Designed to serve as the first point of reference on the subject, "Comprehensive Chemometric... more Designed to serve as the first point of reference on the subject, "Comprehensive Chemometrics" presents an integrated summary of the present state of chemical and biochemical data analysis and manipulation. The work covers all major areas ranging from statistics to data acquisition, analysis, and applications. This major reference work provides broad-ranging, validated summaries of the major topics in chemometrics - with chapter introductions and advanced reviews for each area.The level of material is appropriate for graduate students as well as active researchers seeking a ready reference on obtaining and analyzing scientific data. This book features the contributions of leading experts from 21 countries, under the guidance of the Editors-in-Chief and a team of specialist Section Editors: L. Buydens; D. Coomans; P. Van Espen; A. De Juan; J.H. Kalivas; B.K. Lavine; R. Leardi; R. Phan-Tan-Luu; L.A. Sarabia; and J.Trygg. It examines the merits and limitations of each techniq...
Changes on an organism by the exposure to environmental stressors may be characterized by hypersp... more Changes on an organism by the exposure to environmental stressors may be characterized by hyperspectral images (HSI), which preserve the morphology of biological samples, and suitable chemometric tools. The approach proposed allows assessing and interpreting the effect of contaminant exposure on heterogeneous biological samples monitored by HSI at specific tissue levels. In this work, the model example used consists of the study of the effect of the exposure of chlorpyrifos-oxon on zebra fish tissues. To assess this effect, unmixing of the biological sample images followed by tissue-specific classification models based on the unmixed spectral signatures is proposed. Unmixing and classification are performed by Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and Partial Least Squares-Discriminant Analysis (PLS-DA), respectively. Crucial aspects of the approach are: a) the simultaneous MCR-ALS analysis of all images from one population to take into account biological...
ABSTRACT A new method for the water source apportionment of the Barcelona (Spain) water distribut... more ABSTRACT A new method for the water source apportionment of the Barcelona (Spain) water distribution system is proposed. The method is based on the combined use of UV spectrophotometric measurements in the wavelength from 190–230 nm, and multivariate data analysis using the Partial Least Squares (PLS) chemometric method. From the differences in the organic matter content of the different water sources and of their corresponding UV spectral features, PLS was able to determine the relative amounts of the two main river water sources in samples of tap water from the different locations of the Barcelona city water distribution system. The extension of the method to determine the relative amounts in water blends, prepared from samples from five water treatment plant sources of the same city’s distribution system, required the combined use of some other parameters. In particular, the distinction and apportion of the water coming from a desalinisation plant could be successfully achieved once concentrations of Boron were included in the analysis.
The application of multivariate curve resolution-alternating least squares (MCR-ALS) to the quant... more The application of multivariate curve resolution-alternating least squares (MCR-ALS) to the quantitative analysis of different metal ion mixtures using voltammetric data is described. The performance of MCR-ALS was evaluated in the resolution and quantitation of overlapped voltammetric peaks obtained in the analysis of binary and quaternary mixtures of Cd(II), In(III), Pb(II) and Tl(I) metal ions by anodic stripping voltammetry. Quality assessment of qualitative and quantitative determinations was evaluated considering the effects of different constraints and of initial estimations. MCR-ALS results were validated and compared with those obtained by applying other well-established multivariate calibration methods, such as partial least squares (PLS) and direct classical least squares (DCLS) methods.
This work is focused on the study of the photodegradation of 2-bromophenol under the action of UV... more This work is focused on the study of the photodegradation of 2-bromophenol under the action of UV light and sunlight. The photodegradation process has been monitored using UV-Vis spectroscopy and High Performance Liquid Chromatography coupled to diode array and mass spectrometry detectors in tandem (HPLC-DAD-MS). Multivariate resolution methods, such as Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and hybrid soft- and hard-modeling-Multivariate Curve Resolution (HS-MCR), have been applied to the experimental data to obtain the information about the kinetic evolution and identification of the compounds involved in the photodegradation process. From the analysis of HPLC-DAD results, the complexity of the photodegradation process has been confirmed. Ten components were found to be involved in parallel, second- or higher-order reactions, which could not be ascertained from the spectroscopic results. The HPLC-MS results allowed postulating the identity of some of the compounds (such as hydroxyderivatives and bromophenol homologs) which resulted from the reactions of photohydrolysis, debromination and bromine transfer to different position of the phenol ring. The effect of the UV light and sunlight on the photodegradation process was found to affect mainly the rate of the reaction, but not the identity of the photoproducts formed. The advantages and limitations of the spectroscopic and chromatographic analysis were also discussed. The potential of combining spectroscopic and chromatographic data in a single multiset structure was also shown. This strategy, uses the advantage of the good definition of the process time axis from the spectroscopic experiment and the capability to distinguish among compounds, linked to the use of chromatographic information.
