... Separation and Pulsed Amperometric Detection of Alditols and Carbohydrates by Anion-Exchange ... more ... Separation and Pulsed Amperometric Detection of Alditols and Carbohydrates by Anion-Exchange Chromatography Using Alkaline Mobile Phases Modified withBa(II), Sr(II), and Ca(II) Ions. ... Ba(II)-Containing Alkaline Eluents. ...
Journal of electroanalytical chemistry and interfacial electrochemistry, Sep 1, 1990
Abstract The successful expansion which the scanning tunneling microscopy (STM) has had is depend... more Abstract The successful expansion which the scanning tunneling microscopy (STM) has had is dependent on its ability to examine surfaces on a sub-nanometric scale and on providing in situ (i.e. in the presence of bulk electrolyte) sample examination. In addition to the ability to study metals and semiconductors in vacuo, the application of the technique to surfaces in contact with an electrolytic solution has prompted increased interest amongst electrochemists. We discuss herein the technique, with particular reference to advances in electrochemical applications. A new scanning tunneling microscope for operation in electrolytic environments is described. Atomic force microscopy, scanning electrochemical microscopy and scanning ion-conducting microscopy are compared with the STM.
Early diagnosis of neural changes causing cerebral impairment is critical for proposing preventiv... more Early diagnosis of neural changes causing cerebral impairment is critical for proposing preventive therapies for Parkinson’s disease (PD). Biomarkers currently available cannot be informative of PD onset since they are characterized by analysing post-mortem tissues from patients with severe degeneration of the substantia nigra. Skin fibroblasts (SF) are now recognized as a useful model of primary human cells, capable of reflecting the chronological and biological aging of the subjects. Here a lipidomic study of easily accessible primary SF is presented, based on hydrophilic interaction liquid chromatography coupled to electrospray ionization and mass spectrometry (HILIC/ESI-MS). Phospholipids (PL) from dermal fibroblasts of five PD patients with different parkin mutations and healthy control SF were characterized by single and tandem MS measurements using a hybrid quadrupole-Orbitrap and a linear ion trap mass analysers. The proposed approach enabled the identification of more than ...
Scopatizzo, belonging to the Cucumis melo L., is a local variety of Apulia (Southern Italy), whic... more Scopatizzo, belonging to the Cucumis melo L., is a local variety of Apulia (Southern Italy), which is consumed as unripe melon as an alternative of cucumber due to its better-quality profile and for the absence of cucurbitacins. The latter are tetracyclic triterpenes synthesized by some Cucurbitaceae species, known to confer an unpleasant taste to fruits and cause health problems. Following the discovery of Scopatizzo fruits with bitter taste, cucurbitacins were searched for in their ethanolic extract. Flow injection analysis with detection performed by atmospheric pressure chemical ionization-high resolution mass spectrometry provided evidence for the presence of at least four cucurbitacins, which were absent in typical, sweet-tasting fruits. Further insight into this discovery will be required in the near future to assess if the detection of cucurbitacins may mark the appearance of genotypes whose fruits have features not compatible with commercialization.
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is largely recognized ... more Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is largely recognized as an important tool in the analysis of many biomolecules such as proteins and peptides. The MS analysis of digested peptides to identify a protein or some of its modifications is a key step in proteomics. MALDI-MS is well suited for the peptide mass fingerprinting (PMF) technique, as well as selected fragmentation of various precursors using collisional-induced dissociation (CID) or post-source decay (PSD).In the last few years, MALDI-MS has played a significant role in food chemistry, especially in the detection of food adulterations, characterization of food allergens, and investigation of protein structural modifications induced by various industrial processes that could be an issue in terms of food quality and safety.Here, we present simple extraction protocols of allergenic proteins in food commodities such as milk, egg, hazelnut , and lupin seeds. Classic bottom-up approaches based on Sodium Dodecyl Sulphate (SDS) gel electrophoresis separation followed by in-gel digestion or direct in-solution digestion of whole samples are described. MALDI-MS and MS /MS analyses are discussed along with a comparison of data obtained by using the most widespread matrices for proteomic studies, namely, α-cyano-4-hydroxy-cinnamic acid (CHCA) and α-cyano-4-chloro-cinnamic acid (CClCA). The choice of the most suitable MALDI matrix is fundamental for high-throughput screening of putative food allergens.
