共查询到20条相似文献,搜索用时 31 毫秒
1.
García-Ruiz S Moldovan M Fortunato G Wunderli S García Alonso JI 《Analytica chimica acta》2007,590(1):55-66
In order to evaluate alternative analytical methodologies to study the geographical origin of ciders, both multi-elemental analysis and Sr isotope abundance ratios in combination with multivariate statistical analysis were estimated in 67 samples from England, Switzerland, France and two Spanish regions (Asturias and the Basque Country). A methodology for the precise and accurate determination of the 87Sr/86Sr isotope abundance ratio in ciders by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) was developed. Major elements (Na, K, Ca and Mg) were measured by ICP-AES and minor and trace elements (Li, Be, B, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Mo, Cd, Sn, Sb, Cs, Ba, La, Ce, W, Tl, Pb, Bi, Th and U) were measured by ICP-MS using a collision cell instrument operated in multitune mode. An analysis of variance (ANOVA test) indicated that group means for B, Cr, Fe, Ni, Cu, Se, Cd, Cs, Ce, W, Pb, Bi and U did not show any significant differences at the 95% confidence level, so these elements were rejected for further statistical analysis. Another group of elements (Li, Be, Sc, Co, Ga, Y, Sn, Sb, La, Tl, Th) was removed from the data set because concentrations were close to the limits of detection for many samples. Therefore, the remaining elements (Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba) together with 87Sr/86Sr isotope abundance ratio were considered for principal component analysis (PCA) and linear discriminant analysis (LDA). Finally, LDA was able to classify correctly 100% of cider samples coming from different Spanish regions, France, England and Switzerland when considering Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba and 87Sr/86Sr isotope abundance ratio as original variables. 相似文献
2.
Magdalena Gajek Aleksandra Pawlaczyk Malgorzata I. Szynkowska-Jozwik 《Molecules (Basel, Switzerland)》2021,26(1)
Wine is one of the most popular alcoholic beverages. Therefore, the control of the elemental composition is necessary throughout the entire production process from the grapes to the final product. The content of some elements in wine is very important from the organoleptic and nutritional points of view. Nowadays, wine studies have also been undertaken in order to perform wine categorization and/or to verify the authenticity of products. The main objective of this research was to evaluate the influence of the chosen factors (type of wine, producer, origin) on the levels of 28 elements in 180 wine samples. The concentration of studied elements was determined by ICP-MS (Ag, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Rb, Sb, Sn, Sr, Te, Tl, U, Zn), ICP-OES (Ca, Fe, K, Mg, Ti), and CVAAS (Hg) techniques in 79 red, 75 white, and 26 rose wine samples. In general, red wines contained higher values of mean and median of B, Ba, Cr, Cu, Mn, Sr and Zn in contrast to other wine types (white and rose). In white wines (when compared to red and rose wines) higher levels of elements such as Ag, Be, Bi, Cd, Co, Li, K and Ti were determined. In contrast, rose wines were characterized by a higher concentration of Fe and U. The study also revealed that in the case of 18 samples, the maximum levels of some metals (Cd—8 samples, Pb—9 samples, Cu—1 sample) were slightly exceeded according to the OIV standards, while for Zn and Ti in any wine sample the measured concentrations of these metals were above the permissible levels. Thus, it can be stated that the studied wines contained, in general, lower levels of heavy metals, suggesting that they should have no effect on the safety of consumption. The results also showed higher pH level for red wines as a consequence of the second fermentation process which is typically carried out for this type of wine (malolactic fermentation). The highest median value of pH was reported for Merlot-based wines, while the lowest was for Riesling. It is assumed that dry Riesling has a higher content of tartaric and malic acid than dry Chardonnay grown in the same climate. From all of the studied countries, wines from Poland seemed to present one of the most characteristic elemental fingerprints since for many elements relatively low levels were recorded. Moreover, this study revealed that also wine samples from USA and Australia can be potentially discriminated from the rest of studied wines. For USA the most characteristic metal for positive identification of the country of origin seems to be uranium, whereases for Australia – strontium and manganese. Based on the highly reduced set of samples, it was not possible to differentiate the studied wine products according to the grape variety other than Syrah, and partially Chardonnay. Since all the Syrah-based samples originated from the same country (Australia) thus, the observed grouping should be more related with the country of origin than the grape variety. 相似文献
3.
