J. Simal Gándara

Multiresidue method for fourteen fungicides in white grapes by liquid–liquid and solid-phase extraction followed by liquid chromatography–diode array detection

A quantitative, selective and sensitive HPLC method for the analysis of 14 fungicides in white grapes for vinification is described. The proposed method is based on liquid-liquid extraction (LLE) and solid-phase extraction (SPE) followed by liquid chromatography and diode array detection (HPLC-DAD). Dichloromethane-acetone (75:25, v/v) was the most appropriate solvent mix for extracting fungicides in white grapes. Silica cartridges resulted the most appropriate for extract purification purposes. Quality parameters of the proposed multiresidue method presented good recovery (ca. 85% for almost all target compounds) and precision (between 1.5 and 16%), and detection limits lower than maxima residual limits set by the 76/895/ECC and 90/642/ECC Directive. Five different white grapes for vinification produced in Rias Baixas area in Galicia (NW Spain) were analyzed in order to assess the performance of the method with real samples and to determine whether the concentration of the pesticides used exceed their maxima residue levels (MRLs). Results showed that grape concentrations for those identified fungicides were lower than those established by European legislation.

Solid-phase microextraction-gas chromatographic-mass spectrometric method for the determination of the fungicides cyprodinil and fludioxonil in white wines.

Abstract A solid-phase microextraction (SPME) followed by a gas chromatographic–mass spectrometric (GC–MS) determination has been developed and validated for the determination of cyprodinil and fludioxonil in white wine samples. Extraction parameters such as the selection of SPME coating, the effect of the temperature, the effect of the headspace volume and the salt addition were studied and optimized, together with GC–MS analytical conditions. The divinylbenzene–Carboxen–polydimethylsiloxane (DVB–CAR–PDMS) fiber was the most appropriate for the determination of the two pesticides in wine. The quality parameters of the proposed method demonstrated a good precision (RSD about 5%), with detection limits of 0.1 and 0.2 μg/l for cyprodinil and fludioxonil, respectively. Fifteen commercial white wine samples produced in Rias Baixas area in Galicia (N.W. Spain) were analyzed with the SPME–GC–MS procedure. Some of the commercial wines (75%) presented the two pesticides in concentrations ranging from 0.9 to 28.6 μg/l. In conclusion, SPME–GC–MS has a great potential for fungicide determination in wines.

Kinetics of the hydrolysis of bisphenol A diglycidyl ether (BADGE) in water-based food simulants

SummaryThe first-order degradation kinetics of bisphenol A diglycidyl ether (BADGE; CAS No. 1675-54-3) has been studied in three water-based food simulants (3% (W/V) acetic acid, distilled water and 15% (V/V) ethanol) at various temperatures. BADGE and its first and second hydrolysis products were determined by reversed-phase high-performance liquid chromatography with fluorescence detection. Nonlinear regression was used to fit the experimental data at 40, 50 and 60°C with the proposed kinetic equations; Arrhenius equation was then fitted to the rate constants obtained and the kinetic models were tested by comparing experimental data obtained at 70°C with the kinetic curves calculated using the rate constants predicted for this temperature. The half-life of BADGE was longest in ethanol and shortest in acetic acid. The rings opening in acetic acid appears to happen by means of active hydrogens whereas in the other simulants it is mainly influenced by the formation of acid/base adducts. The results imply that resins which comply with existing legislation on the migration of unreacted monomer may still contaminate foodstuffs.

Overall migration and specific migration of bisphenol A diglycidyl ether monomer and m‐xylylenediamine hardener from an optimized epoxy‐amine formulation into water‐based food simulants

The overall and specific migrations of BADGE n = 0 monomer and m‐XDA hardener from a BEPOX LAB 889 (Gairesa internal code), epoxy system cured at room temperature, into three water‐based food simulants are studied. Hydrolysis of BADGE n = 0 was observed in all of these simulants, giving more polar products. We thus propose changing the EEC Directives, which at present only legislate for levels of BADGE n = 0 monomer in the simulants, to include the hydrolysis products of BADGE monomers. Another alternative would be to express all the migration levels due to BADGE and its derived products in terms of BADGE itself.

Identification of RP-HPLC peaks of bisphenol F and of bisphenol F diglycidyl ether and its hydrolysis products by thermospray mass spectrometry and gas chromatography/mass spectrometry

The need to determine the migration of toxic unreacted compounds in bisphenol diglycidyl ether epoxy resins prompted us to investigate the HPLC properties of bisphenol F diglycidyl ether and its hydrolysis products in the water-based food simulants 3% (w/v) acetic acid, distilled water and 15% (v/v) ethanol. Peaks were identified by reversed-phase HPLC thermospray mass spectrometry and gas chromatography/mass spectrometry.

Quantitative analysis of colistin and tiamulin in liquid and solid medicated premixes by HPLC with diode-array detection

SummaryColistin (COL) and tiamulin (TML) are antibiotics used in veterinary practice. Diseases in animals are usually treated by adding the drug (liquid and/or solid medicated premix) to animal feed. Two simple, inexpensive, and rapid methods have been developed for quantification of COL and TML in liquid and solid medicated premixes by HPLC with diode-array detection, on the basis of scanning in the UV range 200–380 nm. The wavelengths 206 and 208 nm were used for quantification of COL and TML, respectively. The total elution time was less than 15 min. When the applicability of the optimized method was tested by analysis of commercial feed premixes there was no interference from the matrix.