Chemometrics and Intelligent Laboratory Systems, 1992
Tauler, R. and Casassas, E., 1992. Spectroscopic resolution of macromolecular complexes using fac... more Tauler, R. and Casassas, E., 1992. Spectroscopic resolution of macromolecular complexes using factor analysis: Cu(II)-polyethyleneimine system. Chemometrics and Intelligent Laboratory Systems, 14: 305-317. The complexes of Cu(II) ion with polyethyleneimine formed during a VIS spectroscopic titration of solutions containing different amounts of Cu(II) and polyethyleneimine at various pH values have been studied using a new self-resolving approach based on different factor analysis techniques, including evolving factor analysis, error in factor analysis, cross-validation, target factor analysis, and rank annihilation. Three different macromolecular complex species between Cu(II) and polyethyleneimine were detected in the system, and their concentration profiles and individual spectra were estimated without any previous knowledge of the underlying chemical model (set of stoichiometric coefficients and set of stability constants). The method developed is proposed for use in the deduction of the metal complexing properties of macromolecular systems.
We report an investigation of how much protein structural information could be obtained using a s... more We report an investigation of how much protein structural information could be obtained using a site-directed fluorescence labeling (SDFL) strategy. In our experiments, we used 21 consecutive singlecysteine substitution mutants in T4 lysozyme (residues T115-K135), located in a helix-turn-helix motif. The mutants were labeled with the fluorescent probe monobromobimane and subjected to an array of fluorescence measurements. Thermal stability measurements show that introduction of the label is substantially perturbing only when it is located at buried residue sites. At buried sites (solvent surface accessibility of <40 Å 2 ), the destabilizations are between 3 and 5.5 kcal/mol, whereas at more exposed sites, ∆∆G values of e1.5 kcal/mol are obtained. Of all the fluorescence parameters that were explored (excitation λ max , emission λ max , fluorescence lifetime, quantum yield, and steady-state anisotropy), the emission λ max and the steady-state anisotropy values most accurately reflect the solvent surface accessibility at each site as calculated from the crystal structure of cysteine-less T4 lysozyme. The parameters we identify allow the classification of each site as buried, partially buried, or exposed. We find that the variations in these parameters as a function of residue number reflect the sequence-specific secondary structure, the determination of which is a key step for modeling a protein of unknown structure.
Lecture 2 Lecture 2 R l ti f t d t • Resolution of two-way data. • Resolution conditions. -Select... more Lecture 2 Lecture 2 R l ti f t d t • Resolution of two-way data. • Resolution conditions. -Selective and pure variables. -Local rank N t l t i t -Natural constraints. • Non-iterative and iterative resolution methods d l ith and algorithms. • Multivariate Curve Resolution using Alternating L t S MCR ALS Least Squares, MCR-ALS. • Examples of application. Bilinearity!
Etude de la formation. Evaluation des constantes de stabilite. Les ethanolamines agissent comme c... more Etude de la formation. Evaluation des constantes de stabilite. Les ethanolamines agissent comme coordinats multidentes par les groupes amino et OH
Mixed ligand complexation between Cu(ll) ion, salicylate ion (sal) and a nitrogen base which acts... more Mixed ligand complexation between Cu(ll) ion, salicylate ion (sal) and a nitrogen base which acts as unidentate ligand, pyridine (py) or ammonia, is studied potentiometrically at 25 °C and in 1.0 mole dm -3 ionic media (KN0 3 or NH 4 N0 3 respectively). Experimental data are analysed using both Miniquad and Letagrop programs ; the performances of these programs are compared. Analysis of variance in the case of copper-ammonia complexation is performed. All the species present in solution in both systems are identified and their formation constants are evaluated. Distribution plots of the mixed complexes at several concentration ratios of their constituents are obtained. Stabilization of these mixed-ligand complexes. Cu(sal)(py) 2 and Cu(sal)(NH 3 ) 2 , is estimated and different stabilizing factors are discussed.
