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An Improved Technique for Spot Testing, using a ‘Cellophone’ Membrane


IF the coloured compound in a spot test is allowed to form within a ‘Cellophane’ membrane instead of on filter paper, the colour can be seen much more clearly, and colour comparison is greatly facilitated. The procedure is described below for the formation of salicyloylhydrazones by aldehydes and ketones1, but is of general application.

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  1. 1

    Camber, B., Nature, 174, 1107 (1954).

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