A comparison of the performance of the methodologies used in two distinct laboratories (LabA and ... more A comparison of the performance of the methodologies used in two distinct laboratories (LabA and LabB) for multi-element analysis in different wines was carried out. ICP-MS apparatus (quadrupole mass analyzers) of different brands as well as different wine pre-treatments were used. At LabA, a pre-treatment by UV-irradiation was performed. At LabB, a micro-concentric nebulizer was used for direct analysis of the wine. Twenty-six elements (Li, V, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Pb) were measured in common at the two labs in three different wine samples (red and white Bordeaux table wines and Port wine) and the results were compared. The two methodologies provided similar LODs and similar precisions, with RSDs of 0.5–5%, for most of the elements. The recovery percentages were 85–120% at LabA for the three wines, and 78–119% at LabB for the Bordeaux wines, validating the accuracy of the methods used. Comparable results were obtained at both labs for ten elements (Li, V, Co, Ni, Cu, Zn, Rb, Sr, Ba, and Pb) in the three selected wines; the differences were lower than 10% in most cases. For REEs, the differences observed were slightly higher, but still in the acceptable range due to the sub-ppb levels involved. The results obtained for As and Ga were not comparable, due to methodological influence. A comparison through linear least-squares adjustment indicated that the results obtained by the two labs were linearly correlated (correlation coefficient=0.997) but statistically different as the slope was slightly, but significantly different from one, for a confidence level of 95% (the intercept was statistically identical to zero in any case). In the future, strictly more identical results can be achieved by using a reference wine sample.
Abstract This study determined the content in 39 trace and ultratrace elements, among them 16 rar... more Abstract This study determined the content in 39 trace and ultratrace elements, among them 16 rare earth elements, in 153 wines from the Canary Islands (Spain). Analyses were performed by ICP-MS. Rare earth elements were strongly correlated among one another, ...
Directive 2000/36/EC allows chocolate makers to add up to 5% of only six specific cocoa butter eq... more Directive 2000/36/EC allows chocolate makers to add up to 5% of only six specific cocoa butter equivalents (CBEs) to cocoa butter (CB). A quantification method based on triacylglycerol (TAG) class analysis by gas chromatography with an unpolar column was set up for routine control purposes of chocolate bars. Mixtures of CBEs/CB were elaborated according to a Placket-Burman experiment design and analyzed by gas chromatography. A matrix was built with the normalized values of TAG classes (C50, C52, C54, and C56) of pure CBs of various origins, homemade CB/CBE mixtures (1 CB type), and mixtures containing CBE with CBs of various origins. A multivariate calibration equation was computed from this matrix using a partial least-squares regression technique. CBE addition can be detected at a minimum level of 2%, and the mathematical model allows its quantification with an uncertainty of 2% with respect to the cocoa butter fats. The model has also been applied for deconvolution and quantification of each CBE of a CBE mixture in chocolate bars.
Protein profiles, obtained by high-performance capillary electrophoresis (HPCE) on white wines pr... more Protein profiles, obtained by high-performance capillary electrophoresis (HPCE) on white wines previously dialyzed, combined with shikimic acid concentration and multivariate analysis, were used for the determination of grape variety composition of a still white wine. Six varieties were studied through monovarietal wines elaborated in the laboratory: Chardonnay (24 samples), Chenin , Petit Manseng , Sauvignon (37), Semillon (24), and Ugni Blanc (9). Homemade mixtures were elaborated from authentic monovarietal wines according to a Plackett-Burman sampling plan. After protein peak area normalization, a matrix was elaborated containing protein results of wines (mixtures and monovarietal). Partial least-squares processing was applied to this matrix allowing the elaboration of a model that provided a varietal quantification precision of around 20% for most of the grape varieties studied. The model was applied to commercial samples from various geographical origins, providing encouraging results for control purposes.