Chemometric characterisation of Basque and French ciders according to their polyphenolic profiles 总被引:3,自引:0,他引:3
Alonso-Salces RM Guyot S Herrero C Berrueta LA Drilleau JF Gallo B Vicente F 《Analytical and bioanalytical chemistry》2004,379(3):464-475
Polyphenolic compositions of Basque and French ciders were determined by HPLC-DAD following thiolysis, in order to characterise and differentiate these beverages and then develop a classification system capable of confirming the authenticities of both kinds of cider. A data set consisting of 165 cider samples and 27 measured features was evaluated using multivariate chemometric techniques, such as cluster analysis and principal component analysis, in order to perform a preliminary study of data structure. Supervised pattern recognition techniques such as linear discriminant analysis (LDA), K-nearest neighbours (KNN), soft independent modelling of class analogy (SIMCA), and multilayer feed-forward artificial neural networks (MLF-ANN) attained classification rules for the two categories using the chemical data, which produced satisfactory results. Authentication systems obtained by combining two of these techniques were proposed. We found that SIMCA and LDA or KNN models achieved 100% hit-rates, since LDA and KNN permit the detection of every Basque cider and SIMCA provides a model for Basque cider that excludes all French ciders. Polyphenolic profiles of the ciders provided enough information to be able to develop classification rules for identifying ciders according to their geographical origin (Basque or French regions). Chemical and organoleptic differences between these two types of cider are probably due to the original and distinctive cidermaking technologies used for their elaboration. Using polyphenic profiles, about 80% of French ciders could be distinguished according to their region of origin (Brittany or Normandy). Although their polyphenolic profiles did not provide enough information to achieve an authentication system for Breton and Norman ciders.Abbreviations AVI
Avicularin - CQA
Caffeoylquinic acid - CAF
Caffeic acid - CAT
(+)-catechin - CT-1, -2, -3
Unknown flavan-3-ols - DPn
Average degree of polymerization of procyanidins - EC
(–)-epicatechin - HCA-7
Ferulic acid - HCA-1, -2 ,-3, 4, -5, -6
Unknown hydroxycinnamic acids - HYP
Hyperin - IQC
Isoquercitrin - PC
Total procyanidins - PCM
p-Coumaric acid - PCQ
p-Coumaroylquinic acid - PL
Phloretin - PLG
Phloridzin - PLXG
phloretin-2-O-xyloglucoside - PPO
Polyphenoloxidase - QCE
Quercetin - QCI
Quercitrin - RUT
Rutin - CA
Cluster analysis - KNN
K-nearest neighbours - LDA
Linear discriminant analysis - MLF-ANN
Multilayer feed-forward-artificial neural network - PCA
Principal component analysis - PC1
First principal component - PC2
Second principal component - PC3
Third principal component - RMSE
Root medium square error - SD
Standard deviation - SIMCA
Soft independent modelling of class analogy - DAD
Diode array detector - HPLC
High Performance Liquid Chromatography - ND
Not detected 相似文献
4.
U. Tomza 《Journal of Radioanalytical and Nuclear Chemistry》1987,119(5):387-396
Instrumental neutron activation analysis /INAA/ method was applied to measure major, minor and trace elements in 34 samples of hard and brown coal originating from eight Polish coal mines. The elemental concentrations of 38 elements /Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Mo, Ag, Cd, In, Sb, I, Cs, Ba, La, Ce, Sm, Eu, Lu, W, Au and Th/ are presented and compared with published data for coals from various origin. Enrichment factors, calculated relative to iron and the average crustal rock composition, indicated that several elements are highly enriched in Polish coals. 相似文献
5.
