Thesis (M.Sc.)--Chulalongkorn University, 2002

Synthetic xanthene dyes for marker in diesel could be classified into two groups. The first group is the hydroxyl derivative with increasing dissolvability in diesel oil by ether and ester-ether groups. The second group is the amino derivative which was obtained from dichloro compound by a reaction of hydroxyl group with amines. These synthetic marker dyes were added into diesel at concentrated levels of 300 to 900 ppm, and their presence could be separated and detected by separation on TLC plate in suitable solvent mixture. Quantitative measurement was carried out using spectrofluorometer. The testing results of fuel properties using the ASTM test methods revealed that the physical properties of the marked diesel were similar to those of the unmarked diesel oil. Moreover, those synthetic marker dyes were found to be stable in diesel oil for at least three months