高压密封消解-流动注射同时测定海水中总氮和总磷

Simultaneous Determination of Total Nitrogen and Total Phosphorus in Seawater by High Pressure Sealed Digestion-Flow Injection

建立了高压密封消解-流动注射同时测定海水中总氮和总磷的方法,方法采用特制聚四氟乙烯密封消解罐,经高压消解锅消解后,用流动注射分析仪同时测定海水中的总氮和总磷。结果显示,总氮和总磷在0~3.20 mg/L范围内线性良好,总氮相关系数(r)=0.9997,检出限为0.012 mg/L,相对标准偏差为0.65%~2.59%,加标回收率为97.8%~102%;总磷相关系数(r)=0.9999,检出限为0.006 mg/L,相对标准偏差为0.50%~6.67%,加标回收率为98.8%~101%。该方法可同时测定海水中总氮和总磷,方法准确度和精密度良好,满足分析要求,适用于大批量海水样品中总氮和总磷的快速准确定量。

A method was established to simultaneously determine total nitrogen and total phosphorus in seawater by high pressure sealed digestion-flow injection.Samples were placed in a special polytetrafluoroethylene sealed digestion tank.After digestion in a high pressure digestion pot,the total nitrogen and total phosphorus in seawater were simultaneously determined by flow injection analyzer.The results showed that the linear equation of total nitrogen and total phosphorus was good in the range of 0~3.20 mg/L.Thecorrelation coefficient of total nitrogen was 0.9997,and the detection limit was 0.012 mg/L,and RSD value ranged from 0.65% to 2.59%,recovery rate was in the range of 97.5%~103%.The correlation coefficient of total phosphorus was 0.9999,detection limit was 0.006 mg/L,and RSD value ranged from 0.50%to 6.67%,recovery rate was in the range of 98.8% to 101%.The accuracy and precision of simultaneous determination of total nitrogen and total phosphorus in seawater have been improved,it is suitable for rapid and accurate determination of total nitrogen and total phosphorus in a large number of sea water samples.