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Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: The current legislation requires the mandatory addition of biodiesel to all Brazilian road diesel oil A (pure diesel) marketed in the country and bans the addition of vegetable oils for this type of diesel. However, cases of irregular addition of vegetable oils directly to the diesel oil may occur, mainly due to the lower cost of these raw materials compared to the final product, biodiesel. In Brazil, the situation is even more critical once the country is one of the largest producers of oleaginous products in the world, especially soybean, and also it has an extensive road network dependent on diesel. Therefore, alternatives to control the quality of diesel have become increasingly necessary. This study proposes an analytical methodology for quality control of diesel with intention to identify and determine adulterations of oils and even fats of vegetable origin. This methodology is based on detection, identification and quantification of triacylglycerols on diesel (main constituents of vegetable oils and fats) by high performance liquid chromatography in reversed phase with UV detection at 205nm associated with multivariate methods. Six different types of oils and fats were studied (soybean, frying oil, corn, cotton, palm oil and babassu) and two methods were developed for data analysis. The first one, based on principal component analysis (PCA), nearest neighbor classification (KNN) and univariate regression, was used for samples adulterated with a single type of oil or fat. In the second method, partial least square regression (PLS) was used for the cases where the adulterants were mixtures of up to three types of oils or fats. In the first method, the techniques of PCA and KNN were correctly classified as 17 out of 18 validation samples on the type of oil or fat present. The concentrations estimated for adulterants showed good agreement with the reference values, with mean errors of prediction (RMSEP) ranging between 0.10 and 0.22% (v/v). The PLS method was efficient in the quantification of mixtures of up to three types of oils and fats, with RMSEP being obtained between 0.08 and 0.27% (v/v), mean precision between 0.07 and 0.32% (v/v) and minimum detectable concentration between 0.23 and 0.81% (v/v) depending on the type of oil or fat in the mixture determined. [Copyright &y& Elsevier]

Abstract: Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was used for the characterization of aromatic compounds present in extra heavy gas oil (EHGO) from Brazil. Individual identification of EHGO compounds was successfully achieved in addition to group-type separation on the chromatographic plane. Many aromatic hydrocarbons, especially polycyclic aromatic hydrocarbons and sulfur compounds, were detected and identified, such as chrysenes, phenanthrenes, perylenes, benzonaphthothiophenes and alkylbenzonaphthothiophenes. In addition, triaromatic steroids, methyl-triaromatic steroids, tetrahydrochrysenes and tetraromatic pentacyclic compounds were present in the EHGO aromatic fractions. Considering the roof-tile effect observed for many of these compound classes and the high number of individual compounds identified, GC×GC-TOFMS is an excellent technique to characterize the molecular composition of the aromatic fraction from EHGO samples. Moreover, data processing allowed the quantification of aromatic compounds, in class and individually, using external standards. EHGO data were obtained in μgg−1, e.g., benzo[a]pyrene were in the range 351 to 1164μgg−1. Thus, GC×GC-TOFMS was successfully applied in EHGO quantitative analysis. [Copyright &y& Elsevier]

The joint analysis of qualitative and quantitative variables has been considered a useful tool to estimate the genetic divergence among accessions of a gene bank. The purpose of this research was: (i) to characterize a collection of cherry tomatoes, using quantitative and qualitative descriptors, and (ii) to use Gower's algorithm to quantify genetic divergence among genotypes, employing a joint descriptors analysis. Forty accessions of organically grown cherry tomato were studied in Seropedica, Rio de Janeiro, Brazil. Four qualitative fruit descriptors and nine qualitative descriptors were used. Data were analyzed using Gower's algorithm. There was variability for color, shape and number of locules per fruit. The red color was observed in fruits of 25 accessions. Fruit with different colors such as yellow, orange and brown were also observed. Regarding locule number, the presence of fruit with two, three, four and even with seven locules was detected. The UPGMA method resulted in the highest value for cophenetic correlation (0.80) and seven clusters were formed. The formed clusters made it possible to distinguish fruit classified as cherry tomato from other type grouped in different clusters, because the fruits this category were larger than cherry type considering the equatorial diameter of the fruit. [ABSTRACT FROM AUTHOR]

The article presents a study that conducts a quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) in the soil of a burned area for agricultural purposes in Brazil. The persistence of individual PAHs varied from 100% to 18.2% with a mean of 57.7%. Except for acenaphthene and naphthalene, PAHs of highest molecular weights showed the largest persistences in soil. This fact may be related to their low water solubilities and to their low vapor pressures. The results suggest also that agricultural practice of vegetation burning may represent a risk for environmental contamination and human exposure since PAHs may be dispersed in the atmosphere over large areas and they may be carried into water bodies contaminating biota and sediments.

Copyright of Revista de Economia e Administração is the property of INSPER Instituto de Ensino e Pesquisa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)