一种改进的水中总氮的快速消解方法

An improved method for rapid digestion and detection of total nitrogen in water samples

为了改进总氮测定的国标法,研究建立一种采用COD消解仪与旋盖式玻璃比色管测定水样中总氮的新方法.结果表明:方法最佳消解条件为120℃,50 min.相较于国标法,该方法测量空白值小(P <0. 001)、精密度(RSD=0. 935%)和准确性(P <0. 05)更高;试剂使用量为国标法的1/5,消解时间为国标法的1/2,尤其对总氮低浓度水样测定更准确.该方法在保证测量准确度和精密度前提下简化了实验步骤、节省了试剂用量、缩短了测定时间,可推广运用于一般水质的快速测定工作中.

An improved method of determining total nitrogen in water was introduced by using a COD digestion heater and closed glass colorimetric tube. The results showed that the water samples could be digested at least 120 ℃ for 50 minutes. This new method had a better precision( RSD = 0. 935%) and accuracy( P < 0. 05) compared with the national standard method,especially when water samples had low concentration of total nitrogen. This new method simplifies the experimental steps,saves the reagent dosage,and shortens the measurement time under the premise of ensuring measurement accuracy and precision. The new method can be used to measure the rapid determination of total nitrogen in water.