The catechol violet colour reaction for tin(IV) sensitised by cetyltrimethylammonium bromide

Abstract

The sensitivity of the colour reaction between tin(IV) and catechol violet has been greatly increased by the sensitising action of cetyltrimethylammonium bromide (ε_662mµ= 95,600). The sensitisation is also accompanied by a considerable bathochromic shift (107 mµ) of the wavelength of maximum absorption. Full colour development occurs within 5 minutes at pH 2·2, and Beer's law is obeyed down to 0·2 p.p.m. of tin(IV).