间隔流动分析法测定水中总磷

采用间隔流动分析法(SFA)测定地表水和城镇污水处理厂废水中的总磷,并与现行国标方法作比对,发现悬浮物对SFA法的结果存在一定的干扰,并对此进行了详细讨论且设计了一系列实验。实验结果表明使用均质机对水样均质能够有效消除悬浮物对测定结果的影响。水样经均质处理后两种方法测定结果相对误差小于3.0%。SFA法绘制的校准曲线线性大于0.999 5,标准样品的平行测定RSD≤1.5%,方法检出低限为0.009 mg/L,地表水样品加标回收率为91.4%～97.7%。

Determination of Total Phosphorus in Water by Segment Flow Analysis

The total phosphorus in surface water and water of urban sewage treatment plant were determined by SFA. To compare with the GB method, the interference of suspended substances was founded while some discussion and experiment about such interference were made. The result showed that the usage of viscolizer, which was used for sample homogenization, was able to deal with such interference effectively. The relative differences between the two methods after homogenization were below 3.0%. The linearity of the SFA method calibration was above 0. 999 5. The RSD of parallel standard sample was no more than 1.5%. The detection limit of the method was 0. 009 mg/L. Spiked recoveries of surface water were between 91.4% and 97.7%.