O objetivo deste trabalho foi desenvolver uma metodologia quimiométrica para descrever o perfil químico de amostras de cocaína apreendidas no estado de Minas Gerais (Brasil). A identificação de adulterantes e a quantificação do teor de cocaína foram feitas por cromatografia gasosa acoplada à espectrometria de massa (GC-MS). Espectros de 91 amostras foram obtidos por espectroscopia no infravermelho usando refletância total atenuada (ATR-FTIR), e utilizados na construção de um modelo de análise de componentes principais (PCA). A primeira componente principal (PC1) discriminou as amostras de maior pureza das mais diluídas/adulteradas, nas quais foram identificadas lidocaína, cafeína e benzocaína. PC2 discriminou a forma química da cocaína, cloridrato ou base. Além disso, dois modelos supervisionados discriminantes (mínimos quadrados parciais para análise discriminante, PLS-DA) foram desenvolvidos para classificar as amostras em função de sua diluição (abaixo e acima de 15% m/m) e de sua forma química, apresentando taxas de acerto que variaram entre 83 e 97%. Os modelos de classificação constituem uma ferramenta simples, rápida e não destrutiva, de grande valor para peritos forenses e investigadores criminais. The aim of this article was to develop a chemometric methodology for determining the chemical profile of cocaine samples seized in Minas Gerais State, Brazil. The adulterant detection and the cocaine determination were performed by gas chromatography-mass spectrometry (GC-MS). Spectra of 91 samples were obtained by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and used to build an exploratory principal component analysis (PCA) model. The first principal component (PC1) discriminated samples of more purity from the more diluted/adulterated ones, which were characterized by the presence of lidocaine, caffeine and benzocaine. PC2 discriminated the two chemical forms of cocaine, hydrochloride and base. In addition, two supervised discriminant partial least-squares models (partial least-squares discriminant analysis, PLS-DA) were developed for classifying the samples according to dilution (above and below 15% m/m) and chemical form, with a rate of success that varied between 83 and 97%. The classification models constitute a simple, rapid and non-destructive tool, of great value for both forensic experts and criminal investigators.

O objetivo deste trabalho foi desenvolver uma metodologia quimiométrica para descrever o perfil químico de amostras de cocaína apreendidas no estado de Minas Gerais (Brasil). A identificação de adulterantes e a quantificação do teor de cocaína foram feitas por cromatografia gasosa acoplada à espectrometria de massa (GC-MS). Espectros de 91 amostras foram obtidos por espectroscopia no infravermelho usando refletância total atenuada (ATR-FTIR), e utilizados na construção de um modelo de análise de componentes principais (PCA). A primeira componente principal (PC1) discriminou as amostras de maior pureza das mais diluídas/adulteradas, nas quais foram identificadas lidocaína, cafeína e benzocaína. PC2 discriminou a forma química da cocaína, cloridrato ou base. Além disso, dois modelos supervisionados discriminantes (mínimos quadrados parciais para análise discriminante, PLS-DA) foram desenvolvidos para classificar as amostras em função de sua diluição (abaixo e acima de 15% m/m) e de sua forma química, apresentando taxas de acerto que variaram entre 83 e 97%. Os modelos de classificação constituem uma ferramenta simples, rápida e não destrutiva, de grande valor para peritos forenses e investigadores criminais.The aim of this article was to develop a chemometric methodology for determining the chemical profile of cocaine samples seized in Minas Gerais State, Brazil. The adulterant detection and the cocaine determination were performed by gas chromatography-mass spectrometry (GC-MS). Spectra of 91 samples were obtained by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and used to build an exploratory principal component analysis (PCA) model. The first principal component (PC1) discriminated samples of more purity from the more diluted/adulterated ones, which were characterized by the presence of lidocaine, caffeine and benzocaine. PC2 discriminated the two chemical forms of cocaine, hydrochloride and base. In addition, two supervised discriminant partial least-squares models (partial least-squares discriminant analysis, PLS-DA) were developed for classifying the samples according to dilution (above and below 15% m/m) and chemical form, with a rate of success that varied between 83 and 97%. The classification models constitute a simple, rapid and non-destructive tool, of great value for both forensic experts and criminal investigators. Keywords: illicit drugs, MID infrared, principal component analysis, cocaine, chemometrics IntroductionCocaine is an alkaloid extracted from plants of the genera Erythroxylum (E. novagranatense and E. coca). United Nations Office on Drugs and Crime (UNODC) considers cocaine, after heroin, the second most problematic drug worldwide in terms of negative health consequences and probably the most problematic drug in terms of trafficking-related violence. Estimates suggest that 440 t of pure cocaine were consumed in the world in 2009, which would be in line with a total production estimate of 1,111 t, wholesale purity-adjusted seizures Analysis of Seized Cocain...

