Colorimetric method for determining small quantities of pyridine

✍ Scribed by Daroga, R. P. ;Pollard, A. G.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1941
• Weight: 376 KB
• Volume: 60
• Category: Article
• ISSN: 0368-4075
• DOI: 10.1002/jctb.5000600708

✦ Synopsis

Colorint el r ic 9) I dhotls Tlie colorinietric incthods were iiost csnniincd. The insoluble compound, Cu(C5H5N),(CNS),,B precipitated in Spncu's rcnction is soluble in cliloroforni to give n green solution suitnble for colorinietric deterniinntion. Experiments shoired tlint the precipitnte did not rendily dissolve in chloroform, but nppenred to be congitlnted by it. This method nppenrs to bo iiiore suitable for tletermining sniall qunntities of copper tlinn of pyridinc.

The ndditive compound of pyridinc nnd cynnogeu broniide rencts with nronintic nniines to forni iriteusely coloured clerivntires of glutnconnldehyde, nud tliis renction hns been utiliscd for the colorinictric deterniinntion by Iiulikor and I(rcstorosdrigensknjn.'? Anilinc and cynnogen bromide werc found by L o l ~i i c r ~~ nitd Goris nnd LnrsonnciiulJ to give the best results. Tlie difficulty of mnintnining supplies of freslily prepnred cynnogen bromide renders the method iniprnctirnlile for routine work. TAULE I Using 2 nil. of 1 : 4 tlilutivl rcngeut Tinic nfter Tintoiuctcr rcndingn Tciul'~.rntiire retliictiou B.