2,695 research outputs found

    Multi-Element Analysis of Spanish Date Palm (Phoenix dactylifera L.) by Inductively Coupled Plasma-Based Techniques. Discrimination Using Multivariate Statistical Analysis

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    The elemental analysis of Spanish palm dates by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry is reported for the first time. To complete the information about the mineral composition of the samples, C, H, and N are determined by elemental analysis. Dates from Israel, Tunisia, Saudi Arabia, Algeria and Iran have also been analyzed. The elemental composition have been used in multivariate statistical analysis to discriminate the dates according to its geographical origin. A total of 23 elements (As, Ba, C, Ca, Cd, Co, Cr, Cu, Fe, H, In, K, Li, Mg, Mn, N, Na, Ni, Pb, Se, Sr, V, and Zn) at concentrations from major to ultra-trace levels have been determined in 13 date samples (flesh and seeds). A careful inspection of the results indicate that Spanish samples show higher concentrations of Cd, Co, Cr, and Ni than the remaining ones. Multivariate statistical analysis of the obtained results, both in flesh and seed, indicate that the proposed approach can be successfully applied to discriminate the Spanish date samples from the rest of the samples tested

    Insight into the origin of carbon matrix effects on the emission signal of atomic lines in inductively coupled plasma optical emission spectrometry

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    In inductively coupled plasma optical emission spectrometry (ICP-OES), the presence of carbon in the matrix strongly affects (positively and negatively) the emission signal of atomic lines. However, the emission signal of ionic lines is mostly unaffected by this concomitant. The goal of this work is to gain insight into the origin of carbon matrix effects on the signal of atomic lines in ICP-OES. To this end, the emission signal of a total of 3608 lines (i.e., 1755 atomic and 1853 ionic lines) of 62 elements (Ag, Al, As, Au, B, Ba, Be, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hg, Ho, I, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Pd, Pr, Pt, Re, Rh, S, Sb, Sc, Se, Sm, Sn, Sr, Tb, Te, Th, Ti, Tm, U, V, Y, Yb, Zn and Zr) were registered for carbon containing solutions (20 g L−1) prepared from glycerol. Results were compared to those obtained operating a 1% w w−1 HNO3 solution. Compared to the HNO3 reference solution, emission signals for As, B, Hg, I, P, Se and Te atomic lines were increased for the carbon containing solution. However, signal suppression was noticed for the signal emission of Ag, Al, Ba, Be, Ca, Cd, Co, Cr, Cs, Eu, Fe, Ga, Ge, K, Ho, In, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Ni, Pb, Pd, Pr, Pt, Re, Rh, S, Sb, Sc, Sn, Sr, Ti, Tm, V, Y and Zr atomic lines. No measurable matrix effects within experimental uncertainties were registered for Au, Cu, Ir, Gd and Zn atomic lines. As regards Ce, Dy, Er, Nd, Sm, Tb, Th, U and Yb no clear conclusion about matrix effects was feasible due to the limited atomic emission wavelengths monitored. Experimental results showed that the intensity of matrix effects depends on both analyte ionization energy and the energy of the electronic upper level involved in the electronic transition. Matrix effects on atomic emission lines can be explained by the simultaneous occurrence of different mechanisms: (i) charge transfer reactions; (ii) collisional ionization; and (iii) collisional excitation with carbon-based species. Because these mechanisms mostly affect analyte atomic population, carbon matrix effects are more significant on the emission signal of atomic lines rather than ionic ones. Finally, the judicious analyte wavelength selection is critical to minimize carbon matrix effects for those elements for which the most sensitive wavelength is atomic (i.e., Se and alkali elements). On this regard, the selection of the internal standard should consider both the ionization energy and the energy of the electronic upper level of the analyte.Authors would like to express their appreciation to the University of Alicante (Projects VIGROB-050, UADIF17-42 and UAUSTI16-02) for financial support

    Evaluación de diferentes metodologías para el análisis elemental de vinos mediante técnicas de espectrometría atómica de plasma

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    Póster presentado en el V Congreso Nacional de Ciencia y Tecnología de los Alimentos, Murcia, 26-29 mayo 2009

    Introduction of organic solvent solutions into inductively coupled plasma-atomic emission spectrometry using a microwave assisted sample introduction system