s book of Stratfeed Symposium, 16 – 18 June 2004, Namur Belgium P.41.Validation of the determinat... more s book of Stratfeed Symposium, 16 – 18 June 2004, Namur Belgium P.41.Validation of the determination of meat and bone meal in feedingstuff with NIR spectroscopy S. Termes, J. Bosch, R. Tauler, A. Puigdomenech Laboratori Agroalimetari. Departament d’Agricultura, Ramaderia i Pesca (DARP), Generalitat de Catalunya. Ctra. Vilassar a Cabrils, s/n. Cabrils, Barcelona. Spain (stermesb@gencat.net) Idem (jaume.bosch@gencat.net) Department of Environmental Chemistry Institute of Chemistry and Environmental Research, CSIC. Jordi Girona, 18-26, Barcelona. SPAIN. (rtaqam@iiqab.csic.es) Departament d’Universitats, Recerca i Societat de la Informacio (DURSI). Gabinet Tecnic de Recerca. Generalitat de Catalunya. Via Laietana 33, Barcelona. SPAIN (aapuica@gencat.net) Determination of Meat and Bone Meal in feedingstufs is an important topic since their presence has been related with mad cow decease. Several Regulations and Commission Directives have been adapted to avoid the presence of Meat and Bone Meal in feedingstufs and to establish standard methods of analysis. In 2003 the Commission Directive 2003/126/EC of 23 December 2003 established classical microscopy as the preferred method of analysis. The main inconvenience of microscopy method is that it needs long time of analysis. In this context, NIR spectrometry has been recently proposed as a fast screening method, to reduce analysis time and to reduce the number of samples to be analysed by microscopy. NIR equations developed in the calibration step must be validated before they can be used in routine analysis of feedingstuff. In this work, NIR equations are validated with a group of samples prepared in the laboratory. Values obtained using the proposed NIR spectrometric methods are compared and validated with known ‘true’ values and with those obtained using microscopy.
Thermal-induced unfolding of α-chymotrypsin has been monitored with circular dichroism spectrosco... more Thermal-induced unfolding of α-chymotrypsin has been monitored with circular dichroism spectroscopy, which shows a far-UV-CD region sensitive to changes in the protein secondary structure and a near-UV-CD region, which gives information at the tertiary structure level. Changes in CD signals in both the far-UV and the near-UV are used to monitor comprehensively the loss of protein structure during unfolding.The application
Designed to serve as the first point of reference on the subject, "Comprehensive Chemometric... more Designed to serve as the first point of reference on the subject, "Comprehensive Chemometrics" presents an integrated summary of the present state of chemical and biochemical data analysis and manipulation. The work covers all major areas ranging from statistics to data acquisition, analysis, and applications. This major reference work provides broad-ranging, validated summaries of the major topics in chemometrics - with chapter introductions and advanced reviews for each area.The level of material is appropriate for graduate students as well as active researchers seeking a ready reference on obtaining and analyzing scientific data. This book features the contributions of leading experts from 21 countries, under the guidance of the Editors-in-Chief and a team of specialist Section Editors: L. Buydens; D. Coomans; P. Van Espen; A. De Juan; J.H. Kalivas; B.K. Lavine; R. Leardi; R. Phan-Tan-Luu; L.A. Sarabia; and J.Trygg. It examines the merits and limitations of each techniq...
Changes on an organism by the exposure to environmental stressors may be characterized by hypersp... more Changes on an organism by the exposure to environmental stressors may be characterized by hyperspectral images (HSI), which preserve the morphology of biological samples, and suitable chemometric tools. The approach proposed allows assessing and interpreting the effect of contaminant exposure on heterogeneous biological samples monitored by HSI at specific tissue levels. In this work, the model example used consists of the study of the effect of the exposure of chlorpyrifos-oxon on zebra fish tissues. To assess this effect, unmixing of the biological sample images followed by tissue-specific classification models based on the unmixed spectral signatures is proposed. Unmixing and classification are performed by Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and Partial Least Squares-Discriminant Analysis (PLS-DA), respectively. Crucial aspects of the approach are: a) the simultaneous MCR-ALS analysis of all images from one population to take into account biological...
ABSTRACT A new method for the water source apportionment of the Barcelona (Spain) water distribut... more ABSTRACT A new method for the water source apportionment of the Barcelona (Spain) water distribution system is proposed. The method is based on the combined use of UV spectrophotometric measurements in the wavelength from 190–230 nm, and multivariate data analysis using the Partial Least Squares (PLS) chemometric method. From the differences in the organic matter content of the different water sources and of their corresponding UV spectral features, PLS was able to determine the relative amounts of the two main river water sources in samples of tap water from the different locations of the Barcelona city water distribution system. The extension of the method to determine the relative amounts in water blends, prepared from samples from five water treatment plant sources of the same city’s distribution system, required the combined use of some other parameters. In particular, the distinction and apportion of the water coming from a desalinisation plant could be successfully achieved once concentrations of Boron were included in the analysis.
