Dye and dye intermediates have applications in paints, inks, textiles, paper and plastic industry. They are used as raw material for direct dyes, acid dyes and reactive dyes. India is a major exporter of synthetic and organic dyes.
Dyes are classified into many types such as acid dyes, basic dyes, direct dyes, disperse dyes, azo dyes, and sulphur dyes etc.
Dyes are susceptible to adulteration hence it becomes mandatory to analyse dyes.
HPTLC being a versatile technique proves to be just the right analytical tool to analyse without much hassle. Dyes are non-volatile organic substances and so best suited for HPTLC analysis.
One such example of dyes analysis by HPTLC is comparison between the formulation and the dyes used in it.
Here disperse dyes formulation was compared with standard dyes used in the commercial product. Disperse orange 288, Disperse Orange 61, Disperse violet 93.1 and disperse blue 291.1 along with the formulation were applied on HPTLC plate. The plate was developed in Toluene: Acetone (7:3) v/v mobile phase. The plate was air dried for 5 minutes and observed under white light in visualizer.
It was found that the disperse dyes were present in the formulation. The time required to develop this method was 2-3 days including some trials. Hence, we can conclude HPTLC instrumentation to be a versatile chromatographic technique.