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Foram analisados os ésteres metílicos de ácidos graxos (FAMEs) em amostras comerciais de leite empregando cromatografia gasosa acoplada ao detector por ionização em chama. Os ácidos graxos saturados (SFA) foram os mais abundantes. Os principais SFA encontrados foram o ácido palmítico (16:0), o ácido esteárico (18:0) e o ácido mirístico (14:0). Foram obtidas diferenças significativas (P < 0,500) entre as quantidades de ácido palmítico (276 ± 17 mg g -1 e 248 ± 20 mg g -1 ) e ácido mirístico (95 ± 5 mg g -1 e 85 ± 7 mg g -1 ) nas amostras analisadas. Entretanto, não foi observada uma diferença significativa para o ácido esteárico (113 ± 6 mg g -1 e 114 ± 11 mg g -1 ). O isômero conjugado do ácido linoleico (CLA) 18:2c9t11 foi detectado nas amostras e quantificado. Para este ácido, as diferenças encontradas nas amostras analisadas não foram significativas (10,4 ± 0,7 mg g -1 e 9,9 ± 0,6 mg g -1 ). A análise de uma amostra do material de referência certificado de leite (RM-8435 NIST) mostrou uma boa recuperação (> 80%) indicando que o método pode ser aplicado para determinar eficientemente ácidos graxos em amostras de leite e em produtos lácteos.Fatty acid methyl esters (FAMEs) in commercial milk samples were analyzed by gas chromatography coupled with flame ionization detection. The saturated fatty acids (SFA) were the most abundant. The major SFA were palmitic acid (16:0), estearic acid (18:0), and myristic acid (14:0). Significant differences (P < 0.500) were found between the amounts of palmitic acid (276 ± 17 mg g -1 and 248 ± 20 mg g -1 ) and myristic acid (95 ± 5 mg g -1 and 85 ± 7 mg g -1 ) in samples. However, no difference was observed for estearic acid (113 ± 6 mg g -1 and 114 ± 11 mg g -1 ). The conjugated linoleic acid (CLA) isomer 18:2c9t11 was detected in the samples and quantified. However, the differences found between the samples analyzed were not significant (10.4 ± 0.7 mg g -1 and 9.9 ± 0.6 mg g -1 ). The analysis of a certified reference powder milk sample (RM-8435 NIST) gave good recoveries (> 80%), indicating that the method can efficiently determine fatty acids in milk and dairy products.

Pesticide pollution in water has been well described; however, little is known on pesticide accumulation by aquatic organisms, and to date, most studies in this line have been focused on persistent organochlorine pesticides. For this reason, a method based on QuEChERS extraction and subsequent liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed and validated for the determination of 52 medium to highly polar pesticides in fresh fish muscle. Target pesticides were selected on the basis of use and occurrence in surface waters. Quantification is carried out following an isotope dilution approach. The method developed is satisfactory in terms of accuracy (relative recovery between 71-120%), precision (relative standard deviation below 20.6%) and sensitivity (limits of determination in the pg/g or low ng/g f.w. range for most compounds). The application of the validated methodology to fish specimens collected from the Adige River (Italy) revealed the presence of trace levels of diazinon, dichlorvos and diuron, and measurable levels of metolachlor, quinoxyfen, irgarol, terbutryn, and acetamiprid, but in all cases at concentrations below the default maximum residue level of 10 ng/g established for pesticides not specifically regulated in fish. Metolachlor and quinoxyfen were both the most ubiquitous and abundant pesticides, in agreement with their high potential of bioaccumulation. Both are toxic to aquatic organisms, and therefore, their potential effects on aquatic ecosystems should be further explored.

Lipid supplements (oilseeds vegetables) are included in ruminant diet to increase its energy density and improve fatty acid composition of milk and consequently of fresh cheese. Milk and cheeses were evaluated from crossbred Holstein × Zebu, fed diets enriched with 0%, 25%, 50%, and 75% inclusion levels of palm kernel cake in concentrated supplement, which were supplied daily (3.0 kg). Milk and fresh cheese (p = 0.001) fatty acids C12:0 exhibited quadratic negative values. Milk fatty acids C13:0, C20:0, C18:2t10c12, and C20:2n-6 presented positive quadratic values. The milk C18:2n-6 decreased linearly and in fresh cheese exhibited an increasing linear effect (p = 0.016). However, the fatty acids grouped in milk fat were not affected. The medium-chain fatty acids varied negatively and quadratically (p = 0.045). There was no effect on milk and fresh cheese chemical composition (p > 0.05). The milk fat was increased (p = 0.0065) quadratically (minimum point of 24.7%). Thus, the addition of palm kernel cake to cow diets negatively altered the fatty acid profile, it raises the percentage OPEN ACCESSMolecules 2015, 20 15435 of lauric (C12) and tridecanoic (C13) acids fat which is not beneficial to human health from a nutraceutical perspective, although it did not influence the atherogenicity index.

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Chitin, extracted from silkworm chrysalides, was employed for the production of a high-purity and porous chitosan, as observed by scanning electron microscopy. Chitin and the chitosan produced from it were also analysed using 13 C NMR spectroscopy to show the efficiency of deacetylation. The extracted chitin was investigated as an adsorbent material for aluminium removal from textile wastewater, by the column chromatographic method. After the treatment, the residual aluminium was lower than the limitation criterion of 0.2 mg L −1 . The isotherms of adsorption on chitin and chitosan surfaces were investigated and the best fits were observed using the Freundlich isotherm. At pH 5.0, the maximum adsorption capacity was 21.3 mg of aluminium per gram of chitosan over 70 h of experiments.