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Plasma Atomic Emission Spectrometry (plasma + atomic_emission_spectrometry)
Selected AbstractsFlux growth of La-doped lead zirconate stannate titanate antiferroelectric crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 10 2008Lin Wang Abstract Relaxor antiferroelectric single crystals lead lanthanum zirconate stannate titanate (PLZST) with the composition around the morphotropic phase boundary (MPB) have been grown by flux method using 50 wt% PbO-PbF2 -B2O3 as a flux. The obtained crystals are light yellow in color. The XRD patterns revealed that the habitual faces of the obtained crystal are (001). The crystal morphology was studied and related to a layer growth mechanism controlled by two-dimensional growth. The chemical composition of as-grown crystal was analyzed by inductively coupled plasma atomic emission spectrometry (ICP), indicating a slight decrease of the amount of Ti compared to the starting materials. The result was verified by the XRD patterns with the phase transformation from the co-existence of tetragonal and rhombohedra phases to the single tetragonal phase. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Comparison of some properties on the different types of pestil: a traditional product in TurkeyINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2005Ozlem Cagindi Summary Pestil is a traditional dried fruit snack, which is consumed in Turkey. Wheat starch is mixed with different clarified fruit juices such as grape, mulberry, apricot or plum and cooked using traditional techniques. In this work the proximate chemical composition (moisture, ash, fat, crude protein and total carbohydrate), energy value and thickness of grape, apricot and mulberry pestils were investigated. The colour properties (Hunter L, a and b) were determined by a Minolta Chroma-Meter and the mineral content (Ca, Fe, K, Mg, Na, Cu, Zn, Mn) of each product was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The carbohydrate value of pestil samples ranged between 73.7 and 82.4% and energy value was between 321.5 and 356.4 kcal 100 g,1. Mulberry pestil was a better source of energy than grape and apricot pestils. Apricot pestils were rich in calcium, sodium and zinc, and mulberry pestil samples were rich in magnesium. [source] Ion imprinted polymer particles for separation of yttrium from selected lanthanidesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 9 2006Ramakrishnan Kala Abstract Lanthanide(III) (Dy, Gd, Tb and Y) ion imprinted polymer (IIP) materials were synthesized via single pot reaction by mixing lanthanide imprint ion with 5,7-dichloroquinoline-8-ol, 4-vinylpyridine, styrene, divinylbenzene and 2,2,-azobisisobutyronitrile in 2-methoxyethanol porogen. The imprint ion was removed by stirring the above materials (after powdering) with 6 mol/L HCl to obtain the respective lanthanide IIP particles. Y-Dy, Y-Gd and Dy-Gd polymer particles were obtained by physically mixing equal amounts of the respective leached individual lanthanide(III) particles. Control polymer (CP) particles were similarly prepared without imprint ion. Application of the above synthesized polymer particles was tested for separation of Y from Dy, Gd and Tb employing batch and column SPE methods using inductively coupled plasma atomic emission spectrometry for the determination. Optimization studies show that Y present in 500 mL can be preconcentrated using Dy-Gd IIP particles and eluted with 20 mL of 1.0 mol/L of HCl, providing an enrichment factor of , 25. Dy-Gd IIP particles offer higher selectivity coefficients for Y over other lanthanides compared to other IIP particles and commercial liquid,liquid extractants. Selectivity studies for Y over other coexisting inorganic species (other than lanthanides) were also conducted and the results obtained show a quantitative separation of Y from other inorganics other than Cu(II) and Fe(III). Furthermore, both batch and column studies indicate the purification of yttrium concentrate from 55.0 ± 0.2 to 65.2 ± 0.2% in a single stage of operation. [source] Differentiation of eight tea (Camellia sinensis) cultivars in China by elemental fingerprint of their leavesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2009Yingxu Chen Abstract BACKGROUND: Tea is an infusion made from dried leaves of tea (Camellia sinensis) and can be a good dietary source of essential trace metals for humans. Therefore, it is necessary to consider variations in element content of tea leaves among tea cultivars. Thus, elemental fingerprint techniques, based on elemental contents (Al, B, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, and Zn) determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and multivariate statistical analysis, have been used to differentiate eight tea cultivars. RESULTS: The ranges of element concentrations in leaves of the eight cultivars were in good agreement with those obtained in previous studies and the level of most elements in tea leaves was significantly different among cultivars. The classifications of eight tea cultivars were 100% accurate in total by principal component analysis (PCA), hierarchical cluster analysis (HCA), linear