A simple in situ visual and tristimulus colorimetric method for the determination of diphosgene in air

A simple visual and tristimulus colorimetric method (three-dimensional system CIE–L*a*b*) for the determination of trace amounts of diphosgene in air has been developed. The method is based on the suction of diphosgene vapors through a modified cotton fabric filter fixed in a special adapter. Prior...

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Bibliographic Details
Published in:Journal of the Serbian Chemical Society 2007-10, Vol.72 (10), p.1031-1037
Main Authors: VLADIMÍR PITSCHMANN, ZBYNĚK KOBLIHA, EMIL HALÁMEK, IVANA TUŠAROVÁ
Format: Article
Language:English
Subjects:
4-(p-nitrobenzyl)pyridine
air analysis
diphosgene
N-phenylbenzylamine
tristimulus colorimetry
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Summary:A simple visual and tristimulus colorimetric method (three-dimensional system CIE–L*a*b*) for the determination of trace amounts of diphosgene in air has been developed. The method is based on the suction of diphosgene vapors through a modified cotton fabric filter fixed in a special adapter. Prior to analysis, the filter is saturated with a chromogenic reagent based on 4-(p-nitrobenzyl)pyridine. The optimal composition of the reagent is 2 g of 4-(p-nitrobenzyl)pyridine and 4 g of N-phenylbenzylamine in 100 ml of a 50:50 ethanol–glycerol mixture. The intensity of the formed red coloration of the filter is evaluated visually or by a tristimulus colorimeter (LMG 173, Lange, Germany). The detection limit is 0.01 mg m-3. Acetyl chloride and benzoyl chloride react in 150 and 50 times higher concentrations, respecttively. The method is suitable for mobile field analysis.
ISSN:0352-5139