ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Column liquid chromatography  (54)
  • Springer  (54)
  • 1995-1999  (51)
  • 1980-1984  (3)
Collection
Publisher
  • Springer  (54)
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 44 (1997), S. 257-262 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Microchromatography ; Raman spectroscopy ; Deuterated solvents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A detector for microchromatography in which Raman spectroscopy is used to identify the eluted species has been developed. The detector is designed to be applicable to a wide range of compounds without requiring the presence of a chromophore. Its use is illustrated in the analysis of nitro compounds on a 250 μm i.d. column. Raman spectra of each of the compounds could be identified as they passed the detector. The advatages of the use of fully deuterated solvents are demonstrated by the analysis of nitrobenzenes in methanol/water mobile phases. The detection limit for nitrobenzene using the Raman line at 1342 cm−1 was 75ng.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Pharmaceutical formulations ; Triprolidine ; Pseudoephedrine ; Paracetamol ; Dextromethorphan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A simple, rapid and specific HPLC method has been developed for the determination of triprolidine, pseudoephedrine, paracetamol and dextromethorphan, in combination, in different pharmaceutical dosage forms, using a reversed-phase C18 column, gradient elution, and UV detection at 254 and 280 nm. No preliminary extraction procedure is required for liquid formulations and a very simple extraction procedure is required for tablets and creams. The recovery of the drugs ranged from 96.0 to 98.7%. The assay results obtained for eight commercially available formulations were in agreement with the amounts declared. The linearity and precision of the method have been assessed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Porous graphitic carbon ; Optimization ; Morphine and metabolites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The chromatographic behaviour of a series of morphine-based opiates has been investigated using a porous graphitic carbon packing material at acid and alkaline pH. The effects of mobile phase pH, mobile phase organic percentage, column temperature and ionpairing agents were studied. All six opiates were separated within a close retention window despite large differences in measured lipophilicities of the individual opiates. The retention order was not related to the log P values of the opiates and strong retention of the fully ionised compounds was observed, particularly those with acidic functional groups. The effect of pH on the retention of the compounds indicated that the degree of ionisation of the individual compounds was important in the separation mechanism, suggesting that hydrophobic interactions were present in addition to the polar retentive effects observed above. The strong retention of the ionised glucuronide and sulphate conjugates of morphine is a particularly useful feature of the porous graphitic carbon packing material which has general applicability to the analysis of polar or ionised drug metabolites.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Gas chromatography ; Enantiomeric separation ; Chiral derivatization ; Unusual secondary aromatic amino acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary High-performance liquid chromatographic and gas chromatographic methods were developed for the separation of unusual secondary aromatic amino acids. Amino acids containing 1,2,3,4-tetrahydroisoquinoline, 1,2,3,4-tetrahydronorharmane-1-carboxylic acid and 1,2,3,4-tetrahydro-3-carboxy-2-carboline moieties were synthetized in racemic or chiral forms. The high-performance liquid chromatography was carried out either on a teicoplanin-containing chiral stationary phase or on an achiral C18 column. In the latter case the diastereomers of the amino acids formed by precolumn derivatization with the chiral reagents 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate or 1-fluoro-2,4-dinitrophenyl-5-L-alanine amide were separated. The gas chromatographic analyses were based on separation on a Chirasil-L-Val column.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; NMR spectroscopy and mass spectrometry ; Plant products ; Silene otites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary HPLC coupled in parallel to nuclear magnetic resonance (NMR) and mass spectrometry (MS) has been used to obtain1H NMR and mass spectra of a number of ecdysteroids present in an extract of the plantSilene otites. Reversed phase gradient chromatography was performed using a D20-acetonitrile-based solvent system. NMR and mass spectra were obtained for integristerone A, 20-hydroxyecdysone, 2-deoxy-20-hydroxyecdysone and 2-deoxyecdysone to provide structural confirmation using continuous and stopped flow HPLC-NMR. The combined HPLC-NMR-MS system described here provided a more comprehensive analysis of the ecdysteroids present in the extract than HPLC-NMR alone.