A ocorrência de ftalato de di(2-etilhexila) (DEHP) e bisfenol A (BPA) em águas residuais da estação de tratamento da Universidade de Caxias do sul (ETE-UCS) foi investigada neste trabalho. Durante cinco meses, cinco amostras dos pontos de entrada e saída da ETE-UCS foram coletadas e submetidas à extração líquido-líquido (LLE). Os extratos orgânicos foram analisados por cromatografia a gás com detecção por ionização em chama (GC/FID). As eficiências de remoção da ETE-UCS foram de 37,79 e 19,90% para BPA e DEHP, respectivamente. As concentrações médias no ponto de saída foram 52,52 e 20,00 mg L -1 para BPA e DEHP, respectivamente. As concentrações altas dos analitos, no ponto de saída da ETE podem estar relacionadas com a remoção baixa dos sólidos suspensos das amostras brutas. Para confirmar esta hipótese, outras cinco amostras dos pontos de entrada e saída da ETE-UCS também foram submetidas à LLE, com e sem o procedimento de pré-filtração. A remoção de DEHP foi de 74,44% sendo a concentração média no ponto de saída de 6,01 mg L -1 . Para as amostras não pré-filtradas a remoção de DEHP foi de 40,96% sendo a concentração média no ponto de saída de 17,04 mg L -1 .This study investigated the occurrence of di(2-ethylhexyl)phthalate (DEHP) and bisphenol A (BPA) in the wastewater treatment plant of the University of Caxias do Sul (WWTP-UCS). During five months, five wastewater samples from the inflow and outflow points were collected and submitted to liquid-liquid extraction (LLE). The organic extracts were analyzed by gas chromatography with flame ionization detection (GC/FID). The removals grades were 37.79 and 19.90% for BPA and DEHP, respectively. The average concentrations at the outflow points were 52.52, and 20.00 mg L -1 , for BPA and DEHP, respectively. These high target compound contents at the exit point may be due to the low removal of suspended solids from the raw samples (only 42.72% removal). To confirm this hypothesis, other five samples also from the inflow and out flow points were submitted to LLE extraction with and without the prefiltration step. The DEHP removal in the filtered samples was 74.44% and the median DEHP concentration at the outflow point was 6.01 mg L -1 . For the unfiltered samples, the DEHP removal was 40.96% and the median DEHP concentration at the outflow point was 17.04 mg L -1 .Keywords: liquid residues, gas chromatography, bisphenol A, di(2-ethylhexyl)phthalate IntroductionPlasticizers are organic compounds added to polymers to facilitate processing and increase flexibility and toughness of the final product by internal modification of the polymer molecule. Phthalates, including DEHP, are a family of plasticizers and dominate polymer production.DEHP can interfere in the functioning of the endocrine system and in the mechanism of hormone action. Endocrine deregulators or endocrine disruptors may cause reproductive anomalies (morphological and functional gonadal dysfunction, infertility and decreased libido) and congenital malformations. [1][2][3] reported associations between dus...

The purpose of this work was the quantitative analysis of bisphenol A (BPA), in soil of two sanitary landfills in Caxias do Sul and Farroupilha, RS-Brazil. The samples were collected from closed cells and extracted by Soxhlet. The organic extracts were analyzed by Gas Chromatography with Flame Ionization Detector (GC/FID) and BPA was quantified by the internal normalization method. Standard bisphenol A (Sigma-Aldrich, 99.00%) was used for qualitative and quantitative analysis. The average concentration of BPA was of 21.30 (0.61) µg g -1 of soil. The BPA concentration found in this work is much higher than the others reported in the literature. This result is worrying because there is a suspicion that bisphenol A disrupts the endocrine system.

