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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 364 (1999), S. 533-540 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Solid sampling graphite furnace atomic absorption spectroscopy (SS-GFAAS) has been used for the determination of traces of heavy metals (Cd, Pb, Cu, Cr, Ni, V and As) in barytes over a wide concentration range, e.g. Cd from 0.023 to 27.0 μg/g and Pb from 1.54 to 3509 μg/g.The necessity of determining heavy metals in commercial barytes (naturally occurring barium sulfate), a mineral important to the oil industry because of its use in drilling muds, is discussed. The problems presented by the analysis of this difficult matrix are elegantly solved by using SS-GFAAS for the direct determination of heavy metals. A high-performance graphite furnace AAS with D2-background correction system and a transversely heated graphite atomizer was used for the investigations. The spectrometer was combined with a mechanical sampling module and an ultramicrobalance. The transfer of solid samples (sample weights 0.031–0.686 mg) into the atomizer was carried out by using an optimized graphite platform as the sample carrier. Calibration curve techniques and standard addition methods were employed using external standards (CRMs). Problems associated with signal deformations like multiple peaks, tailing or shoulders are also discussed and possibilities to solve the problems are given. The influence of the homogeneity of solid samples on the precision and accuracy are shown in a real example. The results obtained by SS-GFAAS were compared with results by other methods like X-ray fluorescence spectroscopy (XRF) and flame AAS after aqua regia microwave extraction. This study has demonstrated that SS-GFAAS is a very powerful and easy-to-use method for quick and accurate analysis of barytes.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 351 (1995), S. 320-324 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Samples of marine sediments collected in the vicinity of and remote from an oil production platform have been analysed for several metals (Cr, Cu, Fe, Mn, Ni, and Pb) and for total hydrocarbons. The same samples have been examined by diffuse reflectance IR spectroscopy (DRIFT) after drying, and an attempt has been made to classify the samples according to the patterns of the metals and the reflectance spectra, and to correlate this classification with that based on the sampling site. It is suggested that DRIFT is a faster technique than the conventional solvent-extraction IR method for total hydrocarbons and — while less sensitive — is adequate for screening such samples for significant levels of hydrocarbon pollution. Classification of the samples according to the metals present also distinguishes between the two groups of samples.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 43 (1996), S. 205-207 
    ISSN: 1612-1112
    Keywords: Gas-solid chromatography ; Chromosorb 101 ; Anaesthetic gas mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Gas chromatography has been employed in the separation of mixtures of air, carbon dioxide, nitrous oxide and a volatile anaesthetic (halothane, isoflurane or enflurane) on a single Chromosorb 101 column by temperature programming from room temperature. Calibration over the required range for the analysis of exhaled air, demonstrated good linearity with a repeatability for test mixtures of about 1%.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1612-1112
    Keywords: Gas-solid chromatography ; Dual column system ; Thermal conductivity detector ; Anaesthetic gas mixture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A dual column gas-solid chromatography is described for the separation and quantitative analysis of anaesthetic gas mixtures of halothane (isoflurane or enflurane), nitrous oxide, air and carbon dioxide. The separation was performed on two Chromosorb 101 columns (2m and 2m+2m). The second column was placed outside the oven and operated at room temperature.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 351 (1995), S. 625-628 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The luminescent bacterium Photobacterium phosphoreum has been used to examine samples of oily drilling cuttings from the sea bottom in the vicinity of a North Sea oil production platform. Because the presence of any fine particulate matter results in a depression of the bioluminescence, the cuttings must first be extracted and the extract filtered before mixing with the bacterial suspension. A sea-water extract of a low toxicity drilling oil gave a small but significant depression of bioluminescence, but extracts with 1% v/v ethanol or DMSO gave a 50% greater depression. Samples of cuttings from different depths (representing different ages, up to 15 years) showed a different pattern, with similar effects from the aqueous and the mixed-solvent extracts. It is assumed that the toxic component therefore is not originating from the drilling mud oil, but from some additive which has a rather higher solubility in water than the hydrocarbons.
    Type of Medium: Electronic Resource
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