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Solid phase extraction ; Enzyme-based biosensor detection ; Tyrosinase ; Phenols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A fully integrated screening system for phenolic compounds was developed incorporating on-line solid phase extraction, fractionation and biosensor detection. Two different types of biosensors, solid graphite and carbon paste electrodes incorporating the enzyme tyrosinase, were compared and used in the screening system. Interfacing of the solid phase extraction and fractionation with the biosensor detection was given special attention since the biosensors were not compatible with the organic modifier used for desorption of phenols from the solid phase extraction step. The system was validated with conventional analytical techniques. Surface water samples from the Ebro river were spiked with 1,10, and 25μg L−1 of catechol, phenol,p-cresol, respectively. Three out of seven samples were spiked and the correct samples were identified, containing phenols equivalent to the spiked concentrations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 44 (1997), S. 619-622 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Boldine in pharmaceuticals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is proposed for extraction, separation, identification and quantitative measurement of boldine (I) in pharmaceuticals. The extraction of (I) from the matrix (syrups, tablets, extracts) was realized with aqueous ammonium chloride (0.02 M, pH=3.0 with perchloric acid) and the clean-up of the extract was performed by solid-phase extraction by means of cartridges containing a strong cation-exchange sorbent, from which (I) was eluted with aqueous ammonium chloride (1 M, pH=10.0 with ammonia). The final eluate was examined by HPLC. Chromatography was performed on a C-8 column with a gradient elution from 15:85 to 30:70 of acetonitrile-water containing 0.1 M sodium perchlorate (pH=3.0), in 20 min. A diode array detector was used at 302 nm for detection. The method gives recovery values greater than 98% and the reproducibility is within 6.0%.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 43 (1996), S. 76-78 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Rhodamine B in cosmetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is proposed for the extraction, separation, identification and quantitative measurement of rhodamine B in cosmetics samples The colour is extracted with a solution of orthophosphoric acid in either water or DMF (depending on the type of cosmetic) adsorbed on a polyamide column, and then eluted with water and methanol. Further clean-up of the extract is performed by means of a Bond Elut C-18 cartridge, from which rhodamine B is eluted with methanol-water (8∶2). The final eluate is examined by HPLC. Chromatography is performed on a C-18 column with a gradient elution from 50∶50 to 70∶30 of acetonitrile-water, containing 0.1 M sodium perchlorate, in 15 min. A diodearray detector enables peak purity analysis. The method gives recovery values of approximately 90%, or better, and the reproducibility is within 4%.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 40 (1995), S. 237-246 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Mixed mode stationary phases ; Indirect photometric and fluorometric detection ; Conductimetric detection ; Alkyl-sulphates, and sulphonat-phosphates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Separation of three classes of anionic surfactants (alkyl sulfates, alkanesulfonates, and alkyl phosphates) are achieved on a mixed-mode reversed phase (RP) phenyl/-anion exchange column using a naphthalenetrisulfonate (NTS)-acetonitrile (ACN) mobile phase via indirect photometric, indirect fluorometric, direct or indirect conductivity detection. Mixtures of C5−C18 sulfates, C6−C18 sulfonates, and C1−C4 phosphates (mono- and di-ester) can be separated in less than 20, 24, and 20 min respectively. Although hydrophobic effects are more pronounced in mixed-mode chromatography, equivalent-per-equivalent exchange of analysis and eluent ion is still required for sensitive indirect photometric, fluorometric, or conductivity detection. The detection limits of alkyl sulfates and alkanesulfonates are in the range of 3–15 pmoles which are at least an order of magnitude better than suppressed conductivity detection. The determination of surfactants in a variety of real samples is also presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Substituted benzenes ; Solubility parameter ; Substituent constant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A quantitative structure-retention model derived from the concept of hydrophobic substituent constant (π) and the total solubility parameter (δT) has been established. It has been used to predict successfully the retention behavior of a number of solutes on various columns in several different eluents. The experimental results indicate that the model can be employed for the prediction of retention of substituted benzenes in a large volume fraction range of mobile phase. In addition, the physical meaning of the sign and the influence of the coefficients of the model on the retention process had been discussed together with the dependence of these coefficients on the composition of mobile phase.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...