浊度滴定法  

Turbidity Titrimetry

作　　者：詹先成[1] 李成蓉[1] 钟术光[1] 李志毅[1] 林涛[1] 李琳丽[1] 

机构地区：[1]四川大学华西药学院,成都610041

出　　处：《分析化学》2002年第9期1112-1114,共3页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金资助项目 (No .39770 882 )

摘　　要：报道了一种实用的浊度传感器及浊度滴定仪 ,以及一种利用此仪器检测溶液的浑浊程度 (溶液中散射光相对强度 )来判断沉淀反应滴定终点的方法。将一束光线通入溶液 ,在溶液中与其垂直的方向上 ,利用内置浊度传感器检测散射光相对强度 ;随着滴定剂的加入 ,溶液将逐渐变得浑浊 ,散射光相对强度逐渐增强 ,如果沉淀反应完全且溶解度足够小 ,散射光相对强度将在化学计量点处达最大值 ,由此可判断滴定终点。以AgNO3 溶液滴定NaCl溶液为例验证了浊度滴定法 ,结果表明 :浊度滴定法较化学指示剂法适用于更低的浓度 ;在适当的条件下浊度滴定法的精密度和准确度均可 <0 .2 %。A turbidity sensor, a turbidity titrator, and a method to indicate the titration end-point of precipitation reaction by the measurement of the relative intensity of the scattered light in the titrate solution were introduced. A visible light-emitting diode (LED) was used as a light source and a photodiode was served as optical detectors. Light on the detectors created a current flow through the diodes. With the addition of the titrant, the titrate solution will be turbidness and the intensity of the scattered light in the solution will increase gradually. If the precipitation reaction proceeded completely and the solubility of the precipitation was small enough, the intensity of the scattered light could reach the maximum at the stoichiometric point; thus, the titration end-point could be indicated. The NaCl solution was titrated by AgNO3 solution as an example.

关 键 词：浊度滴定法 浊度传感器 溶胶 药物含量测定 散射光 

分 类 号：O657.3[理学—分析化学]