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Polylactic acid (PLA) is a biopolymer commonly used in food packaging due to its good characteristics, similar to PET. To evaluate the safety of this material, the analysis of the non-intentionally added substances (NIAS) is required. Oligomers are NIAS and their behavior needs a deep study, especially if they migrate to the food. In this work, the analysis of the polymer and the migration to food simulants was carried out. A total dissolution/precipitation procedure was applied to PLA pellets and films, using dichloromethane and ethanol as solvent and antisolvent system respectively. The migration tests were carried out in three liquid simulants to mimic any kind of food. Since oligomers are not present in the positive list of the Directive 10/2011/EC, their concentration must be below the 0.01 mg/kg of food. UPLC-QTOF-MS, with and without ion mobility (IM), was used for the analysis. Thirty-nine different PLA oligomers made of repeated monomer units of [LA] (C3H4O2) and with different structures were identified. They corresponded to cyclic oligomers with [LA]n structure and two groups of linear oligomers, one with an hydroxyl group, OH–[LA]n–H, and the other one with an ethoxy group, CH3–CH2–O–[LA]n–H. Cyclic oligomers only appeared in the material and were not present in migration solutions. Linear oligomers HO–[LA]n–H were already present in the pellets/film and they migrated in a higher extension to aqueous food simulants (EtOH 10% and AcH 3%). However, linear oligomers CH3–CH2–O–[LA]n–H were not present initially in the pellets/film, but were detected in migration to simulants with ethanol content, EtOH 95% and EtOH 10%. Furthermore, 5 cyclic polyester oligomers were identified in migration. Ethanol 95% and ethanol 10% migration solutions were also analyzed by scanning electron microscopy (SEM), and the presence of microstructures that could be attributed to the oligomers migration was found. They could be seen as microplastics.

The aim of this work was to select and identify the best markers of aromatic hydrocarbon mineral oil (MOAH) in food packaging. For this purpose, a series of mineral oils was initially analysed. Polycyclic Aromatic Hydrocarbons (PAHs) and the alkylated isomers of Methylnaphthalene (MNS), Diisopropylnaphtalene (DIPNs), Dibenzothiophenes (DBTS), Methyldibenzothiophene (MDBTs), Dimethyldibenzothiophenes (DMDBTs) and Benzonaphthiophenes (BNTS) were then explored. Their presence was confirmed by direct analysis of several mineral oils by Atmospheric Solids Analysis Probe Quadrupole-Time of Flight Mass Spectrometry (ASAP-QTOF-MS). Atmospheric Pressure Gas Chromatography Quadrupole-Time of Flight Mass Spectrometry (APGC-QTOF-MS) was used to confirm the markers in different samples of oils, recycled PET (rPET), recycled cardboard and packaging of couscous and semolina to confirm the contamination. 27 markers were found in the mineral oil samples, 22 of them in rPET, 8 in recycled board and no MOAH were found in packaging of couscous and semolina.

We study properties of the critical points of orthogonal polynomials with respect to a measure on the unit circle (OPUC). The main result states that, under some conditions, the asymptotic distribution of the critical points of OPUC coincides with the asymptotic distribution of its zeros and each NevaiTotik point attracts the same number of critical points as zeros of the OPUC. Analogous results are also presented for paraorthogonal polynomials and for orthogonal polynomials with respect to a regular measure supported on a continuum set. © 2017 Elsevier Inc.

La presente investigación tiene como objetivo evaluar la viabilidad económica, financiera y técnica en la implementación de una plataforma de comunicación en tiempo real entre colegio, padres de familia y alumnos. Está dirigido a los colegios particulares de primaria y secundaria de los distritos de Lima Metropolitana, El factor de diferenciación para el Plan de Negocio es buscar satisfacer a las instituciones educativas que no pueden acceder a una plataforma integral de gestión educativa y que buscan una alternativa que les permita acceder a herramientas de comunicación en línea, haciendo uso de la tecnología móvil entre los miembros de la comunidad educativa. Asimismo, las instituciones educativas que obtén por Eduline School (servicio específico de aplicación móvil que gestiona específicamente la comunicación) permitirán que el factor de la Tecnología se incorpore en sus escuelas logrando de esta manera que la imagen del colegio apunte a la modernidad y a la conectividad. Finalmente, se concluye que el Plan de Negocios de la aplicación móvil para la comunidad educativa es viable y rentable, lo cual está sustentado con un mercado interesado en entablar un vínculo más cercano entre la familia y colegio que genere un incremento en el sentido de pertenencia y confianza entre estos dos agentes esenciales. Trabajo de Investigación