The composition of vodkas, rectified food alcohols, cognacs, cognac spirits, and other strong alcoholic beverages was studied by chromatography and compared with the composition of industrial (synthetic and hydrolysis) ethyl alcohols, adulterated cognacs, and homemade spirits (samogon) from the illicit market. It was found that the majority of the test alcohol-containing liquids were close to commercial alcoholic beverages in terms of chemical composition and toxic properties. The samples containing ethylene glycol and enriched components of the head fraction of rectification should be considered most toxic. 相似文献
6.
Determination of elemental fingerprint profile of 40 commercial beer samples was performed using inductively coupled plasma–mass
spectrometry combined with principal component analysis and receiver operating characteristic (ROC) analysis. Fourteen trace
elements, 51V, 52Cr, 59Co, 60Ni, 75As, 82Se, 95Mo, 111Cd, 115In, 121Sb, 133Cs, 208Pb, 209Bi, and 238U, were monitored. All 40 beer samples are distinguishable by using the proposed method. ROC analysis showed that individual
beer samples can be correctly identified via the magnitude of its correlation coefficient with respect to the other beers
with low false positive rate. The obtained results suggested that the elemental fingerprint technique is feasible for sample
differentiation and comparison. 相似文献
7.
8.
R. Schelenz 《Journal of Radioanalytical and Nuclear Chemistry》1977,37(2):539-548
The trace element content of the total daily diet (food and beverages) of each of 4 adult males was determined over a period
of one week. A method of radiochemical neutron activation analysis is briefly described which enables the determination of
up to 31 elements in biological samples. Of the 25 elements determined in the diet 12 are essential elements (Ca, Cl, Co,
Cr, Cu, Fe, K, Mn, Mo, Na, Se, Zn) while 6 (As, Ba, Br, Cd, Hg, Sb) are classified as toxic. The average concentrations of
the toxic trace elements As, Cd and Hg of the diet are below the provisional tolerable dietary intakes recommended by WHO/FAO.
The contents of Cl, Cu, Fe, K, Mn, Na and Zn are adequate to the proposed nutritional requirements. 相似文献
9.
Yinsong Wang Aiguo Li Yuanxun Zhan Lun Wei Yan Li Guilin Zhang Yaning Xie Jing Zhang Yuanmao Zhang Zuci Shan 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(1):247-251
The atmospheric particulate matter samples were collected in Shanghai, China. The X-ray absorption near-edge structure (XANES)
spectra of Cr, Mn, Cu and Zn were measured. The XANES spectroscopy was used as a fingerprint to compare with that of reference
materials to obtain speciation information. The oxidation state of these elements and main chemical components in the samples
were described using the method. The results show that in our samples the oxidation state of Cr is trivalent, Mn mainly exists
in the divalent state, Cu also exists in the divalent state, and Zn mainly exists in the zinc sulfate. For the XANES spectra
of samples with different particle size and from different sampling site, we did not find their obvious differences. When
we compared the XANES spectra of our samples with those of standard reference material SRM 1648, we found that they are similar
in regards to the determined elements. The elemental concentrations in the samples were determined by proton induced X-ray
emission (PIXE). The difference of elemental concentrations was observed in the different samples. 相似文献
10.