Journal of Electroanalytical Chemistry, May 1, 1998
An electrochemically deposited indium(III)-hexacyanoferrate (InHCF) film on glassy carbon and pla... more An electrochemically deposited indium(III)-hexacyanoferrate (InHCF) film on glassy carbon and platinum electrodes has been investigated by X-ray photoelectron spectroscopy (XPS). Attempts were made to characterise such a polynuclear inorganic film upon its electrochemical conditioning in both reduced and oxidised forms. The indium ions were unaffected by the oxidation state of the film and were present mainly as In(III). In the
Journal of the American Society for Mass Spectrometry, Mar 11, 2021
In the past decade, hydrophilic interaction liquid chromatography (HILIC) has emerged as an effic... more In the past decade, hydrophilic interaction liquid chromatography (HILIC) has emerged as an efficient alternative to reversed-phase chromatography (RPC) for the analysis of phospholipid (PL) mixtures based on mass spectrometric detection. Since the separation of PL by HILIC is chiefly based on their headgroup, the mass spectrum of each class can be obtained by spectral averaging under the corresponding HILIC band. Using experimental m/z values resulting from high mass resolution/accuracy instruments, the sum compositions of PL in a specific class can be thus inferred but partial overlapping may occur between signals related to the M + 0 isotopologue of one species and the M + 2/M + 4 isotopologues of species having one/two more C═C bonds in their chemical structures. Here, an automated workflow, named LIPIC (lipid isotopic pattern interference correction), is proposed to account for such interferences. Starting from the experimentally verified assumption that peaks in isotope patterns are Gaussian, LIPIC predicts, as a function of m/z ratio, signal intensities due to M + 2 and M + 4 isotopologues of species with one or two more C = C bonds than the target one and calculates the corrected intensity for the M + 0 isotopologue of the latter. Thanks to an iterative procedure, the suggested algorithm compensates also for slight shifts occurring between experimental and theoretical m/z ratios related to isotopologue peaks. Examples of applications to simulated and experimental mass spectra of two PL classes, i.e., phosphatidylcholines (PC) and cardiolipins (CL), emphasize the increased extent of correction at the increase of molecular masses of involved species.
... Separation and Pulsed Amperometric Detection of Alditols and Carbohydrates by Anion-Exchange ... more ... Separation and Pulsed Amperometric Detection of Alditols and Carbohydrates by Anion-Exchange Chromatography Using Alkaline Mobile Phases Modified withBa(II), Sr(II), and Ca(II) Ions. ... Ba(II)-Containing Alkaline Eluents. ...
Journal of electroanalytical chemistry and interfacial electrochemistry, Sep 1, 1990
Abstract The successful expansion which the scanning tunneling microscopy (STM) has had is depend... more Abstract The successful expansion which the scanning tunneling microscopy (STM) has had is dependent on its ability to examine surfaces on a sub-nanometric scale and on providing in situ (i.e. in the presence of bulk electrolyte) sample examination. In addition to the ability to study metals and semiconductors in vacuo, the application of the technique to surfaces in contact with an electrolytic solution has prompted increased interest amongst electrochemists. We discuss herein the technique, with particular reference to advances in electrochemical applications. A new scanning tunneling microscope for operation in electrolytic environments is described. Atomic force microscopy, scanning electrochemical microscopy and scanning ion-conducting microscopy are compared with the STM.
Early diagnosis of neural changes causing cerebral impairment is critical for proposing preventiv... more Early diagnosis of neural changes causing cerebral impairment is critical for proposing preventive therapies for Parkinson’s disease (PD). Biomarkers currently available cannot be informative of PD onset since they are characterized by analysing post-mortem tissues from patients with severe degeneration of the substantia nigra. Skin fibroblasts (SF) are now recognized as a useful model of primary human cells, capable of reflecting the chronological and biological aging of the subjects. Here a lipidomic study of easily accessible primary SF is presented, based on hydrophilic interaction liquid chromatography coupled to electrospray ionization and mass spectrometry (HILIC/ESI-MS). Phospholipids (PL) from dermal fibroblasts of five PD patients with different parkin mutations and healthy control SF were characterized by single and tandem MS measurements using a hybrid quadrupole-Orbitrap and a linear ion trap mass analysers. The proposed approach enabled the identification of more than ...
