海水中总氮的测定方法比较研究

通过标准曲线、检出限和测定范围、方法精密度、方法准确度、实际海水样品测定结果、加标回收率、分析效率和物料消耗这几方面比较了过硫酸钾氧化法、流动注射分析法和高温氧化-化学发光检测法这3种测定海水中总氮(TN)方法的优缺点。结果表明,流动注射分析法和高温氧化-化学发光检测法的测定范围更宽,精密度、准确度更好,3种样品的加标回收率达到96.2%~101%;高温氧化-化学发光检测法分析效率高、物料消耗少、节能环保,适用于一般海水样品的批量分析,且由于测定范围大,该法也适用于TN浓度较高的海水样品的批量分析,流动注射分析法因其较低的检出限更适用于TN浓度较低的海水样品的批量分析。

Comparative Study on Determination of Total Nitrogen in Seawater

The potassium persulfate oxidation, flow injection analysis, and high temperature oxidation chemiluminescence detection methods were compared from the standard curve, detection limit and measurement range, method precision, accuracy test, actual seawater sample determination results, determination of recovery rate, analysis efficiency and material consumption. The experimental results indicated that, the measurement range of flow injection analysis and high temperature oxidation chemiluminescence detection were wider, the precision and accuracy were better, and the spiked recoveries of the three samples were between 96.2% and 101%. The high temperature oxidation chemiluminescence detection method had high analysis efficiency, low material consumption, energy saving and environmental protection, but it showed high detection limit, so it was more suitable for the analysis of bulk seawater samples with higher total nitrogen content. Flow injection analysis was more suitable for the analysis of bulk seawater samples with lower total nitrogen content because of its lower detection limit.