Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Adsorptive stripping voltammetric determination of dimenhydrinate at a hanging mercury drop electrode (1999)
    Springer
    Microchimica acta 130 (1999), S. 165-171 
    Details
    ISSN: 1436-5073
    Keywords: dimenhydrinate ; adsorptive stripping voltammetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Dimenhydrinate exhibits a single adsorptive stripping peak at a hanging mercury drop electrode after accumulation at 0.0V vs Ag/AgCl electrode at pH 3.8 (acetate buffer). The addition of trace amounts of copper ions enhanced the dimenhydrinate peak and its height depends on the concentration of each dimenhydrinate and Cu2+. The adsorptive stripping response was evaluated with respect to accumulation time and potential, concentration dependence, electrolyte, the presence of other purines, surfactants and other metal ions, and some variables. The calibration graph for dimenhydrinate determination is linear over the range 2.0×10−8−2.0×10−7 M (pre-concentration for 60s). The correlation factor is found to be 0.985 and RSD is 3.2% at 1.0×10−7 M. Detection limit is 1.0×10−8 M after 5 min accumulation. The determination of dimenhydrinate in pharmaceutical formulations by the proposed method is also reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01244923
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Dynamic response characteristics of an impinging-jet amperometric detector (1990)
    Weinheim : Wiley-Blackwell
    Electroanalysis 2 (1990), S. 463-469 
    Details
    ISSN: 1040-0397
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A dynamic response experiment at an impinging-jet detector indicated that laminar flow in the straight delivery tube was modified by mixing stages in the electrode channel and its connections. The response obtained, resulting from this final dispersion, defines an effective detection volume of 7 μL. In a practical flow injection line made from a number of connectors, coils, and so on, this small volume ensured that the detector described here, which incorporated a well-activated glassy carbon electrode, would not be expected to contribute significantly to the overall dispersion.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140020608
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Cathodic stripping voltammetry of D-penicillamine and N-acetylcysteine in the presence of nickel ion (1996)
    Weinheim : Wiley-Blackwell
    Electroanalysis 8 (1996), S. 40-43 
    Details
    ISSN: 1040-0397
    Keywords: D-Penicillamine ; N-Acetylcysteine ; Stripping voltammetry ; Catalytic current ; Nickel ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: D-Penicillamine (Pen) can be preconcentrated on a hanging mercury drop electrode in the presence of NiII (0.5 mM) at potentials between 0.0 and -0.4V vs. Ag/AgCl, (3 M KCl). Pen is adsorbed either as the mercury thiolate or as the NiII Pen complex. Accumulation as the nickel complex occurs at the more negative potentials in this range, i.e., near -0.4V, where mercury thiolate is not formed. When the mercury thiolate has been accumulated and mercury ion is reduced during the scan, Pen is released to form the nickel(II) complex. This overall accumulation behavior is typical of thiol compounds that form strong chelate complexes with NiII.Pen in the adsorbed state catalyzes the reduction of NiII giving a differential pulse cathodic stripping voltammetric peak at -0.6V (pH 7). Pen can be determined at concentrations down to 15 nM. N-Acetylcysteine (Ac-CysH) which has no catalytic properties for the reduction of NiII, can be determined at pH 7 in phosphate-acetate buffer, using the reduction peak of its accumulated mercury thiolate salt. The mutual interferences of Pen and Ac-CysH are negligible.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140080109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Sensitive adsorptive stripping voltammetric determination of xanthine and its derivatives (1995)
    Weinheim : Wiley-Blackwell
    Electroanalysis 7 (1995), S. 975-979 
    Details
    ISSN: 1040-0397
    Keywords: Xanthine ; Xanthine derivatives ; Adsorptive accumulation ; Stripping voltammetry ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sensitive cathodic stripping voltammetric procedures for trace determination of xanthine (I), 7-methylxanthine (II) and 1,7-dimethylxanthine (III) are reported. The methods are based on the accumulation of the copper(I) complexes of the compounds on the hanging mercury drop electrode. The adsorptive stripping response was evaluated with respect to accumulation time, potential, concentration, pH and other variables. Linear calibration graphs were obtained over the range from 2.0 × 10-8 to 2.0 × 10-9 M; the limits of detection, with accumulation times of 4 min for I and III, and of 6 min for II, were calculated to be 5.0 × l0-10 1.0 × 10-9 and 5 × 10-10 M, respectively. Possible interferences by other purine derivatives were examined. The simultaneous determination of 1.7-dimethylxanthine (paraxanthine) and theophylline is possible by the proposed method.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140071012
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Adsorptive stripping voltammetry of phenylthiohydantoin and methylthiohydantoin derivatives of amino acids in the presence of copper(II) ions at a hanging mercury drop electrode (1991)
    Weinheim : Wiley-Blackwell
    Electroanalysis 3 (1991), S. 385-391 
    Details
    ISSN: 1040-0397
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the absence of Copper(II) - and even in its presence, if accumulation has been effected at positive potentials vs. Ag/AgCl - phenylthiohydantoin and methylthiohydantoin derivatives of amino acids gave a peak at -0.60 V (pH 8.0) owing to reduction of the mercury salt formed upon accumulation. At negative accumulation potentials, the presence of copper(II) affected the adsorptive stripping voltammograms markedly, including the lowering of the detection limits. When accumulation was effected at -0.3 V, the thiohydantoin derivatives gave single peaks in the range -0.4 to -0.6 V owing to reduction of copper(II) accumulated as copper(II) complexes. Determinations could be made readily at the 5 × 10-9 M level, accumulating at -0.3 V (pH 8.0) or -0.1 V (pH 4.5): calibration plots were rectilinear up to 8 × 10-8 M. Accumulation at -0.1 V (pH 8.0) in some cases gave additional minor peaks, but glycine derivatives were exceptional in giving a well-defined peak at a considerably more negative potential. This peak appeared to be due to the accumulation of a different copper(II) complex, and evidence was obtained for the interconversion of these complexes in the surface. Mutual interferences by competitive adsorption were observed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140030423
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Signal shapes and single-boundary measurements in flow injection analysis with amperometric detection (1991)
    Weinheim : Wiley-Blackwell
    Electroanalysis 3 (1991), S. 273-280 
    Details
    ISSN: 1040-0397
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The shapes of normal and reverse flow injection (nFI and rFI) signals have been studied using single-channel manifolds, amperometric and visible spectrophotometric detection, and small and large (〉 1.5 mL) injection volumes. The shapes of nFI and rFI signals are fundamentally different because in rFI the sample, being the carrier stream, is present in essentially infinite volume. For this reason, rFI signals are broader and are prone to double-peak formation at lower injection volumes than are nFI signals. Contributions to the final signal from dispersion at the front and rear boundaries of the injected bolus frequently are, or appear to be, unequal. With loop injection, the rear boundary travels further than the front boundary and is dispersed more: injection by stream switching removes this factor. With spectrophotometric detection, correction for large and opposite refractive index effects at the two boundaries may be required. In amperometric detection, differences in acidity of carrier stream and injectate can cause significant changes in background current on switching and can distort the signal at low concentrations of monitorand. When these factors are eliminated, however, other factors causing peak height and peak shape differences remain: differences in dispersion rates of reactants, and of reaction rates, appear to be the major factors.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140030406
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...