The application of multivariate curve resolution-alternating least squares (MCR-ALS) to the quant... more The application of multivariate curve resolution-alternating least squares (MCR-ALS) to the quantitative analysis of different metal ion mixtures using voltammetric data is described. The performance of MCR-ALS was evaluated in the resolution and quantitation of overlapped voltammetric peaks obtained in the analysis of binary and quaternary mixtures of Cd(II), In(III), Pb(II) and Tl(I) metal ions by anodic stripping voltammetry. Quality assessment of qualitative and quantitative determinations was evaluated considering the effects of different constraints and of initial estimations. MCR-ALS results were validated and compared with those obtained by applying other well-established multivariate calibration methods, such as partial least squares (PLS) and direct classical least squares (DCLS) methods.
This work is focused on the study of the photodegradation of 2-bromophenol under the action of UV... more This work is focused on the study of the photodegradation of 2-bromophenol under the action of UV light and sunlight. The photodegradation process has been monitored using UV-Vis spectroscopy and High Performance Liquid Chromatography coupled to diode array and mass spectrometry detectors in tandem (HPLC-DAD-MS). Multivariate resolution methods, such as Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and hybrid soft- and hard-modeling-Multivariate Curve Resolution (HS-MCR), have been applied to the experimental data to obtain the information about the kinetic evolution and identification of the compounds involved in the photodegradation process. From the analysis of HPLC-DAD results, the complexity of the photodegradation process has been confirmed. Ten components were found to be involved in parallel, second- or higher-order reactions, which could not be ascertained from the spectroscopic results. The HPLC-MS results allowed postulating the identity of some of the compounds (such as hydroxyderivatives and bromophenol homologs) which resulted from the reactions of photohydrolysis, debromination and bromine transfer to different position of the phenol ring. The effect of the UV light and sunlight on the photodegradation process was found to affect mainly the rate of the reaction, but not the identity of the photoproducts formed. The advantages and limitations of the spectroscopic and chromatographic analysis were also discussed. The potential of combining spectroscopic and chromatographic data in a single multiset structure was also shown. This strategy, uses the advantage of the good definition of the process time axis from the spectroscopic experiment and the capability to distinguish among compounds, linked to the use of chromatographic information.
Chemometrics and Intelligent Laboratory Systems, 1992
Tauler, R. and Casassas, E., 1992. Spectroscopic resolution of macromolecular complexes using fac... more Tauler, R. and Casassas, E., 1992. Spectroscopic resolution of macromolecular complexes using factor analysis: Cu(II)-polyethyleneimine system. Chemometrics and Intelligent Laboratory Systems, 14: 305-317. The complexes of Cu(II) ion with polyethyleneimine formed during a VIS spectroscopic titration of solutions containing different amounts of Cu(II) and polyethyleneimine at various pH values have been studied using a new self-resolving approach based on different factor analysis techniques, including evolving factor analysis, error in factor analysis, cross-validation, target factor analysis, and rank annihilation. Three different macromolecular complex species between Cu(II) and polyethyleneimine were detected in the system, and their concentration profiles and individual spectra were estimated without any previous knowledge of the underlying chemical model (set of stoichiometric coefficients and set of stability constants). The method developed is proposed for use in the deduction of the metal complexing properties of macromolecular systems.
We report an investigation of how much protein structural information could be obtained using a s... more We report an investigation of how much protein structural information could be obtained using a site-directed fluorescence labeling (SDFL) strategy. In our experiments, we used 21 consecutive singlecysteine substitution mutants in T4 lysozyme (residues T115-K135), located in a helix-turn-helix motif. The mutants were labeled with the fluorescent probe monobromobimane and subjected to an array of fluorescence measurements. Thermal stability measurements show that introduction of the label is substantially perturbing only when it is located at buried residue sites. At buried sites (solvent surface accessibility of <40 Å 2 ), the destabilizations are between 3 and 5.5 kcal/mol, whereas at more exposed sites, ∆∆G values of e1.5 kcal/mol are obtained. Of all the fluorescence parameters that were explored (excitation λ max , emission λ max , fluorescence lifetime, quantum yield, and steady-state anisotropy), the emission λ max and the steady-state anisotropy values most accurately reflect the solvent surface accessibility at each site as calculated from the crystal structure of cysteine-less T4 lysozyme. The parameters we identify allow the classification of each site as buried, partially buried, or exposed. We find that the variations in these parameters as a function of residue number reflect the sequence-specific secondary structure, the determination of which is a key step for modeling a protein of unknown structure.
