Many instrumental techniques are used to monitor the quality of food products, highlighting near infrared spectroscopy (NIRS). In order to determine the authenticity of 60 commercial oil samples seized by the Espírito Santo state police, this work used a portable spectrometer in the NIR region associated with chemometric tools such as principal component analysis (PCA) and partial least squares regression (PLS) to classify and quantify possible adulterants present such as soybean oil. In addition, physicochemical tests (acidity, peroxide and ultraviolet absorption) were carried out on commercial samples. The PLS regression model built to quantify soybean oil showed a coefficient of determination (R2) greater than 0.99, showing itself to be satisfactory. The results showed that all samples analyzed had a high content of adulterant and cannot be classified as extra virgin olive oil.

Wax deposit is of a great concern in the petroleum industry and causes partial or total blockage of the pipelines. In this work, four Brazilian crude oils (P1-P4) and five inhibitors solutions (I1-I5) were used associating rheology results to understand, at a molecular level, the characteristics of the saturated fractions by high-resolution mass spectrometry (Orbitrap coupled to atmospheric pressure chemical ionization (APCI) source) and two-dimensional gas chromatography coupled to mass spectrometry (GC × GC-MS). The effectiveness of wax inhibitors can be demonstrated by the viscosity decrement. The characterization of the saturated fractions by GC × GC-MS and high resolution mass spectrometry showed that is possible to conclude that inhibitor I1 favored the inhibition process of paraffins when oils have a smaller and monocyclic saturated chain hydrocarbon (HC) profiles, whereas for oils with larger amounts of polycyclic chain HCs, the inhibitor I4 appeared to be the alternative.

It has been recurring adulterations in fuels (such as gasoline, ethanol and diesel), being necessary the exploration of the use of more modern analytical techniques capable of controlling the quality of these fuels, since some regulated tests may be inefficient to detect the adulteration. Among them, it is highlighted proton nuclear magnetic resonance (1H NMR) spectroscopy, and portable near infrared spectroscopy (microNIR). In this work, it was studied the conformities of 115 samples of seized fuels (76 of gasoline, 23 of ethanol, and 16 of diesel) by means of standardized techniques with parameters established by the ANP. Results obtained were compared to photometer, MicroNIR and 1H NMR analyzes. The analyzes carried out by ANP showed four nonconforming samples (one of gasoline and three of ethanol). By the photometric technique, only 14 gasoline samples had ethanol content permitted by legislation (i.e ≈ 27 %v/v). By 1H NMR analysis, it was possible to verify nonconformities by presence of aromatics and olefins compounds in the gasoline and diesel samples as well as of methanol in fuel ethanol samples. It is also worth noting the efficiency of MicroNIR when combined with unsupervised chemometric methods to indicate nonconformities presented by 1H NMR and photometry techniques.