Express method of the quantitative determination of nitrites by computer colorimetry using new reagent compositions

The possibilities of using new reagent compositions based on diazo and azo dyestuff components that contain sulfonic groups are considered to determine nitrites in the presence of the contents of chlorides. New reagent compositions based on 1-hydroxynaphthalene-3,6-disulfonic acid in combination with 2,6- nitroorthanilic and 2,6-dichlorosulfanilic acids have been used to create indicator powders and indicator papers for the quantitative test determination of nitrite ions. Test methods based on sustainable indicator powders and indicator papers have been developed with the use of the ilPro portable spectrophotometer and PlustekSmartPhoto P60 compact mobile scanner combined with the Vuescan universal scan program. It has been shown that the sensitivity of the visual determination of nitrites in liquids using indicator papers is 0.5 mg/L. The sensitivity of the test method that uses indicator papers, the PlustekSmartPhoto P60 mobile scanner, and the ilPro portable spectrophotometer is 0.2 mg/L. Upon using the indicator powder and i1Pro portable spectrophotometer, the range of defined concentrations of nitrite ions is 0.01–5 mg/L.