Determination of naphthalene and total methylnaphthalenes in gasoline using direct injection-mass spectrometry

A high-speed determination of naphthalene and total methylnaphthalenes using a non-separative method based on direct injection into the mass spectrometer was performed. The results obtained for total methylnaphthalenes were very similar to those provided with fast gas chromatography–mass spectrometry (GC–MS). However, the non-separative method afforded higher concentrations in the determination of naphthalene than those found when fast GC–MS was used. We propose a correction that removes this error very satisfactorily and allows the same results to be obtained with both methodologies. The non-separative method is rapid, simple and – in view of the results – highly suitable for the determination of naphthalene and total methylnaphthalenes in gasoline samples.