Determination of ink photoinitiators in packaged beverages by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry 总被引:2,自引:0,他引:2
Sagratini G Caprioli G Cristalli G Giardiná D Ricciutelli M Volpini R Zuo Y Vittori S 《Journal of chromatography. A》2008,1194(2):213-220
A new analytical method, using gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) techniques, was developed for the determination in packaged food beverages of five ink photoinitiator residues: 2-isopropylthioxanthone (ITX), benzophenone, 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB), 1-hydroxycyclohexyl-1-phenyl ketone (IRGACURE 184) and ethyl-4-dimethylaminobenzoate (EDAB). Samples were extracted from selected beverages (milk, fruit juices and wine) and relative packagings, using n-hexane and dichloromethane, respectively, purified on solid-phase extraction (SPE) silica gel cartridges, and then analyzed in GC/MS and LC/MS. The recovery percentages, obtained spiking the beverage samples at concentrations of 4 and 10 microgl(-1) with a standard mixture of photoinitiators, were in the range 42-108% (milk), 50-84% (wine), and 48-109% (fruit juices). The repeatability of the method was assessed in all cases by the % of correlation value, that was lower than 19%. The lowest limits of detection (LODs) and limits of quantification (LOQs), obtained using GC/MS, were in the range 0.2-1 and 1-5 microgl(-1), respectively. The method was applied to the analysis of forty packaged food beverages (milk, fruit juices and wine samples). The most significant contamination was that of benzophenone, found in all samples in a concentration range of 5-217mugl(-1). Its presence was confirmed by an LC/Atmospheric-Pressure PhotoIonization (APPI)/MS/MS analysis. The photoinitiator (EHDAB) was found in eleven out of forty beverages in a concentration range of 0.13-0.8 microgl(-1). Less important was the ITX contamination, found in three out of forty samples in a range 0.2-0.24 microgl(-1). The work proposes a new method to analyze ink photoinitiator residues in polycoupled carton packaging and in contained food beverages. 相似文献
11.
An analytical method for the quantitative determination of the principal phenolic compounds (benzoic acids, hydroxycinnamic acids, 3-phenylpropionic acids, flavanols, procyanidins, dihydrochalcones, quercetin glycosides) in ciders, which successfully employs a RP-HPLC and photodiode-array detection system without prior treatment of the sample, is described. Parameters usually examined in the method validation were evaluated. Good linearity was obtained with correlation coefficients exceeding 0.999 and the detection limits ranged from 0.07 mg/L (p-hydroxybenzoic acid) to 2 mg/L (hydrocaffeic acid). Recoveries ranging between 90 and 104% and the reproducibility of the method was always < 8% (RSD). The method was applied to a set of commercial samples and the results obtained may be helpful to establish a phenolic profile in Asturian cider. 相似文献
12.
Laser induced breakdown spectroscopy (LIBS) was applied for the elemental analysis of Arabian crude oil residue samples. The spectra due to trace elements such as Ca, Fe, Mg, Cu, Zn, Na, Ni, K and Mo were recorded using this technique. The dependence of time delay and laser beam energy on the elemental spectra was also investigated. Prior to quantitative analysis, the LIBS system was calibrated using standard samples containing these trace elements. The results achieved through this method were compared with conventional technique like inductively coupled plasma. 相似文献
13.
R. M. Awadallah S. S. Ismail A. E. Mohamed 《Journal of Radioanalytical and Nuclear Chemistry》1995,196(2):377-385
The concentration of 18 elements in different cane sugar products, i.e., cane sugar plants, crude and syrup juices, molasses, and the end products of the consumer sugar, were analyzed and processed. The samples were collected from five citics, i.e., Kom Ombo, Edfu, Armant, Deshna and Naga Hammady in Upper Egypt where the main Egyptian sugar industry factories are located. INAA was applied for the determination of Al, Ca, Cl, Co, Cr, Fe, Mg, Mn, Na and Sc, while Cu, Li, P, Sn, V and Zn were determined by ICP-AES and Pb and As were determined by AAS. These three analytical methods were applied to optimize the sensitivity and the accuracy of the measurements in order to provide a sound basis for the obtention of reliable clustering results. 相似文献
14.