A novel and fast salting out liquid-liquid extraction method was developed for simultaneous determination of food additives with different polarities in juices. Chromatographic separation was achieved in less than 6 min using Acquity UPLC BEH C 18 (100 mm × 2.1 mm d.i. × 1.7 µm) column with ammonium acetate with 0.01% of trifluoroacetic acid as eluent A and acetonitrile as eluent B at a flow rate of 0.2 mL min−1. The main factors affecting the extraction efficiency were optimized. The method was validated applying accuracy profile based on total error. The extraction recoveries ranged from 84.97 to 122%. Relative standard deviation ranged from 1.24 to 7.99% for intraday assay and from 1.69 to 9.16% for intermediate precision. The limits of detection for five food additives were from 0.3 to 1.42 µg mL−1. The method was successfully applied to 47 samples of juices from nine brands.

Zoel García de Galdeano y Yanguas (Pamplona, 1846 - Zaragoza, 1924), catedrático de Geometría Analítica (1889- 1896) y Cálculo Infinitesimal (1896-1918) de la Facultad de Ciencias de la Universidad de Zaragoza fue, junto a José Echegaray y Eizaguirre (1832-1916) y Eduardo Torroja y Caballé (1847-1918), uno de los tres artífices de la modernización matemática española en la Restauración. Las realizaciones que le hicieron merecedor de este reconocimiento por parte de la comunidad matemática se estructuran en cuatro ámbitos de actuación. García de Galdeano, que fue maestro y catedrático de instituto antes que profesor de universidad, mostró desde la década de los setenta su compromiso con la renovación de la enseñanza de las matemáticas en España, tanto en su vertiente didáctica como curricular: de los dos centenares de títulos que publicó sobre temas matemáticos, más de la cuarta parte están dedicados a temas de enseñanza, didáctica y pedagogía. Prueba fehaciente de esta vocación fue el legado a la Universidad de Zaragoza de su colección de modelos matemáticos, originalmente diseñados y construidos bajo la dirección de los matemáticos Alexander von Brill y Felix Klein para facilitar el aprendizaje de la matemática más abstracta. Estos modelos, que forman parte de la exposición permanente de la Facultad de Ciencias, se muestran en la Sala África Ibarra del Paraninfo del 30 de enero al 28 de febrero de 2017. La cuestión de fondo no era otra que atajar el problema del retraso matemático español, una tarea que Galdeano se propuso desde la década de los ochenta. Su Crítica y síntesis de álgebra (1888) muestra la profundidad, actualidad y proyección de futuro de sus conocimientos algebraicos, la profusión de su erudición bibliográfica y, lo que es más importante, la habilidad para identificar las contribuciones más significativas. Es además, el primer trabajo en el que García de Galdeano incluye numerosas referencias bibliográficas —proporcionando en la medida de lo posible referencias a traducciones francesas de obras alemanas para facilitar el estudio y la investigación.

We establish the Mehler–Heine type formulae for orthonormal polynomials with respect to generalized Freud weights. Using this type of asymptotics, we can give estimates of the value at the origin of these polynomials and of all their derivatives as well as the asymptotic behavior of the corresponding zeros.

Within the family of polycyclic aromatic hydrocarbons (PAHs), nitrated derivatives are of particular interest in environmental science because they have well-known carcinogenic and mutagenic effects. They are in fact more toxic than their parent PAHs. One valuable diagnosis of atmospheric pollution can be obtained using biomonitors such as mosses. These biomonitors can provide information about air pollution over long periods of time in wilderness areas. Thus, they can serve as monitors of the atmospheric transport of pollutants. In this study, atmospheric pressure gas chromatography coupled to a quadrupole hyphenated to a time of flight mass spectrometer (APGC–MS/Q-TOF) has been examined for the identification of target analytes (15 PAHs and 8 NPAHs) for subsequent use in the analysis of mosses. Working ranges in low μg g −1 concentration levels were obtained with most correlation coefficients higher than 0.999. All LODs were in the 0.007–0.035 μg g −1 range and higher LODs (0.035 μg g −1 ) were obtained for the less volatile PAHs with higher mass and retention times: benzo(g,h,i)perylene, dibenz(a,h)anthracene and indeno(1,2,3-c,d)pyrene. These LODs are of importance for the intended use, biomonitoring, especially taking into account that NPAHs are commonly found at very low concentration levels. Recoveries from mosses ranged from 75 to 98%. Intraday and interday precision ranged from 1.8 to 11.1% RSD and from 2.4 to 16.7% RSD, respectively. Very low concentrations of NPAHs were found in mosses compared to those of PAHs. All these data were used for pattern recognition of the pollutant source. The results are shown and discussed.