Despite the robustness of isotopic methods applied in the field of wine control, isotopic values ... more Despite the robustness of isotopic methods applied in the field of wine control, isotopic values can be slightly influenced by enological practices. For this reason, must concentration technique effects on wine isotopic parameters were studied. The two studied concentration techniques were reverse osmosis (RO) and high-vacuum evaporation (HVE). Samples (must and extracted water) have been collected in various French vineyards. Musts were microfermented at the laboratory, and isotope parameters were determined on the obtained wine. Deuterium and carbon-13 isotope ratios were studied on distilled ethanol by nuclear magnetic resonance (NMR) and isotope ratio mass spectrometry (IRMS), respectively. The oxygen-18 ratio was determined on extracted and wine water using IRMS apparatus. The study showed that the RO technique has a very low effect on isotopic parameters, indicating that this concentration technique does not create any isotopic fractionation, neither at sugar level nor at water level. The effect is notable for must submitted to HVE concentration: water evaporation leads to a modification of the oxygen-18 ratio of the must and, as a consequence, ethanol deuterium concentration is also modified.
Pollution of musts and wines by petroleum by-products may happen accidentally by mechanical machi... more Pollution of musts and wines by petroleum by-products may happen accidentally by mechanical machines, particularly during harvests. A new method for detecting and determining this type of pollutant, using fluorescence, has been developed in the present work. The principal pollutant investigated was diesel fuel which exhibits a characteristic fluorescence spectrum, whichever its origin. Fluorescence is principally emitted by traces of polycyclic aromatic compounds (PACs), principally polycyclic aromatic hydrocarbons (PAHs), contained in most petroleum by-products. The method involves a liquid-liquid extraction of PAHs using cyclohexane and fluorescence measurements were performed on the resulting “cyclohexane extracts.” Some natural compounds extracted from must and wine samples may also exhibit an intrinsic fluorescence emission which interferes with the characteristic fluorescence of pollutants. This is the case, in particular, of tannins contained in red wines and in wood. Thus, this prevents any reliable determination of pollutants. Natural compounds were efficiently separated from PAHs using solid phase extraction by elution of the cyclohexane solution on the florisil phase. The corresponding fluorescence was totally eliminated at the characteristic emission wavelength of pollutants. Thus, the presence of any pollution by diesel fuel could be characterized unambiguously and determined accurately. The limits of detection and quantification were determined to be around 0.3 and 1.0 μL L−1, respectively. Uncertainties on determinations were estimated at less than 20% for diesel fuel, provided a reference spectrum of the pollutant is available. If not, the pollutant concentration can be estimated within a factor two. The evolution of the pollution with time was also investigated over several weeks, particularly during the time of fermentation. The method is fairly simple to implement, quick and reliable.
One hundred and fifty-three white, rosé and red wine samples from the Canary Islands (Spain) were... more One hundred and fifty-three white, rosé and red wine samples from the Canary Islands (Spain) were analysed. The wines were sampled from two different vintages, eight denominations of origin, and four islands. The concentration of 20 trace and ultratrace elements was measured by inductively coupled plasma mass spectrometry (ICP-MS). Differences in element concentrations depending on vintage, type of wine (white, rosé, red), and region of origin were observed.
, time-of-flight (TOF) and multicollector (MC) sector-field (SF)] of ions produced in an inductiv... more , time-of-flight (TOF) and multicollector (MC) sector-field (SF)] of ions produced in an inductively coupled plasma were evaluated for the determination of lead isotope ratios in wine samples. A population of 20 wines of different origin including two reference wines from the EC Standards, Measurement and Testing Programme with concentrations varying between 7 -140 mg Pb l − 1 was investigated. Wines were analyzed directly by Q ICP MS and MC ICP MS. The poor sensitivity of the TOF instrument, further aggravated by matrix signal suppression, did not allow the acquisition of data for wine samples that contained less than 50 mg l − 1 in the direct sample introduction mode. The separation and preconcentration of lead were therefore required. The precision obtained for the 206 Pb/ 207 Pb and 208 Pb/ 206 Pb were similar and equal to 0.14-2.7% for Q ICP MS, 0.04-0.17% for TOF ICP MS and 0.01-0.12% for MC ICP MS. The precision for 206 Pb/ 204 Pb was 0.44-5.29, 0.15-1.7, 0.08-1.6%, respectively. On the level of accuracy, the data from TOF ICP MS and MC ICP MS were in good agreement. The accuracy of Q ICP MS data was judged satisfactory in comparison with the other techniques but their poor precision was a significant obstacle on the way of using these data for the determination of the geographic origin of wine.