Lecture 2 Lecture 2 R l ti f t d t • Resolution of two-way data. • Resolution conditions. -Select... more Lecture 2 Lecture 2 R l ti f t d t • Resolution of two-way data. • Resolution conditions. -Selective and pure variables. -Local rank N t l t i t -Natural constraints. • Non-iterative and iterative resolution methods d l ith and algorithms. • Multivariate Curve Resolution using Alternating L t S MCR ALS Least Squares, MCR-ALS. • Examples of application. Bilinearity!
Etude de la formation. Evaluation des constantes de stabilite. Les ethanolamines agissent comme c... more Etude de la formation. Evaluation des constantes de stabilite. Les ethanolamines agissent comme coordinats multidentes par les groupes amino et OH
Mixed ligand complexation between Cu(ll) ion, salicylate ion (sal) and a nitrogen base which acts... more Mixed ligand complexation between Cu(ll) ion, salicylate ion (sal) and a nitrogen base which acts as unidentate ligand, pyridine (py) or ammonia, is studied potentiometrically at 25 °C and in 1.0 mole dm -3 ionic media (KN0 3 or NH 4 N0 3 respectively). Experimental data are analysed using both Miniquad and Letagrop programs ; the performances of these programs are compared. Analysis of variance in the case of copper-ammonia complexation is performed. All the species present in solution in both systems are identified and their formation constants are evaluated. Distribution plots of the mixed complexes at several concentration ratios of their constituents are obtained. Stabilization of these mixed-ligand complexes. Cu(sal)(py) 2 and Cu(sal)(NH 3 ) 2 , is estimated and different stabilizing factors are discussed.
s book of Stratfeed Symposium, 16 – 18 June 2004, Namur Belgium P.41.Validation of the determinat... more s book of Stratfeed Symposium, 16 – 18 June 2004, Namur Belgium P.41.Validation of the determination of meat and bone meal in feedingstuff with NIR spectroscopy S. Termes, J. Bosch, R. Tauler, A. Puigdomenech Laboratori Agroalimetari. Departament d’Agricultura, Ramaderia i Pesca (DARP), Generalitat de Catalunya. Ctra. Vilassar a Cabrils, s/n. Cabrils, Barcelona. Spain (stermesb@gencat.net) Idem (jaume.bosch@gencat.net) Department of Environmental Chemistry Institute of Chemistry and Environmental Research, CSIC. Jordi Girona, 18-26, Barcelona. SPAIN. (rtaqam@iiqab.csic.es) Departament d’Universitats, Recerca i Societat de la Informacio (DURSI). Gabinet Tecnic de Recerca. Generalitat de Catalunya. Via Laietana 33, Barcelona. SPAIN (aapuica@gencat.net) Determination of Meat and Bone Meal in feedingstufs is an important topic since their presence has been related with mad cow decease. Several Regulations and Commission Directives have been adapted to avoid the presence of Meat and Bone Meal in feedingstufs and to establish standard methods of analysis. In 2003 the Commission Directive 2003/126/EC of 23 December 2003 established classical microscopy as the preferred method of analysis. The main inconvenience of microscopy method is that it needs long time of analysis. In this context, NIR spectrometry has been recently proposed as a fast screening method, to reduce analysis time and to reduce the number of samples to be analysed by microscopy. NIR equations developed in the calibration step must be validated before they can be used in routine analysis of feedingstuff. In this work, NIR equations are validated with a group of samples prepared in the laboratory. Values obtained using the proposed NIR spectrometric methods are compared and validated with known ‘true’ values and with those obtained using microscopy.
Thermal-induced unfolding of α-chymotrypsin has been monitored with circular dichroism spectrosco... more Thermal-induced unfolding of α-chymotrypsin has been monitored with circular dichroism spectroscopy, which shows a far-UV-CD region sensitive to changes in the protein secondary structure and a near-UV-CD region, which gives information at the tertiary structure level. Changes in CD signals in both the far-UV and the near-UV are used to monitor comprehensively the loss of protein structure during unfolding.The application
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