“…A number of analytical techniques are available ranging from simple density measurements to modern techniques such as gas chromatography/ mass spectroscopy for identification of adulterants. The common testing methods for the fuels are density measurements, rate of evaporation, ash content determinations and viscosity measurements (Kalligeros et al, 2003), optical sensors (Bahari et al, 1992;Roy, 1999), spectroscopic methods (Canizares & de Castro, 1996;Patra & Mishra, 2001a,b, 2002Lima et al, 2004;Divya & Mishra, 2007;Al-Ghouti et al, 2008) and chromatographic (Pedroso et al, 2008) fingerprinting methods. Inclusion of different marker compounds such as dyes to the fuels can also be utilized for investigation of the levels of adulterants.…”