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2003
Because of their high toxicity, arsenic, lead and cadmium need to be quantified in food and bever... more Because of their high toxicity, arsenic, lead and cadmium need to be quantified in food and beverages. For the first time, in this study the content of arsenic, lead and cadmium was investigated in 152 wine samples from the Canary Islands, Spain, belonging to eight Denominations of Origin (DO) and four islands by inductively coupled plasma mass spectrometry (ICP-MS). The ranges of concentration found were 0.58-8.45 μg l-1 for arsenic, 0.20-1.73 μg l-1 for cadmium and 3.89-159.5 μg l-1 for lead, and the mean content was 3.13, 0.63 and 28.74 μg l-1, respectively. None of the wines contained levels above the limits set by the International Office of Vine and Wine (OIV), and thus did not pose a health hazard. Significant differences in mean content of those elements between harvest, type of wine, islands and DO were observed.
... 13 02 01 Z0098. The authors thank Fiona Darbyshire and Matt Horstwood from the NERCIsotope Ge... more ... 13 02 01 Z0098. The authors thank Fiona Darbyshire and Matt Horstwood from the NERCIsotope Geosciences Laboratory (NIGL), UK, for carrying out the Sr/Rb separation. References. 1, G. Faure, Principles of Isotope Geology, Wiley, New York, 1986. . ...
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2000
Over the last century, the atmospheric fallout of anthropogenic lead has evolved with time, as a ... more Over the last century, the atmospheric fallout of anthropogenic lead has evolved with time, as a function of the chronological variability of transient lead inputs from both industrial and gasoline origins. This variability has been mostly documented over North America and northern Europe. In this study we used ICP-MS for the determination of lead isotope ratios and showed that a series of French wines followed the evolution of the environmental lead record over the last century. We observe the same three-step chronological evolution of the lead isotopic composition, which reflects a western European signal. In the post 1950 vintages, the lead isotope composition reflects a dominant atmospheric fallout. Since ˜1950, Pb concentrations have been much lower than before, decreasing consistently from ˜0.25mg l-1 around the early 1950s, down to less than ˜0.1mg l-1 nowadays. Reflecting the airborne pollution, the lead isotopic signature is also specific of the continental origin of the wines and lead isotope ratios determination in wines appears to be a promising tool for certifying wine authenticity.
A comparison of the performance of the methodologies used in two distinct laboratories (LabA and ... more A comparison of the performance of the methodologies used in two distinct laboratories (LabA and LabB) for multi-element analysis in different wines was carried out. ICP-MS apparatus (quadrupole mass analyzers) of different brands as well as different wine pre-treatments were used. At LabA, a pre-treatment by UV-irradiation was performed. At LabB, a micro-concentric nebulizer was used for direct analysis of the wine. Twenty-six elements (Li, V, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Pb) were measured in common at the two labs in three different wine samples (red and white Bordeaux table wines and Port wine) and the results were compared. The two methodologies provided similar LODs and similar precisions, with RSDs of 0.5–5%, for most of the elements. The recovery percentages were 85–120% at LabA for the three wines, and 78–119% at LabB for the Bordeaux wines, validating the accuracy of the methods used. Comparable results were obtained at both labs for ten elements (Li, V, Co, Ni, Cu, Zn, Rb, Sr, Ba, and Pb) in the three selected wines; the differences were lower than 10% in most cases. For REEs, the differences observed were slightly higher, but still in the acceptable range due to the sub-ppb levels involved. The results obtained for As and Ga were not comparable, due to methodological influence. A comparison through linear least-squares adjustment indicated that the results obtained by the two labs were linearly correlated (correlation coefficient=0.997) but statistically different as the slope was slightly, but significantly different from one, for a confidence level of 95% (the intercept was statistically identical to zero in any case). In the future, strictly more identical results can be achieved by using a reference wine sample.
Abstract This study determined the content in 39 trace and ultratrace elements, among them 16 rar... more Abstract This study determined the content in 39 trace and ultratrace elements, among them 16 rare earth elements, in 153 wines from the Canary Islands (Spain). Analyses were performed by ICP-MS. Rare earth elements were strongly correlated among one another, ...
