Extractive Spectrophotometric Method for the Determination of Hydrogen Cyanide in Environmental Samples Using 4-Amino Salicylic Acid

Abstract A new spectrophotometric determination of the widely used fumigant hydrogen cyanide in air is described. The method is based on Konig reaction. The hydrogen cyanide from air is collected in a dilute solution of sodium hydroxide, brominated and reacted with pyridine to form glutaconic aldehyde. This is coupled with 4-aminosalicylic acid to form a yellow orange polymethine dye, which is extractable in n-butanol. The extracted dye shows an absorbance maximum at 520 nm. Beer's law is accomplished in the range of 0.03 to 0.2 mg 1−1. The application of the method for the analysis of hydrogen cyanide in cigarette smoke, cysteine and blood plasma is reported.