Iva Juranovi? Cindri? Michaela Zeiner Michaela Kröppl Gerhard Stingeder 《Microchemical Journal》2011,99(2):364-369
Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for the determination of minor and major elements present in apple juices. Prior to ICP-AES measurement, samples were diluted with nitric acid or digested in a microwave assisted digestion system. The differences in the measured element concentrations after application of different types of sample preparation procedures are discussed. The direct measurement compared to closed microwave dissolution was found to be the best sample preparation procedure. Prior to the measurements the ICP-AES method was validated and optimized for the determination of elements in apple juices. For diluted apple juice samples the lowest limits of detection (LOD) were obtained for Ba and Cd (< 20 μg L− 1), moderate ones for Cu, Mn, Ni, Fe, Ag, Ca, Cr, Zn, Mg, and Sr (20–100 μg L− 1), and the highest LODs for K, Pb, Na, and Al (> 110 μg L− 1). The results obtained for the repeatability (< 0.9%), the intermediate precision (< 4.5%), the day-to-day reproducibility (< 5.2%), and the overall uncertainty of measurement (approx. 4–7%) for all elements analyzed demonstrated the good applicability of the proposed method. Differences in major element content in fresh and commercial apple juice are discussed. 相似文献
15.
Nicoleta Simona Vedeanu Dana Alina Magdas Laura Bolojan Grigore Damian 《Chemical Papers》2012,66(6):612-616
Antioxidant status of foods, plant, or fruit products is generally characterized by means of spectroscopic methods. Methods
like HPLC, UV-VIS, or MS spectroscopy are used to understand the chemical and physical properties of different samples, and
also EPR spectroscopy seems to be a valuable tool to characterize antioxidant activity of juice beverages. In this technique,
certain antioxidants present in fruit juices interact with free radicals interrupting the chain reaction that can possibly
damage essential molecules. Recording the EPR signal decay caused by the reaction with a natural or artificial reducing agent,
it is possible to draw conclusions about the antioxidant capability of materials. IRMS is a powerful tool to distinguish between
an authentic fruit juice and a juice obtained by concentrate dilution. This technique allows also the detection of commercial
C4 cane or corn derived sugar syrups in C3 fruit juices. In the present study, four commercial fruit juices were investigated using stable isotope measurements (oxygen,
hydrogen, and carbon) and EPR measurements in order to check the correct labeling in the Romanian markets and to compare antioxidant
activity of the studied juices and the reference. It was proven that the number of paramagnetic species decreases in time
with different reaction rates and this was correlated with the antioxidant activity of the studied juices. Stable isotope
ratio measurements have demonstrated that the fruit juices studied were reconstructed from concentrates with tap water, according
to their label. 相似文献
16.
P. A. Schubiger O. Müller W. Gentner 《Journal of Radioanalytical and Nuclear Chemistry》1977,39(1-2):99-112
66 archaic Greek silver coins have been analyzed for the minor elements Cu, Au, Bi and Pb, and for the trace elements Na,
Mn, Co, Ni, As, Sn, Sb and Ir. Instrumental neutron activation has been used for the determination of Cu and Au and atomic
absorption spectroscopy for Pb and Bi. The trace elements could be detected only after a separation of the interfering matrix
activities by an extraction with a diethyl-dithio-carbamate complex. The homogeneity of Au and Cu in the coins and the significance
of the trace elements are discussed. The statistical evaluation of the analytical data reveals distinct groups for coins of
some provenances. 相似文献
17.
Yu Min Park Ji Yeon Choi Eun Yeong Nho Cheong Mi Lee In Min Hwang Naeem Khan 《Analytical letters》2019,52(6):1018-1030
This study determined the concentration of eight macroelements (Na, K, Mg, P, S, Ca, Fe, Zn) and nineteen trace elements (Li, Be, Cr, Mn, Co, Ni, V, Cu, Ga, Se, Rb, Sr, In, Sn, Cs, Ba, Tl, Bi, U) in commonly consumed canned marine products from South Korea. The samples were wet-digested using nitric acid and hydrogen peroxide by a microwave system and analyzed for macroelements using inductively coupled plasma—optical emission spectrometry (ICP-OES) and for trace elements by inductively coupled plasma—mass spectrometry (ICP-MS). The analytical methods were validated by the correlation coefficients, limits of detection and quantification, correlation variance, spiking recovery tests, and analyzing a NIST 1566?b oyster tissue certified reference material. The concentrations of macro and trace elements varied among the canned marine products. The macroelements were present in the order of Na?>?K?>?P?>?S> Mg?>?Ca?>?Fe?>?Zn. In general, the concentrations of macro and trace elements were within the specified limits of Food and Nutrition Board, Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives, and Ministry of Food and Drug Safety, Korea. The results suggest that the analyzed canned marine products are safe in terms of the analyzed elements and their consumption therefore does not cause any threat to human health. 相似文献
18.