Directive 2000/36/EC allows chocolate makers to add up to 5% of only six specific cocoa butter eq... more Directive 2000/36/EC allows chocolate makers to add up to 5% of only six specific cocoa butter equivalents (CBEs) to cocoa butter (CB). A quantification method based on triacylglycerol (TAG) class analysis by gas chromatography with an unpolar column was set up for routine control purposes of chocolate bars. Mixtures of CBEs/CB were elaborated according to a Placket-Burman experiment design and analyzed by gas chromatography. A matrix was built with the normalized values of TAG classes (C50, C52, C54, and C56) of pure CBs of various origins, homemade CB/CBE mixtures (1 CB type), and mixtures containing CBE with CBs of various origins. A multivariate calibration equation was computed from this matrix using a partial least-squares regression technique. CBE addition can be detected at a minimum level of 2%, and the mathematical model allows its quantification with an uncertainty of 2% with respect to the cocoa butter fats. The model has also been applied for deconvolution and quantification of each CBE of a CBE mixture in chocolate bars.
Protein profiles, obtained by high-performance capillary electrophoresis (HPCE) on white wines pr... more Protein profiles, obtained by high-performance capillary electrophoresis (HPCE) on white wines previously dialyzed, combined with shikimic acid concentration and multivariate analysis, were used for the determination of grape variety composition of a still white wine. Six varieties were studied through monovarietal wines elaborated in the laboratory: Chardonnay (24 samples), Chenin , Petit Manseng , Sauvignon (37), Semillon (24), and Ugni Blanc (9). Homemade mixtures were elaborated from authentic monovarietal wines according to a Plackett-Burman sampling plan. After protein peak area normalization, a matrix was elaborated containing protein results of wines (mixtures and monovarietal). Partial least-squares processing was applied to this matrix allowing the elaboration of a model that provided a varietal quantification precision of around 20% for most of the grape varieties studied. The model was applied to commercial samples from various geographical origins, providing encouraging results for control purposes.
Despite the robustness of isotopic methods applied in the field of wine control, isotopic values ... more Despite the robustness of isotopic methods applied in the field of wine control, isotopic values can be slightly influenced by enological practices. For this reason, must concentration technique effects on wine isotopic parameters were studied. The two studied concentration techniques were reverse osmosis (RO) and high-vacuum evaporation (HVE). Samples (must and extracted water) have been collected in various French vineyards. Musts were microfermented at the laboratory, and isotope parameters were determined on the obtained wine. Deuterium and carbon-13 isotope ratios were studied on distilled ethanol by nuclear magnetic resonance (NMR) and isotope ratio mass spectrometry (IRMS), respectively. The oxygen-18 ratio was determined on extracted and wine water using IRMS apparatus. The study showed that the RO technique has a very low effect on isotopic parameters, indicating that this concentration technique does not create any isotopic fractionation, neither at sugar level nor at water level. The effect is notable for must submitted to HVE concentration: water evaporation leads to a modification of the oxygen-18 ratio of the must and, as a consequence, ethanol deuterium concentration is also modified.
Pollution of musts and wines by petroleum by-products may happen accidentally by mechanical machi... more Pollution of musts and wines by petroleum by-products may happen accidentally by mechanical machines, particularly during harvests. A new method for detecting and determining this type of pollutant, using fluorescence, has been developed in the present work. The principal pollutant investigated was diesel fuel which exhibits a characteristic fluorescence spectrum, whichever its origin. Fluorescence is principally emitted by traces of polycyclic aromatic compounds (PACs), principally polycyclic aromatic hydrocarbons (PAHs), contained in most petroleum by-products. The method involves a liquid-liquid extraction of PAHs using cyclohexane and fluorescence measurements were performed on the resulting “cyclohexane extracts.” Some natural compounds extracted from must and wine samples may also exhibit an intrinsic fluorescence emission which interferes with the characteristic fluorescence of pollutants. This is the case, in particular, of tannins contained in red wines and in wood. Thus, this prevents any reliable determination of pollutants. Natural compounds were efficiently separated from PAHs using solid phase extraction by elution of the cyclohexane solution on the florisil phase. The corresponding fluorescence was totally eliminated at the characteristic emission wavelength of pollutants. Thus, the presence of any pollution by diesel fuel could be characterized unambiguously and determined accurately. The limits of detection and quantification were determined to be around 0.3 and 1.0 μL L−1, respectively. Uncertainties on determinations were estimated at less than 20% for diesel fuel, provided a reference spectrum of the pollutant is available. If not, the pollutant concentration can be estimated within a factor two. The evolution of the pollution with time was also investigated over several weeks, particularly during the time of fermentation. The method is fairly simple to implement, quick and reliable.
