The total N in enviromental samples is commonly determined by K2S2O8-spectrophotometric method, and the total P is commonly determined by phosphatic molybdenum spectrophotometry.

• 摘要环境样品总氮的测定常用过硫酸钾氧化－紫外分光光度法测定，而总磷一般为磷铝蓝分光光度法。