紫外分光光度法测定结晶紫与SCN^-缔合物的稳定常数

UV-spectrophotometric determination of stability constant of EV-SCN^- ion-pairs

结晶紫是碱性染料,它是阳离子载体,与阴离子形成缔合物可作为PVC膜电极的电活性物质,电活性物质的溶度积(KSP)影响电极的响应性能。用紫外分光光度法测定了结晶紫与SCN-反应生成的缔合物的稳定常数,建立了测定缔合物稳定常数的方法,用紫外分光光度法测得该缔合物的稳定常数为7.0737×106,检测方法的相对标准偏差为1.98%。

As purples, ethyl violet are carriers of positive ions, they can react with negative materials of PVC matrix ion-selective electrodes, whose KSP values affect the respone nature of electrodes. The determination of ionic concentration in saturated solution of EV-SCN^- is studied by UV-spectrophotometry. Moreover ,the approach to the determination of the stability constant of ion-pair is introduced.The determination of the stability constant with UV-spectrophotometry is 7.0737×10~6, RSD is1.98% .