A. Bentley, J. F. Alder
1989
Citations
0
Influential Citations
22
Citations
Journal
Analytica Chimica Acta
Abstract
Abstract Hydrogen cyanide is detected by oxidation of the atmospheric sample with chloramine-T (sodium N -chloro-4-methylbenzenesulphonamide) impregnated on XAD-7 resin beads to yield cyanogen chloride. This reacts with 4-picoline (4-methylpyridine) and barbituric acid (pyrimidinetrione) also impregnated on XAD-7 beads, to yield a colour change with a maximum absorbance change around 530–565 nm. Using a modulated monochromated white light source and lock-in detector, the reagent system was able to detect HCN in air at 1 μl l −1 within 1 min. A flow- rate through the reagent cell of 60 ml min −1 air was chosen to give the best overall performance. Lifetime tests indicated a loss of 4-picoline due to evaporation, although reagent beads through which air was drawn at 100 ml min −1 for 66 h were still able to detect 10 μl l −1 HCN in less than 1 min. The method is not reversible and could not be used to monitor HCN concentration in air, but is nonetheless useful for the detection of HCN below its toxic level in a short time.