Ultra-performance liquid chromatography (UPLC) coupled to mass spectrometry (MS) is a useful tool in the analysis of non-volatile compounds, and the use of a quadrupole-time-of-flight (Q-TOF) mass analyzer allows a high sensitivity and accuracy when acquiring full fragment mode, providing a high assurance of correct identification of unknown compounds. In this work, UPLC-Q-TOF-MS technology has been applied to the analysis of non-volatile migrants from new active packaging materials. The materials tested were based on polypropylene (PP), ethylene-vinyl alcohol copolymer (EVOH), and poly(ethylene terephthalate) (PET). The active packaging materials studied were one PP film containing a natural antioxidant, and two PP/EVOH films, two PET/EVOH films and one coextruded PP/EVOH/PP film containing natural antimicrobials. The chemical structure of several compounds was unequivocally identified. The analysis revealed the migration of some of the active substances used in the manufacture of active packaging, such as caffeine (0.07 ± 0.01 μg/g), carvacrol (0.31 ± 0.03 μg/g) and citral (0.20 ± 0.01 μg/g). Unintentionally added substances were also found, such as citral reaction compounds, or citral impurities present in the raw materials.

This paper deals with Mehler–Heine type asymptotic formulas for the so-called discrete Sobolev orthogonal polynomials whose continuous part is given by Laguerre and generalized Hermite measures. We use a new approach which allows to solve the problem when the discrete part contains an arbitrary (finite) number of mass points.

In most cases, food packaging materials contain inks whose components can migrate to food by diffusion through the material as well as by set-off phenomena. In this work, different mass spectrometry approaches had been used in order to identify and confirm the presence of ink components in ethanol (95%) and Tenax(®) as food simulants. Three different sets of materials, manufactured with different printing technologies and with different structures, were analyzed. Sample analysis by ultra performance liquid chromatography mass spectrometry (UPLC-MS), using a quadrupole-time of flight (Q-TOF) as a mass analyser proved to be an excellent tool for identification purposes while ion mobility mass spectrometry (IM-MS) shown to be very useful for the confirmation of the candidates proposed. The results showed the presence of different non-volatile ink components in migration such as colorants (Solvent Red 49), plasticizers (dimethyl sebacate, tributyl o-acetyl citrate) or surfactants (SchercodineM, triethylene glycol caprilate). An oxidation product of an ink additive (triphenyl phosphine oxide) was also detected. In addition, a surface analysis technique, desorption electrospray mass spectrometry (DESI-MS), was used for analyzing the distribution of some ink components (tributyl o-acetyl citrate Schercodine L, phthalates) in the material. The detection of some of these compounds in the back-printed side confirmed the transference of this compound from the non-food to the food contact side. The results also showed that concentration of ink migrants decreased when an aluminum or polypropylene layer covered the ink. When aluminum was used, concentration of most of ink migrants decreased, and for 5 out of the 9 even disappeared.

A new screening method has been explored for direct analysis of tobacco smoke biomarkers in biological matrices (i.e., saliva and urine). Single run analysis using Atmospheric pressure Solid Analysis Probe (ASAP) and high resolution mass spectrometry with quadrupole and time of flight detector has been applied directly to some biological samples (i.e., urine and saliva), providing a fast, efficient and sensitive method of identification. The method has been applied to saliva and urine samples from heavy tobacco smokers for exposure studies. Nicotine itself, nicotine metabolites (i.e., cotinine, trans-3'-hydroxycotinine, nicotine-N-glucuronide) and other related tobacco smoke toxic compounds (i.e., NNK 4-[methyl(nitroso)amino]-1-(3-pyridinyl)-1-butanone, anatabine) were found in the analyzed samples. The identification of compounds was confirmed by ultrahigh performance liquid chromatography with MS-triple quadrupole detector after sample treatment. Different temporal trends and biomarkers behavior have been found in time series related samples. Both methods are compared for screening of these biological matrices.

A new screening and semi-quantitative approach has been developed for direct analysis of polycyclic aromatic hydrocarbons (PAHs) and their nitro and oxo derivatives in environmental and biological matrices using atmospheric pressure solid analysis probe (ASAP) quadrupole-time of flight mass spectrometry (Q-TOF-MS). The instrumental parameters were optimized for the analysis of all these compounds, without previous sample treatment, in soil, motor oil, atmospheric particles (ashes) and biological samples such as urine and saliva of smokers and non-smokers. Ion source parameters in the MS were found to be the key parameters, with little variation within PAHs families. The optimized corona current was 4 µA, sample cone voltage 80 V for PAHs, nitro-PAHs and oxo-PAHs, while the desolvation temperatures varied from 300°C to 500°C. The analytical method performance was checked using a certified reference material. Two deuterated compounds were used as internal standards for semi-quantitative purposes together with the pure individual standard for each compound and the corresponding calibration plot. The compounds nitro PAH 9-nitroanthracene and oxo-PAH 1,4-naphthalenedione, were found in saliva and urine in a range below 1 µg/g while the range of PAHs in these samples was below 2 µg/g. Environmental samples provided higher concentration of all pollutants than urine and saliva.

