Chromatography Filter Paper
By simple chromatography on filter paper the levelling properties of a product for direct or reactive dyes can be checked in a very short time.
Preparation of the test :
A circular glass, i.e. a watch glass, (A) is filled up to the half with the same composition as the dye bath, but without the dyes.
The dyes (Yellow, Red and Blue plus a combination of Y, R and B ) are drawn on a quarter of a circle at about 2 cm. from the center (C) of a filter paper with 15 cm. * (B).
A piece of filter paper is twisted and inserted into the center (C) of the filter paper (A). The dyeing bath is then coming up by capillary through the center of the filter paper.
Reactive Red 195
Reactive Blue 19
Reactive Blue 21
Reactive Navy 1
The solutions are prepared at 10 %)
0 – 0,5. – 1 g/l of the tested product
Time for chromatography
From the moment the dyeing bath enters the center of the filter paper A at the point C the chromatography should run 20 minutes before taking away the filter paper C.
The first evaluation is visual but it is possible to prepare a diagram by measuring the distance from the center to the last ring observed on the filter paper.
Written By - Dr. Stef, CTO, Lorel Chemical co. Ltd, New York, USA