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1. |
Measurement of equilin and estrone in human plasma by capillary gas chromatography‐negative ion chemical ionization mass spectrometry |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 6-11
P. R. Robinson,
M. D. Jones,
J. Maddock,
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摘要:
AbstractA procedure is described for the analysis of the estrogens equilin and estrone in human plasma following oral administration of conjugated estrogen preparations. After enzymatic hydrolysis of the sulfate conjugates, plasma proteins are precipitated with methanol and the estrogens extracted into ethyl acetate. Derivatization with the reagent flophemesylamine converts equilin and estrone into volatile pentafluorophenyldimethylsilyl ethers ideally suited to capillary gas chromatography‐negative ion chemical ionization mass spectrometry. Using a 15 meter dimethyl silicone bonded phase fused silica capillary column separation of the estrone and equilin derivatives is achieved within 9 minutes. Selected ion monitoring of the intense negative molecular ions enables levels of 1 ng.ml−1to be measured with coefficients of variation of 9.3 % and 14.2 % for estrone and equilin respectively. Plasma levels of the compounds are reported in two male volunteers up to 24 hours after dosing with 5 milligrams of Premarin™. (™ Ayerst Laboratories Inc., New York
ISSN:0935-6304
DOI:10.1002/jhrc.1240100102
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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2. |
HPLC of anions on coated reversed phase columns using indirect UV‐detection and eluents containing nitrophthalic acids |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 12-16
D. H. Fröhlich,
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摘要:
AbstractAnalysis of anions by HPLC has been optimized in the direction of reduced analysis times with standard reversed phase columns and UV detection. This was achieved by use of a new eluent containing 3‐nitrophthalic acid and small proportions of acetonitrile. Resin‐based and silica‐based anion exchangers of varying ion‐exchange capacities are prepared with cetyltrimethylammonium bromide by a rapid dynamic coating technique. Some new, strong eluents containing nitrophthalic acids are evaluated and compared with an eluent containing potassium hydrogen phthalate. Addition of acetonitrile was found to improve the retention behavior of mono‐ and divalent anions. An automatic system was developed for the analysis of chloride, nitrate, and sulfate in drinking water. It is shown that a water sample can be analyzed in less than two minutes on a column of 25
ISSN:0935-6304
DOI:10.1002/jhrc.1240100103
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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3. |
Liquid chromatographic trace enrichment with on‐line capillary gas chromatography for the determination of organic pollutants in aqueous samples |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 17-24
E. Noroozian,
F. A. Maris,
M. W. F. Nielen,
R. W. Frei,
G. J. de Jong,
U. A. Th. Brinkman,
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摘要:
AbstractTrace enrichment for the GC analysis of a series of chlorinated pesticides and polychlorinated biphenyls (PCBs) in aqueous samples has been achieved through a simple on‐line technique involving sorption on an LC micro‐precolumn followed by direct elution into a gas chromatograph with hexane. A 5‐m retention gap coupled to the capillary GC column served as the recipient of a relatively large sample volume (ca.100 μl) introduced into the GC. Partially concurrent solvent evaporation during sample introduction allowed a large sample capacity. Recoveries of more than 95% were observed for the majority of the compounds studied. Using 1.0 ml aqueous samples, detection limits of less than 1 ppt were found. The applicability of the developed method was demonstrated for a river water
ISSN:0935-6304
DOI:10.1002/jhrc.1240100104
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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4. |
Determination of residual monomers in acrylate dispersions by gas chromatography |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 25-26
G. Stoev,
M. Angelova,
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摘要:
AbstractThe content of residual monomers is one of the most important characteristics of polymer dispersions. As a result of the similar physicochemical parameters of ethyl acrylate and methyl methacrylate, it is very difficult to determine the residual monomers in acrylate dispersions obtained by emulsion polymerization of both monomers. Gas chromatography with capillary columns, however, permits separation of these monomers and their quantitative determination in acrylate dispersions.
ISSN:0935-6304
DOI:10.1002/jhrc.1240100105
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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5. |
Microbore HPLC column performance and temperature programming capabilities |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 27-31
Harold McNair,
Jeff Bowermaster,
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摘要:
AbstractMicrobore columns (1 mm i.d.) are compared to conventional 4.6 mm i.d. columns with respect to speed, efficiency and sensitivity. If column lengths, particule diameter, packing efficiency, mobile phase, and linear velocity are the same, most chromatographic properties such as speed (analysis time), efficiency, pressure drop, and sensitivity are the same. The major differences are the column volumes, the void volumes, and the volumetric flow rates for equal linear flow velocities. The low flow rates of microbore columns (30 to 200 μl/min), conserve solvent and make for easier interfacing to other instruments such as MS, NMR, or FTIR. Temperature programming of microbore HPLC columns produces faster analyses for large k′ values, increased sensitivity (due primarily to sharper peak shape), and increases the range of compounds which can be handled in an isocratic mo
ISSN:0935-6304
DOI:10.1002/jhrc.1240100106
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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6. |
Preparation of inert glass capillary columns coated with UCON 50 HB‐5100. An attempt to rediscover industrially produced α, ω‐polyethylene/polypropyleneglycol ethers as stationary phases in capillary gas chromatography |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 32-38
W. Blum,
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摘要:
AbstractUsing UCON 50 HB‐5100, one of the most successful stationary phases in capillary gas chromatography during the past decade, as an example, we wish to redirect attention to the excellent properties of the polyethylene/polypropyleneglycol ether copolymer coatings. Based on experience gained in work with OH‐terminated polysiloxanes, a method is described for preparing inert and relatively temperature stable chemically bonded and crosslinked coatings in a single working step. Methyltrimethoxysilane was used as coupling agent, and trifluoroacetic acid was introduced as an acidic catalyst. The reaction mechanisms involved as well as the influence of additional crosslinking on the column behavior are discussed, particularly with respect of the inertness of the coati
ISSN:0935-6304
DOI:10.1002/jhrc.1240100107
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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7. |
Trace residue analysis. Chemometric estimations of sampling, amount, and error Edited by David A. Kurtz, ACS Symposium Series, Vol. 284, x + 284 pages, 1985. US $ 59.95 |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 38-38
W. Bertsch,
J. Brill,
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ISSN:0935-6304
DOI:10.1002/jhrc.1240100108
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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8. |
Adsorption phenomena of 2, 3, 7, 8‐tetrachlorodibenzodioxin and OCDF in high resolution gas chromatography |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 41-42
M. Swerev,
W. Schäfer,
K. Ballschmiter,
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ISSN:0935-6304
DOI:10.1002/jhrc.1240100109
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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9. |
Analysis of three aminonitropyrene isomers via fused silica gas chromatography combined with negative ion atmospheric pressure ionization mass spectrometry |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 43-45
W. A. Kortmacher,
L. G. Rushing,
R. J. Engelbach,
J. P. Freeman,
Z. Djurić,
E. K. Fifer,
F. A. Beland,
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ISSN:0935-6304
DOI:10.1002/jhrc.1240100110
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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10. |
Purification of plasmid by high‐performance gel filtration |
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Journal of High Resolution Chromatography,
Volume 10,
Issue 1,
1987,
Page 45-46
Y. Yamaseki,
Y. Kato,
T. Murotsu,
S. Fukushige,
K. Matsubara,
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ISSN:0935-6304
DOI:10.1002/jhrc.1240100111
出版商:Wiley Subscription Services, Inc., A Wiley Company
年代:1987
数据来源: WILEY
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