High levels of reproductive failure were detected in some Spanish sow farms in the Spring of 2010. Regular returns to estrus and variable reductions in litter size were observed. The problem started suddenly and did not appear to be related to the quality of the ejaculates, disease, alterations of body condition or any other apparent reasons. Subsequent studies determined that the problem was the origin of the plastic bags used for semen storage. Chemical analysis of the suspicious bags identified unexpected compounds such as BADGE, a cyclic lactone and an unknown phthalate that leached into the semen at concentrations of 0.2 to 2.5 mg/L. Spermatozoa preserved in these bags passed all of the routine quality control tests and no differences were observed between storage in the control and suspicious bags (p > 0.05). In vitro fecundation tests and endocrine profiler panel analysis (EPP) did not show any alterations, whereas the in vivo tests confirmed the described failure. This is the first described relationship between reproductive failure and toxic compounds released from plastic bags.

Let $\{\mathbb{P}_n\}_{n\ge 0}$ and $\{\mathbb{Q}_n\}_{n\ge 0}$ be two monic polynomial systems in several variables satisfying the linear structure relation $$\mathbb{Q}_n = \mathbb{P}_n + M_n \mathbb{P}_{n-1}, \quad n\ge 1,$$ where $M_n$ are constant matrices of proper size and $\mathbb{Q}_0 = \mathbb{P}_0$. The aim of our work is twofold. First, if both polynomial systems are orthogonal, characterize when that linear structure relation exists in terms of their moment functionals. Second, if one of the two polynomial systems is orthogonal, study when the other one is also orthogonal. Finally, some illustrative examples are presented., 28 pages. To appear in Numerical Algorithms

Packaged food can contain non-intentionally added substances (NIAS) as a result of reaction and degradation processes or the presence of impurities in the raw materials used for the packaging production. This manuscript reviews the evidence of NIAS and their possible origin. One of the most challenging and difficult tasks when a sample of packaging materials arrives at the laboratory is knowing the procedure to apply for identifying the unknown compounds. This work proposes an analytical procedure for sample treatment, applicable to polymers as well as to migration samples, and for NIAS identification. The identification protocol comprises the determination of both volatile and non-volatile compounds. A review is presented of the most novel analytical techniques used for identification purposes, particularly high resolution mass spectrometry (HRMS).

Acrylic adhesives are used to manufacture multilayer laminates that are used in food packaging to form the geometric shape of the package as well as to stick labels on the packages. Once applied on the packaging adhesives can supply potential migrants that could endanger the packaged food. Adhesives are complex matrices where intentionally and non intentionally added substances are present, but the identification of the migrants is required by law. In this study atmospheric pressure gas chromatography coupled to a quadrupole hyphenated to a time of flight mass spectrometer (APGC–MS/Q-TOF) has been explored for identification of unknowns coming from three different acrylic adhesives. The results are compared to those obtained by conventional GC–MS-Q (quadrupole). Sixteen compounds were identified by GC–MS/Q and five of them were confirmed by APGC–MS/Q-TOF as their molecular ions were found. Moreover, additional three new compounds were identified and their structure was elucidated working with the spectra obtained by APGC–MS/Q-TOF. This finding was very relevant as these compounds were biocides suspected to be allergenic and cytotoxic in humans. Migration studies were carried out using Tenax as solid food simulant and the results showed that the three acrylic adhesives tested in this work were safe for being used in food packaging materials since the migration of compounds previously identified was below the limit established in the current legislation.

