方波阳极溶出伏安法测定区分溶解态与胶体态铅

DISTINGUISHING BETWEEN DISSOLVED ANDCOLLOIDAL LEAD BY SQUARE WAVE ANODICSTRIPPING VOLTAMMETRY METHOD

本文对在赤铁矿胶体存在下用方波阳极溶出伏安法测定区分溶解态和胶体态铅进行了研究。赤铁矿胶体的存在对铅离子的电化学测定没有影响。赤铁矿胶体存在时测得的铅峰电流随振荡时间、ｐＨ及加入铅浓度的变化与经典的通过分离固液相方法测得的铅在赤铁矿上的吸附动力学曲线、吸附ｐＨ曲线及吸附等温线的规律一致，峰电流反映的是溶液中铅离子的变化。赤铁矿胶体的铅滴定曲线类似于溶解配体的滴定曲线。

Square wave anodic stripping voltammetry met hod to distinguish dissolved and colloidal lead in presence of hematite colloid was studied. Hematite colloid was found to have no effect on the electrochemical determination of the lead ion. The variations in peak current with shake time, pH and added lead concetration of presence of colloid were consistent with adsor ptive dynamic curve, pH curve and isotherm by separating solid and liquid phases method. The peak current variation reflected the change of lead ion in solution . The titration curve of hematite colloid suspension with lead ion is similar to that of dissolved ligand. So we can determine the adsorptive capacity of colloi d suspension by eletroanalytical mehtod.