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    A microwave assisted sample introduction system based on the use of a TM010 cavity (MWDS2) has been employed for the introduction of 10% w/w organic solvent solutions in inductively coupled plasma atomic emission spectrometry (ICP-AES). Ethanol, propan-2-ol, formic and acetic acids have been used. Firstly, the effect of the incident microwave power and the sample uptake rate on the emission signal was evaluated. For all matrices tested, the higher emission signals were obtained when operating at the highest microwave power (i.e., 290 W) and sample uptake rate (400 mL/min). Results with the MWDS2 were compared with those afforded by a desolvation system based on the use of a domestic microwave oven (MWDS) and by a conventional sample introduction system (CS). The MWDS2 provides the highest emission signals (up to 7 and 17 times higher than those with the MWDS and the CS, respectively). As regards the matrix effects originated by the organic solutions, results demonstrate that the use of a microwave-based sample introduction system, mainly the MWDS2, affords a noticeable reduction in the matrix effects originated by the use of organic solvent solutions in ICP-AES with a conventional sample introduction system. This behaviour can be explained by taking into account the solution transport rates afforded by the different sample introduction systems. For all the analytical lines and matrices tested and operating at 400 mL/min, the MWDS2 gives rise to signal values that are, on average, 1.2 times the signal obtained with water. For the MWDS and the CS, this factor takes values of 1.6 and 2.0, respectively. Transient matrix effects have been observed operating with the MWDS2 when switching between water and an organic matrix solution. These transient effects result in a drift time about 4.5 times higher than those with a CS

    Rapid detection and quantitation of viral hemorrhagic septicemia virus in experimentally challenged rainbow trout by real-time RT-PCR

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    A quantitative real-time RT-PCR (Q-RT-PCR) was developed to detect and determine the amount of viral hemorrhagic septicemia virus (VHSV) in organs of experimentally infected rainbow trout. Primers and TaqMan probes targeting the glycoprotein (G) and the nucleoprotein (N) genes of the virus were designed. The efficiency, linear range and detection limit of the Q-RT-PCR were assessed on cell cultured virus samples. VHSV N gene amplification was more efficient and more sensitive than the VHSV G amplicon. On cell culture grown virus, samples could be accurately assayed over a range of seven logs of infectious particles per reaction. To demonstrate the utility of Q-RT-PCR in vivo, bath infection trials were carried out and samples from fish spleen, kidney, liver and blood were harvested and tested for VHSV. Q-RT-PCR was a more reliable method than either conventional RT-PCR or the cell culture assay for virus diagnosis. Results of VHSV RNA detection in fish shortly after infection as well as on asymptomatic fish several weeks after experimental challenge are presented here. This is the first report showing the utility of Q-RT-PCR for VHSV detection and quantitation both in vitro and in vivo. The suitability of this method to test the efficacy of antiviral treatments is also discussed

    Evaluation of MIP-OES as a detector in DLLME procedures: application to Cd determination in water samples

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    High-power microwave induced plasma optical emission spectrometry (MIP-OES) constitutes a serious alternative to inductively coupled plasma optical emission spectrometry (ICP-OES) for elemental analysis. To improve the analytical capabilities of MIP-OES, dispersive liquid–liquid microextraction (DLLME) procedures seems to be, a priori, a very promising choice for trace and ultra-trace analysis in complex matrices. Nevertheless, to date, DLLME has never been coupled to MIP-OES. The goal of the present work is to investigate the capability of MIP-OES as a detector in DLLME procedures. To this end, spectral and non-spectral interferences caused by the presence of common DLLME extractants (i.e., chloroform and supramolecular solvent based on 1-decanol and THF) in MIP-OES have been evaluated. Results reveal the occurrence of both spectral and non-spectral interferences due to carbon-based molecular bands emission in MIP-OES. Carbon-based molecular emission (i.e. C2 and CH) significantly affects analyte wavelengths above 328 nm. By the appropriate selection of experimental conditions (i.e. analyte wavelength and nebulizer gas flow rate), both spectral and non-spectral interferences could be mitigated allowing elemental analysis by means of DLLME-MIP-OES. Different DLLME methodologies have been developed for Cd determination in water samples (i.e., tap, sparkling and synthetic seawater) by MIP-OES. These methodologies afford an enrichment factor of 46 and 42 for chloroform and supramolecular-based solvent DLLME procedures, respectively, and a limit of detection (LoD) of 1 μg L−1. This LoD is 100-fold lower than that obtained by conventional MIP-OES (i.e. no DLLME) due to both analyte preconcentration and the beneficial effect of organics on aerosol generation and transport. These analytical figures of merit are equivalent to those previously reported for DLLME-ICP-OES and allows Cd determination in water samples according to current international policies.The authors would like to thank the Generalitat Valenciana (CONSELLERIAAGRICULTURA4-17T) and the University of Alicante (VIGROB-050; UADIF17-42; UAUSTI16-02) for the financial support of this work

    Elemental bioavailability in whey protein supplements

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    Whey protein (WP) as a dietary supplement for athletes and gym-users is characterized by a content of high-quality amino acids. The benefits of their consumption are well-known and mainly related to the improvements of strength and body composition. Nevertheless, there is a scarce information about the risk associated to their elemental composition. The aim was to evaluate the total content and bioavailability of twenty-five elements in twenty whey protein powder samples, using Inductively Coupled Plasma Mass Spectrometry, and to evaluate the possible risk associated to the excessive daily intake of such products. Results showed that Na, K, Ca and Mg were the most predominant elements. After Hierarchical Cluster Analysis three different groups of whey protein supplements were observed. ANOVA analysis indicates that the concentration of the Na, K and Mg above mentioned elements is the key for the observed classification. The average elemental bioavailable fraction in the stomach is 45 % whereas in the intestine is 64 %. Most of the elements tested (nineteen) show gastric bioavailability higher than 60 %, being Al the lowest (37 %) and Co the highest one (76 %). According to our results, previously published data and recommendations of producers, WP samples can be considered save from the elemental composition point of view