Scopatizzo, belonging to the Cucumis melo L., is a local variety of Apulia (Southern Italy), whic... more Scopatizzo, belonging to the Cucumis melo L., is a local variety of Apulia (Southern Italy), which is consumed as unripe melon as an alternative of cucumber due to its better-quality profile and for the absence of cucurbitacins. The latter are tetracyclic triterpenes synthesized by some Cucurbitaceae species, known to confer an unpleasant taste to fruits and cause health problems. Following the discovery of Scopatizzo fruits with bitter taste, cucurbitacins were searched for in their ethanolic extract. Flow injection analysis with detection performed by atmospheric pressure chemical ionization-high resolution mass spectrometry provided evidence for the presence of at least four cucurbitacins, which were absent in typical, sweet-tasting fruits. Further insight into this discovery will be required in the near future to assess if the detection of cucurbitacins may mark the appearance of genotypes whose fruits have features not compatible with commercialization.
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is largely recognized ... more Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is largely recognized as an important tool in the analysis of many biomolecules such as proteins and peptides. The MS analysis of digested peptides to identify a protein or some of its modifications is a key step in proteomics. MALDI-MS is well suited for the peptide mass fingerprinting (PMF) technique, as well as selected fragmentation of various precursors using collisional-induced dissociation (CID) or post-source decay (PSD).In the last few years, MALDI-MS has played a significant role in food chemistry, especially in the detection of food adulterations, characterization of food allergens, and investigation of protein structural modifications induced by various industrial processes that could be an issue in terms of food quality and safety.Here, we present simple extraction protocols of allergenic proteins in food commodities such as milk, egg, hazelnut , and lupin seeds. Classic bottom-up approaches based on Sodium Dodecyl Sulphate (SDS) gel electrophoresis separation followed by in-gel digestion or direct in-solution digestion of whole samples are described. MALDI-MS and MS /MS analyses are discussed along with a comparison of data obtained by using the most widespread matrices for proteomic studies, namely, α-cyano-4-hydroxy-cinnamic acid (CHCA) and α-cyano-4-chloro-cinnamic acid (CClCA). The choice of the most suitable MALDI matrix is fundamental for high-throughput screening of putative food allergens.
Journal of Electroanalytical Chemistry, May 1, 1998
An electrochemically deposited indium(III)-hexacyanoferrate (InHCF) film on glassy carbon and pla... more An electrochemically deposited indium(III)-hexacyanoferrate (InHCF) film on glassy carbon and platinum electrodes has been investigated by X-ray photoelectron spectroscopy (XPS). Attempts were made to characterise such a polynuclear inorganic film upon its electrochemical conditioning in both reduced and oxidised forms. The indium ions were unaffected by the oxidation state of the film and were present mainly as In(III). In the
Journal of the American Society for Mass Spectrometry, Mar 11, 2021
In the past decade, hydrophilic interaction liquid chromatography (HILIC) has emerged as an effic... more In the past decade, hydrophilic interaction liquid chromatography (HILIC) has emerged as an efficient alternative to reversed-phase chromatography (RPC) for the analysis of phospholipid (PL) mixtures based on mass spectrometric detection. Since the separation of PL by HILIC is chiefly based on their headgroup, the mass spectrum of each class can be obtained by spectral averaging under the corresponding HILIC band. Using experimental m/z values resulting from high mass resolution/accuracy instruments, the sum compositions of PL in a specific class can be thus inferred but partial overlapping may occur between signals related to the M + 0 isotopologue of one species and the M + 2/M + 4 isotopologues of species having one/two more C═C bonds in their chemical structures. Here, an automated workflow, named LIPIC (lipid isotopic pattern interference correction), is proposed to account for such interferences. Starting from the experimentally verified assumption that peaks in isotope patterns are Gaussian, LIPIC predicts, as a function of m/z ratio, signal intensities due to M + 2 and M + 4 isotopologues of species with one or two more C = C bonds than the target one and calculates the corrected intensity for the M + 0 isotopologue of the latter. Thanks to an iterative procedure, the suggested algorithm compensates also for slight shifts occurring between experimental and theoretical m/z ratios related to isotopologue peaks. Examples of applications to simulated and experimental mass spectra of two PL classes, i.e., phosphatidylcholines (PC) and cardiolipins (CL), emphasize the increased extent of correction at the increase of molecular masses of involved species.
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Papers by Tommaso Cataldi