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| 1. |
IX. The Determination of Specific Nitrogen Compounds |
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C R C Critical Reviews in Analytical Chemistry,
Volume 7,
Issue 4,
1978,
Page 297-322
Stanley Jacobs,
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PDF (1726KB)
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摘要:
The determination of nitrogen in a biological sample usually involved the total nitrogen content, as in the case of proteins, mucopolysaccharides, or other compounds of biochemical interest, or the major portion of the nitrogen, which may occur in the form of α-amino nitrogen. However, it may occasionally be necessary to determine a quantity of a nitrogenous compound present in only a trace amount. It is under such conditions that a modern physical technique proves to be so valuable. In food analysis, it is very important to establish the quantity of N-nitrosamines in the cured meat or related product. Gough and Sugden45have developed a dual-column gas-chromatographic system for use in the mass-spectroscopic determinations of N-nitrosamines. They described an application of their system to the determinations of N-nitrosodi-methylamine and N-nitrosopycrolidine in cured meats and related products. Two stainless-steel columns are connected in series and operated at 140°C with helium (4 ml/min) as carrier gas. One column of dimensions 1.6 m × 1.8 mm is packed with 15% Carbowax® 20M on AW-DMCS Chromosorb W® (80 to 100 mesh), and the other column, of dimensions 30 m × 0.5 mm, is a support-coated open tubular column containing Carbowax 20M.
ISSN:0007-8980
DOI:10.1080/10408347808542703
出版商:Taylor & Francis Group
年代:1978
数据来源: Taylor
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| 2. |
The Nitrogen Detector in Gas Chromatography |
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C R C Critical Reviews in Analytical Chemistry,
Volume 7,
Issue 4,
1978,
Page 323-380
Randall C. Hall,
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PDF (2710KB)
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摘要:
The flameless alkali sensitized detector and the ECD have excellent response characteristics for the general detection of nitrogen-containing compounds. Choosing between these detectors is not a simple matter since they have both advantages and disadvantages. The FASD usually exhibits an order of magnitude of greater sensitivity than the ECD. Although it is very sensitive, it is not totally selective for nitrogen. It also responds to phosphorus, and the phosphorus response is normally about ten times greater than the nitrogen response. The response depends upon the condition of the source and may require frequent adjustments of the source temperature to minimize source aging effects. Response of this detector is dependent upon the structure of the compound and is therefore difficult to predict.
ISSN:0007-8980
DOI:10.1080/10408347808542704
出版商:Taylor & Francis Group
年代:1978
数据来源: Taylor
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