title: Determination of benzene in gasoline using direct injection-mass spectrometry.
abstract: A high-speed determination of benzene in gasoline samples using a non-separative method based on direct injection into the mass spectrometer is proposed. The results obtained are very similar to those provided with fast GC-MS. The calibration set was made up of gasoline samples in which the benzene was determined chromatographically and samples of gasoline subjected to a process of evaporation--until the complete disappearance of the original benzene--to which known concentrations of this compound had been added. A PLS1 multivariate calibration model was constructed. Cross-validation was used to select the optimum number of PLS components. The prediction capacity of the model was checked with an additional group of gasoline samples that had not been used either in the construction or in the validation of the model. With the direct injection method proposed here it was possible to analyse 24 samples over a period of 1h. The direct injection method is rapid, simple and--in view of the results--highly suitable for the determination of benzene in gasoline samples.
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain. jlpp@usal.es
authors.forename: José Luis
authors.initials: JL
authors.lastname: Pérez Pavón
authors.forename: Miguel
authors.initials: M
authors.lastname: del Nogal Sánchez
authors.forename: Maria Esther
authors.initials: ME
authors.lastname: Fernández Laespada
authors.forename: Carmelo
authors.initials: C
authors.lastname: García Pinto
authors.forename: Bernardo
authors.initials: B
authors.lastname: Moreno Cordero