O principal objetivo deste trabalho foi o estudo do perfil de evaporação de BTEX (benzeno, tolueno, etilbenzeno e xilenos) em amostras de gasolina pura e mistura de gasolina-etanol. Os vapores de duas colunas lacradas contendo areia de fundo de rio e água destilada foram monitorados por 18 dias por SPME (micro extração em fase sólida). BTEX que permaneceram na fase aquosa e na areia foram extraídos por SPE (extração em fase sólida) e Soxhlet, respectivamente. A análise instrumental foi realizada por cromatografia a gás com detector por ionização de chama (GC/FID). Tolueno e etilbenzeno apresentaram as maiores volatilizações na coluna contendo a mistura gasolina-etanol. Esta distribuição pode ser devida à ocorrência de forças atrativas envolvendo moléculas de etanol e de BTEX. O benzeno foi o composto com maior retenção na fase areia da coluna contendo a mistura gasolina-etanol. The main objective of the present study was to assess the evaporation profile of BTEX (benzene, toluene, ethylbenzene and xylenes) in neat gasoline and gasoline-ethanol blend fuels. The vapors from two sealed columns containing river sand and distilled water were monitored during 18 days by SPME (solid-phase microextraction). BTEX that remained in the water and sand phases were extracted by SPE (solid-phase extraction) and Soxhlet, respectively. Instrumental analysis was performed by gas chromatography using a flame ionization detector (GC/FID). Toluene and ethylbenzene showed the highest volatilizations in the gasoline-ethanol column and the occurrence of attractive intermolecular forces among ethanol and BTEX molecules can be responsible for this distribution. Benzene showed the lowest reduction of concentration in the sand compartment in the gasoline-ethanol column.

The effects of di-n-butylphthalate (DnBP) were investigated with respect to bioaccumulation and whether these effects occurred over a second generation in the fall armyworm Spodoptera frugiperda (J.E. Smith, 1797). The concentrations of DnBP in males and females of the second generation were higher than those in first one. However, frequency of mortality of exposed individuals in the second generation was approximately 57% less but the reduction in size and weight was more pronounced than in the first generation.

The present study has investigated the influence of the filtration step of the liquid-liquid extraction (LLE) on the quantitative analysis of di-n-butyl phthalate (DnBP) in the wastewater treatment system of the University of Caxias do Sul (WWTS-UCS). During five months, five wastewater samples from the inflow and outflow points were collected and submitted to LLE with and without the filtration step. The organic extracts were analyzed by Gas Chromatography with Flame Ionization Detection (GC/FID). The DnBP removal in the filtered samples was 36%, and the median DnBP concentration at the outflow point was 17.45 μg/mL. For the unfiltered samples, the DnBP removal was 39%, and the median DnBP concentration at the outflow point was 21.45 μg/mL. According to these results, an important fraction of the contaminant is retained in the LLE filtration step leading to considerable errors in the quantification of the target compounds.

In this work experiments were performed with vapor collection in columns to assess the evaporation profile of benzene from gasoline-ethanol blend fuels. The vapors from two columns simulating gasoline-contaminated soils (with and without ethanol) were monitored for 77 d. The instrumental analysis was performed by Gas Chromatography (GC) with a Flame Ionization Detector (FID). Compound identification was based on the GC retention times of standard BTX (benzene, toluene and xylenes). The concentration of benzene in the vapor phase decreased by 89.09%, considering the entire experimental period, while the toluene and xylene concentrations were increased by 239.34 and 251.78%, respectively. These results suggest that the benzene evaporation behavior was affected by the interactions among ethanol and other aromatic compounds. These results are particularly important, since ethanol is an alternative to gasoline blends. Furthermore, benzene (a well known carcinogen) was retained in the liquid phase and, in this way, can reach the underground water sources. These findings can point out necessary changes in traditional risk models for soil spills that are based on compound concentrations in the environment.