Thesis (M.Sc.)--Chulalongkorn University, 2006

The quantitative analysis of marker dyes from cardanol and nitro aniline in diesel using high performance liquid chromatography (HPLC) with UV-VIS detector was studied. The sample preparation was performed using silica column chromatography. The column was eluted with hexane and toluene, respectively. The quantitative determination of marker dyes was carried out suing C [subscript18] column (250 x 4.60) mm), methanol/0.2% acetic acid in water with ratio 95:5 as mobile phase, flow rate 0.80 mL/min, wavelength detection at 390 nm. Excellent linear coefficient of 0.9979 was obtained by constructed standard calibration in a range of 1.00-12.0 mg/L. Satisfactory method efficiency was evaluated from recovery and intra- and intermediate precision and the quantitation limit is 2.50 mg/L of marker dyes in diesel fuel. Moreover, the measurement of the amount of this marker dye in diesel stored for 3 months was studied. It was found that marker dye was stable in diesel. Therefore, the developed HPLC method can be used for quantitative determination of marker dyes from cardanol and nitro aniine in diesel with short analysis time, small volumes of sample, and provide quantitative measurement of marker dye to confirm qualitative measurement in the field test.