高效液相色谱法测定工业硝酸钾中痕量亚硝酸根离子

Determination of trace amounts of nitrite ion in industrial potassium nitrate by high performance liquid chromatography

根据亚硝酸根离子与格里斯试剂生成偶氮化合物的原理,建立了测定工业硝酸钾中痕量亚硝酸根离子的液相色谱分析方法.以对氨基苯磺酸和1-萘胺为原料配制格里斯试剂,利用亚硝酸根离子与对氨基苯磺酸重氮化后,再与1-萘胺偶联生成紫红色的偶氮化合物,采用液相色谱方法间接测定亚硝酸根离子的含量.实验结果表明,亚硝酸根离子质量浓度为1.0～100μg/L时,线性关系良好（r=0.999 7）,加标回收率均在99.00％-101.70％以上,相对标准偏差（RSD）低于2.5％（n=6）,最低定量限（LOQ）为1μg/L.利用该方法测定偶氮化合物的含量,间接地定量分析工业硝酸钾中含量低于0.000 1％的痕量亚硝酸根,该方法快速、精确、简便.

A high performance liquid chromatography for determination of trace amounts of nitrite ion in industrial potassium nitrate is established,based on the principle that azo compound can be generated by reaction of nitrite ion with Griess reagent.Sulfanilic acid and 1-naphthylamine are used as raw material for Griess reagent preparation.The purple azo compound is produced by diazotizing sulfanilic acid and reacting with 1-naphthylamine coupling.The nitrite ion content can be indirectly determined by using liquid chromatography indirectly.The results show that the linearity is good within the range of 1.0 μg·L-1-100 μg·L-1 （r =0.999 7） and the recoveries for the 3 samples are above 99.00％-101.7％.The relative standard deviations （n =6） are less than 2.5％.The lowest limit of quantitation （LOQ） was 1 μg· L-1.This method can indirectly perform the quantitative analysis on trace nitrite in industrial potassium nitrate with the content less than O.000 1％ by determining the content of azo compounds,which is rapid,accurate and simple.