双波长浊度补偿法测定水中总磷

Determination of Total Phosphorus in Water by Dual Wavelength Turbidity Compensation Method

采用钼酸铵分光光度法检测水质总磷时,检测结果极易受水中浊度的影响,针对此问题研究了一种双波长法来减小浊度的干扰,用待测溶液490 nm波长处的吸光度来补偿700 nm波长处的吸光度。实验结果表明,补偿后消除了浊度对总磷检测的影响,检测结果的相对误差缩小到5%以内,且操作简单,适用于水中总磷在线检测装置。

The value of total phosphorus tested by ammonium molybdate spectrophotometric method was frequently affected by water turbidity. Thus, a dual wavelength method was researched to reduce the turbidity interference by using the absorbance of the solution at 490 nm to compensate the absorbanee at 700 nm. The results indicated that the turbidity effect in total phosphorus detection was eliminated effectively and the relative error was reduced to 5%. The method was simple and adapted to on-line detection device for total phosphorus in water.