Improvements to the nitrite-diazo dye (Blom's) method of determining hydroxylamine as used in the determination of residues of aldicarb

Abstract

The precision of determination of hydroxylamine, and hence of residues of aldicarb, by Blom's method has been improved by controlling the pH of the solutions at the diazotisation and coupling stages and by removing the excess of iodine, after oxidation of the hydroxylamine, by extraction into bromobenzene. The latter previously required chemical reduction to iodide.