The effect of solvent grade on thin layer chromatographic analysis of writing inks.

The effects on the separation of writing ink dyes and the repeatability of the Rf values from using different grades of chemicals used in solvent system I (SSI) and solvent system II (SSII) for thin-layer chromatographic (TLC) ink analysis were studied. Solvent system I consists of a 70:35:30 mixture of ethyl acetate, ethanol, and water. Solvent system II consists of a 50:10:15 mixture of ethanol, water, and n-butanol.