To assess the predictive value of B-type natriuretic peptide (BNP) in the diagnosis of heart failure (HF) in a primary-care setting in Spain.PANAMA was a multicenter and cross-sectional study. Patients ≥18 years of age with a clinical diagnosis of HF (Framingham criteria) were consecutively included in the study by primary-care investigators. BNP determination and an echocardiogram were performed in every patient. The cut-off point of BNP for the criterion of exclusion of HF was considered as100 pg/ml, as suggested by European guidelines. Sensitivity, specificity, positive-predictive value and negative-predictive value were calculated.A total of 72 patients (mean age: 75.1 ± 8.7 years; 74.6% women) were included. The most frequent associated risk factors were hypertension (75.6%) and dyslipidemia (54.3%). The most common major and minor criteria of HF according to Framingham criteria were radiographic cardiomegaly (90.2%) and dyspnea on ordinary exertion (100%), respectively. BNP median was 49 pg/ml (33.3 pg/ml in those with a doubtful diagnosis of HF and 83.3 pg/ml in those with a likely diagnosis of HF). Approximately 60% of patients exhibited diastolic dysfunction. Concerning accuracy parameters comparing BNP100 pg/ml with echocardiogram, sensitivity was 25%, the specificity 80.8%, and the positive- and negative-predictive values were 68.8 and 38.9%, respectively.In patients attended by general practitioners, BNP100 pg/ml may be a useful diagnostic tool with a high specificity for the diagnosis of HF.

[EN] Ethylene vinyl alcohol copolymer (EVOH) films containing green tea extract were successfully produced by extrusion. The films were brown and translucent, and the addition of the extract increased the water and oxygen barrier at low relative humidity but increased the water sensitivity, the glass transition temperature, and the crystallinity of the films and improved their thermal resistance. An analysis by HPLC revealed that the antioxidant components of the extract suffered partial degradation during extrusion, reducing the content of catechin gallates and increasing the concentration of free gallic acid. Exposure of the films to various food simulants showed that the liquid simulants increased their capacity to reduce DPPH¿ and ABTS¿+ radicals. The release of green tea extract components into the simulant monitored by HPLC showed that all compounds present in the green tea extract were partially released, although the extent and kinetics of release were dependent on the type of food. In aqueous food simulants, gallic acid was the main antioxidant component released with partition coefficient values ca. 200. In 95% ethanol (fatty food simulant) the K value for gallic acid decreased to 8 and there was a substantial contribution of catechins (K in the 1000 range) to a greatly increased antioxidant efficiency. Kinetically, gallic acid was released more quickly than catechins, owing to its faster diffusivity in the polymer matrix as a consequence of its smaller molecular size, although the most relevant effect is the plasticization of the matrix by alcohol, increasing the diffusion coefficient >10-fold. Therefore, the materials here developed with the combination of antioxidant substances that constitute the green tea extract could be used in the design of antioxidant active packaging for all type of foods, from aqueous to fatty products, the compounds responsible for the protection being those with the higher compatibility with the packaged product., We acknowledge the financial support of the Spanish Ministry of Science and Innovation, Projects AGL2006-02176, AGL2009-08776, and Fun-C-Food CSD2007-00063, and the C.L.d.D. fellowship (FPU program).

Different analytical methods were optimized and applied to quantify certain surrogate contaminants (toluene, chlorobenzene, phenol, limonene and benzophenone) in samples of contaminated and recycled flakes and virgin pellets of polyethylene terephthalate (PET) coming from the industrial challenge test. A screening analysis of the PET samples was carried out by direct solid-phase microextraction (SPME) in headspace mode (HS). The methods developed and used for quantitative analysis were a) total dissolution of PET samples in dichloroacetic acid and analysis by HS-SPME coupled to gas chromatography-mass spectrometry (GC-MS) and, b) dichloromethane extraction and analysis by GC-MS. The concentration of all surrogates in the contaminated PET flakes analyzed by HS-SPME method was lower than expected according to information provided by the supplier. Dichloroacetic acid interacted with the surrogates, resulting in a tremendous decrease of limonene concentration. The degradation compounds from limonene were identified. Dichloromethane extraction and GC-MS analysis evidenced the highest values of analytes in these PET samples. Based on the foregoing data, the efficiency of the recycling process was evaluated, whereby the removal of 99.9% of the surrogates proceeding from the contaminated flakes was confirmed.

Let V ( z ) = ∏ j = 1 m ( z − ζ j ) , ζ h ≠ ζ k , h ≠ k and | ζ j | = 1 , j = 1 , … , m , and consider the polynomials orthogonal with respect to | V | 2 d μ , φ n ( | V | 2 d μ ; z ) , where μ is a finite positive Borel measure on the unit circle with infinite points in its support, such that the reciprocal of its Szegő function has an analytic extension beyond | z | 1 . In this paper we deduce the asymptotic behaviour of their Verblunsky coefficients. By means of this result, an asymptotic representation for these polynomials inside the unit circle is also obtained.

The existence of sequences of orthogonal polynomials on the unit circle whose zeros are everywhere dense in ¦z¦ ⩽ 1 is proved.

In this paper, we obtain a result about the asymtotic behavior of the orthogonal polynomials on the unit circle in the so-called case C.