Estimation method of residual alkylating agents in water treated with chloring-containing oxidant

Abstract

A sensitive method is described for estimating the residual alkylating agents in water after treatment with Cl-containing oxidants. The method is based on the reaction of 4-(p-nitrobenzyl)pyridine perchlorate (NBP · HClO₄) with alkylating agents to form a colorless quaternary salt which becomes red in certain organic solvents, such as benzine and toluene, following treatment with alkali. After the oxidants have been quantitatively destroyed by a mixture of NaNO₂ and NaHCO₃, small amounts of alkylating agent (e.g. 2,2′-dichlorodiethylsulfide and benzyl chloride) are detected or estimated by using NBP · HClO₄. The method can be used to detect and estimate ppm concentrations of alkylating agents. A recovery within 100 ± 10% has been generally obtained.