    Determination of metallic nanoparticles in air filters by means single particle inductively coupled plasma mass spectrometry

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    Single particle inductively coupled plasma mass spectrometry (spICP-MS) has been explored for the determination of metallic nanoparticles (NPs) in air. Different extraction strategies (i.e., direct immersion, hard cap espresso, ultrasound-assisted and microwave-assisted extraction) and extracting solvents (i.e., citric acid, trisodium citrate, potassium nitrate, sodium nitrate, thiourea, disodium pyrophosphate and ammonium hydroxide) were investigated for platinum and gold NPs recovery from glass and microquartz fiber filters with a nominal size cut-off of 300 nm. Results show that metallic NPs are preserved and quantitatively extracted from the filter in 4 min inside an 800 W microwave oven by using 40 mL of a 2.0% w w−1 NH4OH solution. For the remaining extraction procedures, either incomplete recoveries or NPs degradation occur. As regards the influence of filter material, microquartz fiber affords better NPs capturing performance than glass fiber ones, enabling the quantification of NPs with diameters above 28 nm. This methodology has been successfully applied to determine PtNPs in filters from environmental monitoring stations and to gain insight into NPs transport through ICP-MS sample introduction system. Care should be taken during spICP-MS calibration since biased results might be obtained due to differences on NPs transport efficiency between standards and samples.The authors would like to thank the Generalitat Valenciana (PROMETEO/2021/055) and the Vice-Presidency for Research and Knowledge Transfer of the University of Alicante for the financial support of this work (Projects GRE12-19 and VIGROB-050). D. Torregrosa thanks the Spanish Ministerio de Ciencia, Innovación y Universidades for the fellowship FPU17/02853

    A Cross-Sectional Study of Prisoners in Mexico City Comparing Prevalence of Transmissible Infections and Chronic Diseases with That in the General Population.

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    ObjectivesTo describe patterns of transmissible infections, chronic illnesses, socio-demographic characteristics and risk behaviors in Mexico City prisons, including in comparison to the general population, to identify those currently needing healthcare and inform policy.Materials and methodsA cross-sectional study among 17,000 prisoners at 4 Mexico City prisons (June to December 2010). Participation was voluntary, confidential and based on informed consent. Participants were tested for HIV, Hepatitis B & C, syphilis, hypertension, obesity, and, if at risk, glucose and cholesterol. A subset completed a questionnaire on socio-demographic characteristics and risk behaviors. Positive results were delivered with counseling and treatment or referral.Results76.8% (15,517/20,196) of men and 92.9% (1,779/1,914) of women participated. Complete data sets were available for 98.8%. The following prevalence data were established for transmissible infections: HIV 0.7%; syphilis: Anti-TP+/VDRL+ 2.0%; Hepatitis B: HBcAb 2.8%, HBsAg 0.15%; Anti-HCV 3.2%. Obesity: 9.5% men, 33.8% women. Compared with national age- and sex-matched data, the relative prevalence was greater for HIV and syphilis among women, HIV and Hepatitis C in men, and all infections in younger participants. Obesity prevalence was similar for women and lower among male participants. The prevalence of previously diagnosed diabetes and hypertension was lower. Questionnaire data (1,934 men, 520 women) demonstrated lower educational levels, increased smoking and substance use compared to national data. High levels of non-sterile tattooing, physical abuse and histories of sexual violence were found.ConclusionThe study identified that health screening is acceptable to Mexico City prisoners and feasible on a large-scale. It demonstrated higher prevalence of HIV and other infections compared to national data, though low rates compared to international data. Individual participants benefited from earlier diagnosis, treatment and support. The data collected will also enable the formulation of improved policy for this vulnerable group

    The role of Cymodocea nodosa on the dynamics of trace elements in different marine environmental compartments at the Mar Menor Lagoon (Spain)

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    During mining activities historically developed at Sierra Minera (Cartagena-La Unión, Spain), high amounts of trace elements were discharged to the Mar Menor coastal lagoon mainly through El Beal Wadi. The objective of this study is to establish the role played by the Cymodocea nodosa in the coastal marine dynamics of trace elements at the mouth of the wadi. To this end, the content of nine trace elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in different marine environmental compartments (i.e. marine and coastal sediments, C. nodosa tissues collected from live seagrass and C. nodosa beach cast litter) at two different locations were determined by inductively coupled plasma atomic emission spectrometry. The results showed that the seagrass C. nodosa could mobilise part of the elements present in marine sediments and water, thereby causing their re-accumulation in the coastal sediments through the C. nodosa beach cast litter.The authors thanks the University of Alicante – Spain for the financial support (VIGROB-050)
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