Papers by Maria Bruzzoniti
Analytica Chimica Acta, 2007
Acta Chimica Slovenica
ABSTRACT
Journal of Chromatography A, 2012
(AAM) is copyrighted and published by Elsevier. It is posted here by agreement between Elsevier a... more (AAM) is copyrighted and published by Elsevier. It is posted here by agreement between Elsevier and the University of Turin. Changes resulting from the publishing process-such as editing, corrections, structural formatting, and other quality control mechanisms-may not be reflected in this version of the text. The definitive version of the text was subsequently published in [insert name of publication, volume number, issue number, date, and digital object identifier link]. You may download, copy and otherwise use the AAM for non-commercial purposes provided that your license is limited by the following restrictions: (1) You may use this AAM for non-commercial purposes only under the terms of the CC-BY-NC-ND license. (2) The integrity of the work and identification of the author, copyright owner, and publisher must be preserved in any copy.
Journal of Chromatography a, Aug 3, 2001
The chromatographic behavior of carboxylic acids has been investigated, on three different latex-... more The chromatographic behavior of carboxylic acids has been investigated, on three different latex-based anion-exchange columns, in order to define the effect of the ion-exchange site structure on selectivity. The analytical columns produced are characterized by alkyl amines containing zero, one or two hydroxyl groups on the anion-exchange functional site. Divalent carboxylic acids, namely fumaric, maleic, trans-b-hydromuconic, trans,trans-muconic, oxalic, malonic, succinic, glutaric, adipic, malic, tartaric and mucic acids, have been chosen as test solutes. The performance of the three stationary phases has been studied employing NaOH eluents and has been discussed with respect to the different hydrophilicity of the ion-exchange sites and analytes. Considering on previous results obtained using organic solvents (methanol and acetonitrile) with carbonate eluents on a highly hydrophilic column, the performance of the three exchangers has also been studied using acetonitrile, methanol and n-propanol. The chromatographic behavior was similar for the three columns studied, but the different organic solvents gave variations in selectivity. In order to characterize these differences, particle size measurements of the latices were performed both in pure water and in the presence of each organic solvent studied.
Chromatographia, 2002
Summary The optimization of chromatographic methods for the determination of metal species requi... more Summary The optimization of chromatographic methods for the determination of metal species require an understanding of the mechanisms involved. In this work, the separation of Cd, Co, Cu, Fe(II/III), Mn, Pb and Zn using a mixed bed column (IonPac CS5A) and a cation-exchange column (IonPac CS2) is studied as a function of mobile phase composition. The type and concentration of complexing
Chromatographic Science Series, 2010
Analytical and Bioanalytical Chemistry, 2014
Seven quick, easy, cheap, effective, rugged and safe (QuEChERS)-based procedures, differing in bo... more Seven quick, easy, cheap, effective, rugged and safe (QuEChERS)-based procedures, differing in both the extraction and clean-up steps, were investigated for the recovery of bentazone (BTZ), atrazine (ATZ), carbamazepine (CBZ), phenytoin (PNT) and its metabolite 5-(p-hydroxyphenyl-),5-phenylhydantoin (HPPH) from soil. Target analytes were chosen for their extensive use and/or occurrence in soil, as well as for their medium-high polarity characteristics (log K OW values in the range 0.88-2.80), which have been reported as a critical parameter for the recovery from soil with QuEChERS approaches. Liquid chromatography coupled with UV and pulsed amperometric (PA) detection at a glassy carbon electrode was used as instrumental technique. The recovery data obtained within each tested procedure were discussed for each compound investigated, highlighting different behaviour depending on the specific physicochemical characteristics of the analytes. The optimized QuEChERS conditions consisted of the extraction of analytes with CH3CN:H2O 70:30, 5 % CH3COOH, followed by a dispersive solid-phase extraction (d-SPE) clean-up step with C18 sorbent. This method, in which water is directly added to the soil together with acetonitrile and salts, allowed the rehydration step to be avoided, which can be as long as 30 min. Matrix effects were evaluated for both the detection techniques at different concentration levels, and they were below 24 % for both the detection technique used. The recoveries were evaluated at three concentration levels by a matrix-matched calibration and were in the ranges of 83-113 % (relative standard deviations (RSD) ≤ 14 %) and 88-109 % (RSD ≤ 11 %) for UV and PA detection, respectively, highlighting very good performances of the method, even for the more polar analytes. Method detection limits ranged from 4 μg/kg (BTZ) to 493 μg/kg (PNT) and from 4 μg/kg (HPPH) to 11 μg/kg (BTZ) for UV and PA detection, respectively. The method was finally compared with a microwave-assisted extraction procedure which provided less satisfactory extraction performances than the optimized QuEChERS procedure.