Infrared spectrophotometric determination of citral corrected for limonene interference in lemon and orange essential oils

An infrared spectrophotometric method is described to correct for interference by limonene in the determination of citral in orange and lemon essential oils by subtracting the limonene spectrum from the essential oil spectrum. The first derivative trough-to-peak distance between 1684 cm−1 and 1677 cm−1 was most reliable in determining citral, parameters of the zero order absorption spectrum (net absorbance and peak area) performed poorly in comparison.

Determination of total oil in petroleum tanker ballast water by zeroth-, first- and second-derivative infrared spectrophotometry and least-squares curve fitting

Abstract A rapid method for the determination of total hydrocarbons in random samples of oil tanker ballast water is described. A 1-l sample is treated with CCl 4 after acidification with HCl. The organic extract is analysed by measuring features in the zeroth-, first- and second-derivative infrared spectra using the Perkin-Elmer SNGLE program and by means of least-squares curve-fitting algorithms of the zeroth- or first-derivative IR spectra using the Perkin-Elmer QUEST program.

EL USO DE LOS ANTIBIÓTICOS EN LA ALIMENTACIÓN ANIMAL: PERSPECTIVA ACTUAL THE USE OF ANTIBIOTICS IN ANIMAL FEEDS: AN ACTUAL PERSPECTIVE O USO DOS ANTIBIÓTICOS NA ALIMENTACIÓN ANIMAL: PERSPECTIVA ACTUAL

Abstract The main objective in animal farms is to achieve a high birth rate and to maximise productive performance in terms of average daily gains and feed efficiency at less cost. Another objective is to decrease the incidence and the persistence of infections. The use of antibiotics has a double function. As a first function, antibiotics are used with therapeutic purposes, being the medicated feeds the most common mode of administration of the drug. As a second function, antibiotics can be used as feed additives in order to operate as growth promoters. However, there is a growing public concern on the negative effects of the use of antibiotics, especially because of the possibility of resistance development by gut microorganism that can be transferred to humans. Resumen Conseguir una tasa de natalidad elevada así como una mayor rapidez en la capacidad de engorde y en el crecimiento de la producción animal son actualmente los principales objetivos en las grandes explotaciones. Al mismo tiempo, la mezcla de animales destinados al consumo con diferentes procedencias en lugares reducidos de estas explotaciones, favorece el contacto y la persistencia con agentes parasitarios e infecciosos. Ante estas dos situaciones, el uso de los antibióticos presenta un doble papel. En primer lugar, éstos pueden utilizarse con fines terapéuticos siendo los piensos medicamentosos una de las vías más usadas para administrar el fármaco. En segundo lugar, pueden emplearse como promotores de crecimiento animal f avoreciendo el control de la flora bacteriana, lo que conlleva un mayor aprovechamiento de los nutrientes y un aumento considerable de peso. Investigaciones realizadas en los últimos años demuestran la posible relación entre el consumo de antibióticos por animales y la aparición de bacterias resistentes, tanto en estos animales como en los consumidores de alimentos procedentes de los primeros. Palabras clave: antibióticos, piensos medicamentosos, premezclas medicamentosas, promotores de crecimiento. Resumo Conseguir unha tasa de natalidade elevada así como unha maior rapidez na capacidade de engorde e no crecemento da producción animal son actualmente os principais obxetivos nas grandes explotacións. Ó mesmo tempo, a mistura de animais destinados ó consumo con diferentes procedencias en lugares reducidos destas explotacións, favorece o contacto e a persistencia con axentes parasitarios e infecciosos. Ante estas duas situacións, o uso dos antibióticos presenta un doble papel. En primeiro lugar, éstes poden utilizarse con fins terapéuticos sendo os pensos medicamentosos unha das vías máis usadas para administra-lo fármaco. En segundo lugar, pódense emplear como promotores do crecemento animal favorecendo o control da flora bacteriana do tubo dixestivo, o que conleva un maior aproveitamento dos nutrintes e un aumento considerable do peso. Pesquisas realizadas nos últimos anos demostran a posible relación entre o consumo de antibióticos por animais e a aparición de bacterias resistentes, tanto nestes animais como nos consumidores de alimentos procedentes dos primeiros. Palabras chave: antibióticos, pensos medicamentosos, premisturas medicamentosas, promotores do crecemento.

BEBIDAS ENRIQUECIDAS CON VITAMINAS ANTIOXIDANTES: ASPECTOSLEGALESY ESTUDIO DE SU ETIQUETADO NUTRICIONAL ENRICHED BEVERAGE WITH ANTIOXIDANT VITAMINS: LEGAL ASPECTS AND A STUDY OF THE NUTRITIONAL LABELING BEBIDAS ENRIQUECIDAS CON VITAMINAS ANTIOXIDANTES: ASPECTOS LEGAIS Y ESTUDIO DO SEU ETIQUETADO NUTRICIONAL

Abstract Due to the benefits of antioxidant vitamins A, E and C, in the protection of the organism against free radicals, they are being increasingly used by the food industry to enrich foodstuffs, including a large variety of beverages. On the contrary than in USA or Japan, in Europe there are no specific regulations to control these products. This legal gap is contributing to the confusion of the consumers, producing problematic situations in some sectors of the population, such as in the case of pregnant women. According to nutritional labeling, this type of enriched products must reflect the nutritional properties. To verify whether these products fulfil the regulation in this study we checked labels in 16 samples, observing irregularities in the about 81% of the products. These irregularities are mainly: incorrect expressions of vitamin contents, omission of vitamin A proportions regarding RDAs, and deficiencies in the lowest level of vitamin C for enrichment.