We describe three types of automatic software for the chemometric processing of spectrometric data. The software was developed in the MATLAB working environment and includes data import, mathematical preprocessing, chemometric analysis, and generation of a report file. The software is designed to solve problems regarding identification of some components of multicomponent mixtures, determination of compounds with overlapping signals, and differentiation of samples by their spectral responses. To test the software, we present examples of spectrometric analyses of coffee, fruit juices, and alcoholic beverages using chemometric methods of independent component analysis (ICA) and partial least squares–discriminant analysis (PLS–DA). In particular, we simulated electronic absorption spectra for the identification of three artificial colors (E110, E102, and E122) in alcoholic beverages, NMR spectra for the simultaneous determination of five components (acetic acid, γ-aminobutyric acid, arginine, acetaldehyde, and proline) in orange juice without using reference standards, and NMR spectra of coffee samples to determine its varietal authenticity (Arabica or Robusta). The duration of automatic chemometric processing did not exceed 1 min per sample. The developed software can be optimized for other matrices and/or brands of spectrometers. 相似文献
19.
O. A. F. Al-Dayel S. A. Al-Kahtani 《Journal of Radioanalytical and Nuclear Chemistry》2002,252(3):605-609
Wheat is one of the most grown crops in Saudi Arabia. It is grown in various regions of the country. Accurate knowledge of the elemental concentrations in wheat and its products (bran and flour) is of great importance from a nutritional point of view. Wheat samples were obtained from the Al-Qusim region, 300 km northwest of Riyadh, and analyzed. Up to 50 elements (Al, Sb, As, Ba, Br, Cd, Ca, Cs, Cl, Cr, Co, Cu, Ga, Au, Hf, In, I, Ir, Fe, Mg, Mn, Hg, Mo, Ni, K, Rb, Sc, Se, Ag, Na, Sr, Ta, Te, Th, Sn, Ti, W, U, V, Zn, Zr, Ce, Dy, Eu, La, Lu, Nd, Sm, Tb and Yb) were determined in the wheat products. It was observed that the elemental content of bran was much higher than that of white flour. 相似文献
20.
Fernando A M Silva Carmem L Porto da Silveira Norbert Miekeley Ivo L Kuechler 《Analytical sciences》2004,20(9):1295-1299
A versatile preconcentration system for trace element determination by ICPMS was developed. It is composed of a commercial flow injection analysis system (FIAS) retrofitted with a home-made control unit containing three solenoid valves and working concomitantly with the FIAS, permitting selection and segmentation of sample, reagent, washing solution and elution flow. The knotted reactor used had a length of 200 cm and was made from 0.05 cm i.d. PTFE tubing. The method applies ammonium 1-pyrrolidinedithiocarbamate (APDC) as complexant, allowing the preconcentration and quantitative multi-element determination of Cu, Ni, V, Co, Nb, Mo, In, Sb and Bi. Ethanol and 4-methyl-2-pentanone were tested as eluents. Recovery tests using complex matrices and spike concentrations of 200 ng L(-1) showed typical values in the range of 90% to 110%. Relative standard deviations were < 7% for elution with ethanol and < 5% with methyl isobutyl ketone. For simulated freshwater samples using 4-methyl-2-pentanone as an eluent, a sample loading rate of 5.0 ml min(-1), and a preconcentration time of 60 s, detection limits (ng L(-1)) were in the range of 0.02 (Bi) to 30 (Cu). Under these conditions, analytical frequency was about 15 samples per hour. The feasibility of the method was demonstrated by the succesful analysis of wastewater and seawater certified reference materials. 相似文献