Analytical and Bioanalytical Chemistry, 2014
Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) is an extraction and clean-up techniqu... more Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) is an extraction and clean-up technique originally developed for recovering pesticide residues from fruits and vegetables. Since its introduction, and until December 2013, about 700 papers have been published using the QuEChERS technique, according to a literature overview carried out using SciFinder, Elsevier SciVerse, and Google search engines. Most of these papers were dedicated to pesticide multiresidue analysis in food matrices, and this topic has been thoroughly reviewed over recent years. The QuEChERS approach is now rapidly developing beyond its original field of application to analytes other than pesticides, and matrices other than food, such as biological fluids and non-edible plants, including Chinese medicinal plants. Recently, the QuEChERS concept has spread to environmental applications by analyzing not only pesticides but also other compounds of environmental concern in soil, sediments, and water. To the best of our knowledge, QuEChERS environmental applications have not been reviewed so far; therefore, in this contribution, after a general discussion on the evolution and changes of the original QuEChERS method, a critical survey of the literature regarding environmental applications of conventional and modified QuEChERS methodology is provided. The overall recoveries obtained with QuEChERS and other extraction approaches (e.g., accelerated solvent extraction, ultrasonic solvent extraction, liquid/solid extraction, and soxhlet extraction) were compared, providing evidence for QuEChERS higher recoveries for various classes of compounds, such as biopesticides, chloroalkanes, phenols, and perfluoroalkyl substances. The role of physicochemical properties of soil (i.e., clay and organic carbon content, as well as cation exchange capacity) and target analytes (i.e., log KOW, water solubility, and vapor pressure) were also evaluated in order to interpret recovery and matrix effect data.
Journal of Separation Science, 2007
Retention of heavy metal ions on SBA-15 mesoporous silica functionalised with carboxylic groups T... more Retention of heavy metal ions on SBA-15 mesoporous silica functionalised with carboxylic groups Three samples of SBA-15 functionalised with -(CH 2 ) 3 COOH groups have been prepared by co-condensation, starting from solutions of TEOS and 4-(triethoxysilyl)butyronitrile, acting as -(CH 2 ) 3 COOH precursor, of different molar compositions. Materials were characterised by X-ray diffraction, nitrogen adsorption, and FT-IR spectroscopy. The pK a and the acidic capacity were measured for all samples by potentiometric titration. The acidic capacity increases with increasing amount of -COOH precursor in the synthesis mixture only up to 10% molar of total alkoxysilane. The value for the pK a (4.75) is independent of the acidic capacity of the material. The sample prepared starting from an amount of -COOH precursor equal to 10% molar of total alkoxysilane was chosen to test selective interactions with heavy metals of environmental importance (Ag + , Cd 2+ , Fe 3+ , Cu 2+ , Zn 2+ ) at different pH values and ionic strengths. The significant and selective adsorption exhibited by the material has been exploited in a preliminary cation-exchange chromatographic application showing the possibility of eluting the metal ions at different retention times.
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2007
In this study, a new aqueous insoluble ionic b-cyclodextrin polymer (PYR), synthesized by reactio... more In this study, a new aqueous insoluble ionic b-cyclodextrin polymer (PYR), synthesized by reaction of b-cyclodextrin with pyromellitic anhydride [1], is characterized by IR spectroscopy, showing typical cyclodextrin and carboxylic absorptions. pH-metric titrations of the acidic functions with standard NaOH solutions followed by a refinement of protonation constants, with specific software for equilibrium in solution, have been performed. Through this approach, the pK a values of the functional groups have been calculated. The complexation capabilities of PYR towards metal ions [Al(III),
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2007
A new aqueous insoluble ionic b-cyclodextrin polymer (PYR) has been synthesized and a potentiomet... more A new aqueous insoluble ionic b-cyclodextrin polymer (PYR) has been synthesized and a potentiometric study of the binary Cu(II)-PYR system is performed to calculate the complexation constants (as logb in heterogeneous medium). The mathematical processing of the pH-metric data gave the formation constants of Cu(II) complexes and the related species distributions. The model is compatible with the presence of five complex species in the range of pH 2.5-7. Stoichiometry indicates the probable involvement of the alcoholate functionalities of the ligand in the complexation. The capacity of the polymer with respect to metal ions retention is evaluated for both Cu(II) and Cd(II) (chosen as target probes). The possibility to recover the sorbed Cd(II) is also tested by using acidic pH solutions. A complete recovery is obtained and the stability of the polymer is verified over ten steps of retention and desorption. To understand the complexation mechanism involved, two other cyclodextrin-based polymers are synthesized which are characterized by the presence of naphthalic dicarboxylic and carbonate groups as spacers. Their interactions with Cu(II) or Cd(II) are studied. Since the b-cyclodextrin polycarbonate polymer does not have acidic groups on the spacer, it is interesting to compare metal ions retention between this material, which does not present a real cation exchange site, and PYR.
