氯离子选择性电极测定铁器碱性脱盐溶液中 氯离子的含量

在铁质文物的保护过程中,脱盐是重要的保护程序之一。通常铁器的脱盐溶液为碱性。本工作主要研究氯离子选择性电极法在测定碱性脱盐溶液中的氯离子含量时,溶液pH值和复配溶液中的表面活性剂对测定结果的影响。实验结果表明:(1)用氯离子选择性电极法测定碱性脱盐溶液或复配碱性脱盐溶液中的氯离子浓度是可行的;(2)溶液的pH值对测量结果有一定的影响,当溶液pH值在2～7范围内时,其对电位值影响不大;(3)表面活性剂对测量结果影响较小,在实际应用中,应配制与待测溶液组分相同的氯离子标准溶液,后期数据处理并绘制标准曲线,以使测量结果尽可能接近实际值。精密度和回收率实验表明,该方法准确度满足定量分析的要求。由此可见,当脱盐溶液为碱性NaOH或复配碱性NaOH溶液时,用氯离子选择性电极实时监测脱盐溶液中的氯离子含量能较好地反映器物脱盐程度。

Measuring chloride ion concentration in alkaline solutions by chloride specific ion electrode during treatment of corroded iron objects

In conservation of iron cultural relics , desalination is one of very important treatment. Generally , the de- salination solution is alkaline. In this study , the influence of various factors , such as pH value ,in alkaline desalina- tion solutions,on the chloride specific ion electrode were examined. These experiments showed that the pH value of the desalination solution affects the potential of chloride specific ion electrode , especially when the chloride ion con- centration is low. The optimal pH of the solution is between 2 and 7. The surfactant in the solution had no significant impact on the chloride specific ion electrode ,as seen in the fact that the potential value of the l# chloride standard solution( 0. 5 mol/L NaOH + 1. 5% DP - 105 ) was equal of that of 2# solution (0. 5 mol/L NaOH) . However, bothof them were higher than the potential value of 3# solution ( aqueous solution) . In practice , the components of chlo- ride ion standard solution should be the same as that of the solution to be tested. Using chloride ion standard solu- tions ,it was showed that when chloride ion concentration is between o and 200 mg/L , the standard curve was highly linear , reproducible , and precise , and had a high correlation coefficient.