One hundred and fifty-three white, rosé and red wine samples from the Canary Islands (Spain) were... more One hundred and fifty-three white, rosé and red wine samples from the Canary Islands (Spain) were analysed. The wines were sampled from two different vintages, eight denominations of origin, and four islands. The concentration of 20 trace and ultratrace elements was measured by inductively coupled plasma mass spectrometry (ICP-MS). Differences in element concentrations depending on vintage, type of wine (white, rosé, red), and region of origin were observed.
, time-of-flight (TOF) and multicollector (MC) sector-field (SF)] of ions produced in an inductiv... more , time-of-flight (TOF) and multicollector (MC) sector-field (SF)] of ions produced in an inductively coupled plasma were evaluated for the determination of lead isotope ratios in wine samples. A population of 20 wines of different origin including two reference wines from the EC Standards, Measurement and Testing Programme with concentrations varying between 7 -140 mg Pb l − 1 was investigated. Wines were analyzed directly by Q ICP MS and MC ICP MS. The poor sensitivity of the TOF instrument, further aggravated by matrix signal suppression, did not allow the acquisition of data for wine samples that contained less than 50 mg l − 1 in the direct sample introduction mode. The separation and preconcentration of lead were therefore required. The precision obtained for the 206 Pb/ 207 Pb and 208 Pb/ 206 Pb were similar and equal to 0.14-2.7% for Q ICP MS, 0.04-0.17% for TOF ICP MS and 0.01-0.12% for MC ICP MS. The precision for 206 Pb/ 204 Pb was 0.44-5.29, 0.15-1.7, 0.08-1.6%, respectively. On the level of accuracy, the data from TOF ICP MS and MC ICP MS were in good agreement. The accuracy of Q ICP MS data was judged satisfactory in comparison with the other techniques but their poor precision was a significant obstacle on the way of using these data for the determination of the geographic origin of wine.
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2003
Because of their high toxicity, arsenic, lead and cadmium need to be quantified in food and bever... more Because of their high toxicity, arsenic, lead and cadmium need to be quantified in food and beverages. For the first time, in this study the content of arsenic, lead and cadmium was investigated in 152 wine samples from the Canary Islands, Spain, belonging to eight Denominations of Origin (DO) and four islands by inductively coupled plasma mass spectrometry (ICP-MS). The ranges of concentration found were 0.58-8.45 μg l-1 for arsenic, 0.20-1.73 μg l-1 for cadmium and 3.89-159.5 μg l-1 for lead, and the mean content was 3.13, 0.63 and 28.74 μg l-1, respectively. None of the wines contained levels above the limits set by the International Office of Vine and Wine (OIV), and thus did not pose a health hazard. Significant differences in mean content of those elements between harvest, type of wine, islands and DO were observed.
... 13 02 01 Z0098. The authors thank Fiona Darbyshire and Matt Horstwood from the NERCIsotope Ge... more ... 13 02 01 Z0098. The authors thank Fiona Darbyshire and Matt Horstwood from the NERCIsotope Geosciences Laboratory (NIGL), UK, for carrying out the Sr/Rb separation. References. 1, G. Faure, Principles of Isotope Geology, Wiley, New York, 1986. . ...
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2000
Over the last century, the atmospheric fallout of anthropogenic lead has evolved with time, as a ... more Over the last century, the atmospheric fallout of anthropogenic lead has evolved with time, as a function of the chronological variability of transient lead inputs from both industrial and gasoline origins. This variability has been mostly documented over North America and northern Europe. In this study we used ICP-MS for the determination of lead isotope ratios and showed that a series of French wines followed the evolution of the environmental lead record over the last century. We observe the same three-step chronological evolution of the lead isotopic composition, which reflects a western European signal. In the post 1950 vintages, the lead isotope composition reflects a dominant atmospheric fallout. Since ˜1950, Pb concentrations have been much lower than before, decreasing consistently from ˜0.25mg l-1 around the early 1950s, down to less than ˜0.1mg l-1 nowadays. Reflecting the airborne pollution, the lead isotopic signature is also specific of the continental origin of the wines and lead isotope ratios determination in wines appears to be a promising tool for certifying wine authenticity.
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