Journal of Chromatography A, 1996
A theoretical model for -1 and -2 charged analytes in ion-interaction chromatography was studied ... more A theoretical model for -1 and -2 charged analytes in ion-interaction chromatography was studied and a general equation was developed for describing the simultaneous effect on the concentrations of the ion-interaction reagent, organic modifier and counter ion on k'. The modelling concerns the retention process as a result of several adsorption and ion-exchange equilibria, considering the adsorption of neutral and charged ion pairs on the stationary phase. The retention model was applied to a large number of experimental chromatographic data obtained in the separation of metal complexes on a silica C8 column. The experimental design was planned in order to describe the chromatographic behaviour in a multi-dimensional space (k' versus tetrabutylammonium, nitrate and methanol concentrations). The adsorption and ion-exchange constants were calculated by an iterative method of non-linear regression. The average error between the calculated and experimental k' values (<13%) is close to the experimental error (about 5%), supporting the applicability of the equation developed.
Journal of Chromatography A, 2004
This work is an upgrade of a previously developed method [J. Chromatogr. A 884 (2000) 251] for ep... more This work is an upgrade of a previously developed method [J. Chromatogr. A 884 (2000) 251] for epichlorohydrin determination by ion chromatography (IC) and conductivity detection. Here, an ion chromatography-mass spectrometry (IC-MS) coupling has been employed for the separation and the identification of products of epichlorohydrin when reacted with the nucleophilic agent SO 3 2− . The high capacity column (IonPac AS11-HC) used for separation provided good resolution. This allowed evaluation of the IC behavior and mass spectrometric identification of epichlorohydrin sulfite derivatives. By using atmospheric pressure interfaces (ESI and APCI) the following species were tentatively identified: 2,3-dihydroxy-1-propanesulfonic, 2,3-epoxy-1-propanesulfonic, 1,3-dihydroxy-2-propanesulfonic and 3-oxetanesulfonic acids and 2-hydroxy-1,3-propanedisulfonic acid (or its isomer 3-hydroxy-1,2-propanedisulfonic acid). The study showed that chlorine atoms are displaced from epichlorohydrin during the reaction, while mass spectrometry confirmed that none of the products formed contains chlorine atoms.
Journal of Chromatography A, 2008
A new high performance ion chromatographic method has been developed for the separation of the ni... more A new high performance ion chromatographic method has been developed for the separation of the nine chlorinated-brominated haloacetic acids (HAAs) that are the disinfection by-products of chlorination of drinking water, using a macrocycle-based adjustable-capacity anion-exchange separator column (IonPac Cryptand A1). A gradient method based on theoretical and experimental considerations has been optimized in which 10 mM NaOH-LiOH step gradient was performed at the third minute of the analysis. The optimized method allowed us to separate the nine HAAs and seven possibly interfering inorganic anions in less than 25 min with acceptable resolution. The minimum concentrations detectable for HAAs were between 8.0 (MBA) and 210 (TBA) g L −1 , with linearity included between 0.9947 (TBA) and 0.9998 (MBA). To increase sensitivity, a 25-fold preconcentration step on a reversed phase substrate (LiChrolut EN) has been coupled. Application of this method to the analysis of haloacetic acids in real tap water samples is illustrated.
Journal of Chromatography A, 1996
... Online preconcentration and separation of neutral and charged aromatic compounds by ion inter... more ... Online preconcentration and separation of neutral and charged aromatic compounds by ion interaction chromatography Corrado Sarzanini*, Maria ... compounds; Benzene; Naphthalene; Sulfonic acids, aromatic 1. Introduction Aromatic sulphonic acids derived from ben zene and ...
