0 × 10 -4 mol / L Ca 2+ indicator and 1.2% H2O2 in 0.16 mol / L BR buffer solution were applied at the beginning Potential -0.0 V (vs.SCE) and peak potential (Ep) -0.628 V (vs.SCE) produce a sensitive polarographic reduction wave. Li + can combine with H2O2 and calcium indicator to reduce the peak current of the complex The second derivative peak current (Ip ”) of this wave has a good linear relationship with the mass concentration of Li + in the range of 0.8 ~ 800μg / m L with the detection limit of 0.3146μg / m L. The recoveries ranged from 94.4% to 102.9 %. The method has been applied to the determination of Li + in lithium carbonate tablets and its mechanism has been discussed. The electrode reactant is a complex of calcium indicator and H2O2.