离子色谱法同时测定水中总氮和总磷

采用碱性过硫酸钾消解—离子色谱法同时测定水中总氮和总磷的含量。该方法避免了国标法中过硫酸钾和氢氧化钠对吸光度的干扰,对总氮和总磷测定的精密度有很大的提高。该方法在实验测定的浓度范围内总氮和总磷的相对标准偏差分别为3.84%和4.24%;总氮和总磷的最低检出限分别为0.007 mg/L和0.009 mg/L,比国标法更低;对实际试样总氮和总磷的加标回收率分别为92.6%～105.3%和94.7%～100.2%。

Simultaneous Determination of Total Nitrogen and Total Phosphorus in Water by Ion Chromatography

The contents of total nitrogen and total phosphorus in water were simultaneously determined by the method of alkaline potassium persulfate digestion-ion chromatography.This method can avoids the interferences of potassium persulfate and sodium hydroxide on absorbance,which often occur in the national standard method.The accuracies of total nitrogen and total phosphorus determinations are greatly improved.In the concentration range of the experiment,the relative standard deviations of total nitrogen and total phosphorus are 3.84% and 4.24% respectively,and the detection limits are 0.007 mg/L and 0.009 mg/L respectively,which are lower than the national standard method.The recoveries of standard additions for total nitrogen and total phosphorus in actual samples are 92.6%-105.3% and 94.7%-100.2% respectively.