Journal of Chromatography A, 2001
Liquid chromatographic methods, based on reversed-phase (RP) and anion-exchange mechanisms, have ... more Liquid chromatographic methods, based on reversed-phase (RP) and anion-exchange mechanisms, have been developed for chloral hydrate determination. Both methods are preceeded by derivatization of chloral hydrate. For RP separations, different reagents [namely dansylhydrazine and o-(4-nitrobenzyl)hydroxylamine] have been studied, but the best results have been achieved using 1,2-benzenedithiol with UV detection at 220 nm. The anion-exchange method is based on derivatization with NaOH to form sodium formate that is then analyzed by anion-exchange, with suppressed conductivity detection. Derivatization conditions were optimized in order to reach the best yield of reaction. The optimization of the procedure allowed to determine chloral hydrate with detection limits as low as 0.2 mg / l with good linearity and reproducibility. The anion-exchange method was also applied for chloral hydrate determination in a drinking water sample. A preconcentration procedure has also been studied.
Journal of Chromatography A, 2009
The retention properties of a SBA-15 mesoporous silica functionalized with -(CH 2 ) 3 COOH groups... more The retention properties of a SBA-15 mesoporous silica functionalized with -(CH 2 ) 3 COOH groups, synthesized by a co-condensation route, were investigated for the ion chromatography of different cationic species. A systematic study on the effect of different eluent compositions containing non-complexing (methanesulfonic acid) or complexing (oxalic or pyridine-2,6-dicarboxylic acids) eluents, in the presence of organic modifiers (CH 3 CN, CH 3 OH, CH 3 NH 2 ) on the retention of cations (Li + , Na + , K + , Ca 2+ , Mg 2+ , Sr 2+ , Ba 2+ , NH 4 + , Cu 2+ , Ni 2+ , Zn 2+ , Cd 2+ , Co 2+ , Pb 2+ , Fe 3+ ) chosen as model analytes and for their environmental importance, allowed us to elucidate the mechanisms (cation-exchange or complexation) involved in the retention on the SBA-15 phase. For the first time separations of cations on SBA-15 based stationary phases are investigated, providing the basis for further development of mesoporous silica chemistry for in-flow ion-exchange applications.
Journal of Chromatography A, 1997
An ion-interaction method for the simultaneous separation and UV detection of compounds with weak... more An ion-interaction method for the simultaneous separation and UV detection of compounds with weak or strong ionic groups, using a divalent cationic ion pair reagent, namely hexamethonium bromide, has been studied and developed. The analytes considered were tartaric, fumaric, pyruvic, maleic, phthalic, benzoic, sorbic, 4-hydroxybenzoic, benzene and toluene-4-sulphonic acids, and they were chosen for their practical importance. The chromatographic optimization for their separation has been achieved by varying eluent composition (methanol, NaC1 and hexamethonium concentrations) and studying the performance of different stationary phases (octyl-and octadecyl-silica based columns). The method developed has been successfully applied to benzoate and sorbate determination in orange juices.
Food Additives and Contaminants, 2002
Metals in wine occur at the mg l 1 level or less and, though not directly related to the taste of... more Metals in wine occur at the mg l 1 level or less and, though not directly related to the taste of the ®nal product, their content should be determined because excess is undesirable , and in some cases prohibited, due to potential toxicity. Lead content in wine, for example, is restricted in several states by legislation to guarantee consumer health protection. Of several methods for metal determination, techniques of atomic spectroscopy are the most sensitive and rapid. Most of the elements present in wine can be determined with these techniques, at concentrations ranging from the mg l 1 to the ·g l 1 level. Here, inductively coupled plasma-atomic emission spectrometry (ICP-AES),¯ame atomic absorption spectrometry (¯ame-AAS) and graphite furnace-atomic absorption spectrometry (GF-AAS) are compared for their characteristics as employed in metal determination in wine.
Chromatographia, 2002
Summary Mesoporous silica-based materials have been synthesized and studied for applications in ... more Summary Mesoporous silica-based materials have been synthesized and studied for applications in the environmental field. Haloacetic acids have been chosen as test compounds since they are byproducts of disinfection processes of water for human consumption. For this purpose mesoporous materials have been synthesized in acid, basic or neutral conditions. The effect of composition and synthesis conditions of mesoporous materials on their
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Papers by Maria Bruzzoniti