discriminant analysis (LDA), and back-propagation neural network (BPNN) analysis. CONCLUSION: Each cultivar presented a distinctive element fingerprint and the elements in tea leaves can be significant predictors in differentiating tea cultivars. Copyright © 2009 Society of Chemical Industry [source] Volatile organoselenium monitoring in production and gastric digestion processes of selenized yeast by solid-phase microextraction-multicapillary gas chromatography coupled microwave-induced plasma atomic emission spectrometry,APPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2004J. Sanz Landaluze Abstract Evolution of volatile organoselenium compounds in the production and gastric digestion of selenized yeast has been monitored. The industrial production of these kinds of material, employed as food supplements, has been simulated in a process of yeast enrichment with inorganic selenium selenium (IV) in different growth media, with variation of the pH value. The in vitro gastric digestion process was carried out with pepsin in an acid and salt mixture. Determination of volatile species of selenium was achieved coupling solid-phase microextraction (SPME) for preconcentration and sample,matrix separation and microwave-induced plasma atomic emission spectrometry, in combination with multicapillary (MC) gas chromatography for separation and detection of the selenium species. The MC column was operated at low temperatures (,30 °C). The method was optimized, using a chemometric approach, with respect to the detection of organoselenium species such as dimethylselenide, diethylselenide and dimethyldiselenide. SPME sampling was carried out in the headspace above the corresponding solutions. Separation is fast, with a chromatogram being obtained in less than 5 min, and the detection limits were at the low parts per billion level for all species investigated. The results of the yeast enrichment process demonstrate inorganic selenium transformation into volatile organic species. The presence of inorganic selenium gave rise to at least five different volatile species after metabolization by yeast, with dimethylselenide and dimethyldiselenide being the predominant species. Commercial pasteurized yeast, containing mainly selenomethionine for use as a food supplement, and tablets were found to be still active under conditions of the simulation of the digestion process, even though producing relatively low amounts of organoselenium compounds. Copyright © 2004 John Wiley & Sons, Ltd. [source] Nutrients apparent digestibility coefficients of selected protein sources for juvenile Siberian sturgeon (Acipenser baerii Brandt), compared by two chromic oxide analyses methodsAQUACULTURE NUTRITION, Issue 6 2009H. LIU Abstract Apparent digestibility coefficients (ADCs) of dry matter (ADCd), crude protein (ADCp), energy (ADCe) and amino acids in selected feedstuffs were determined for juvenile Siberian sturgeon (8.38 ± 0.20 g). The tested feedstuffs were fishmeal (FM), meat and bone meal (MBM), poultry by-product meal, hydrolysed feather meal, fermented feather meal solvent-extracted cottonseed meal and soybean meal. ADCs were determined using a reference diet and test diets at 7 : 3 ratios with 5 g kg,1 chromic oxide (Cr2O3) as an inert marker. Fish were reared in a recirculating system and fed to apparent satiation five times daily. Cr2O3 in diets and faeces samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and acid-digestion colorimetry (AC) methods, respectively. The results showed that ICP-AES method was more accurate for Cr2O3 determination than AC method, and the results determined by ICP-AES method were used in this study. ADCd and ADCp of seven tested ingredients were lowest for MBM (59.1 and 84.5%) and highest for FM (79.9 and 94.5%); ADCe of tested ingredients were from 71.8% for SECM to 93.2% for FM. ADCs of amino acid in test ingredients followed similar trend to the ADCp. The ADCs of individual amino acids varied from 61.6% (histidine in MBM) to 98.8% (valine in FM). [source] Comparison of Artificial Neural Networks with Partial Least Squares Regression for Simultaneous Determinations by ICP-AESCHINESE JOURNAL OF CHEMISTRY, Issue 11 2007Mohamad KHAYATZADEH MAHANI Abstract Simultaneous determination of several elements (U, Ta, Mn, Zr and W) with inductively coupled plasma atomic emission spectrometry (ICP-AES) in the presence of spectral interference was performed using chemometrics methods. True comparison between artificial neural network (ANN) and partial least squares regression (PLS) for simultaneous determination in different degrees of overlap was investigated. The emission spectra were recorded at uranium analytical line (263.553 nm) with a 0.06 nm spectral window by ICP-AES. Principal component analysis was applied to data and scores on 5 dominant principal components were subjected to ANN. A 5-5-5 (input, hidden and output neurons) network was used with linear transfer function after both hidden and output layers. The PLS model was trained with five latent variables and 20 samples in calibration set. The relative errors of predictions (REP) in test set were 3.75% and 3.56% for ANN and PLS respectively. [source] | ||||||||||