ISSN:0935-6304    

DOI:10.1002/jhrc.1240140302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractDifferently pretreated glass capillaries were coated with hydroxy‐terminated methyl or methyl‐phenyl polysiloxane gum phases and cured at 340–360°C for several hours. The volatile reaction products formed during the baking procedure were analyzed and the retention behavior of various polar test compounds were investigated both before and after the heat treatment. The findings were used to establish a reaction scheme which explains crosslinking and surface bonding of hydroxy‐terminated silicone phases in high‐temperature‐silylated glass capillaries. The principle has been extended to the immobilization of common endcapped silicone phases by mixing them with hydroxy‐ter

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe design of an on‐line LC‐GC‐FTIR system using an on‐column interface and partially concurrent solvent evaporation with early vapor exit is described. The integration of LC‐GC coupling into vapor phase FTIR analysis enables problems of sensitivity encountered with HRGC‐FTIR detection to be over‐come. The applicability of the method is demonstrated by the identification and determination of citropten and bergapten in

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractAdditives and oligomers from polymers were quantitatively extracted and separated using on‐line SFE and capillary SFC. Conditions were found which extracted the additives selectively and separated them from the co‐extracted oligom

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractMicro‐LC and capillary zone electrophoresis (CZE) are two of the most rapidly developing, miniaturized separation techniques in analytical science. In the present paper, both techniques were comparatively evaluated for the determination of several important thiols derivatized with the fluorogenic reagent SBD‐F. Different parameters, such as selectivity, sensitivity, analysis time and efficiency, influence of column length, CZE buffer concentration, and voltage were thus analyzed and discussed. Both techniques are recommended for the analysis of thiols in biological samp

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractFused silica columns of 4.6 μm i.d. were coated with 3‐sulfopropylsilane as a cation exchanger and 3‐(2‐aminoethyl‐amino)‐propylsilane as an anion exchanger. Fast separations of cations (<25 seconds) and of anions (<35 seconds) were obtained, using a potentiometric microelectrode as a detector. In proceeding towards smaller i.d.s, a mixture of alkali metal cations could be separated successfully in an uncoated fused silica capillary of 2.3 μm i.d. as a result of retention by the surface silanol group

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractA simple method is described which enables solutes to be collected at an electrically isolated exit after they have been separated by a free solution capillary electrophoretic system. The method is illustrated by the separation of dansyl amino acids using multiple separation capillaries.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractHigh performance capillary electrophoresis using a buffer solution containing micelles of ionic surfactant (e.g.sodium dodecyl sulfate), called micellar electrokinetic chromatography, has been applied to the separation and simultaneous determination of creatinine and uric acid in human plasma and urine. The sample was introduced into the capillary by siphoning an appropriate volume of untreated plasma or urine spiked with an internal standard (antipyrine). Creatinine, uric acid, and antipyrine were separated mutually, and from other endogeneous components within 18 min. The calibration plots showed good linearity (correlation coefficient>0.999) over the concentration range needed for clinical analysis. Standard addition tests indicated that the recoveries of creatinine and uric acid from urine samples ranged, respectively, from 97 % to 106 % and 97.4 % to 108 % with a coefficient of variation (C.V.) of 3.3 % (n= 5), and that those from plasma samples ranged, respectively, from 100 % to 112 % and 101 % to 107 % with aC.V.of 4.7 % (n= 5). The results were in agreement with those obtained by conventional methods.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractAn immersed flowcell has been developed for fluorescence detection in capillary electrophoresis (CE) by modifying an ordinary HPLC spectrofluorimetric detector flowcell. The minimum detectability obtained for riboflavine was about 4 fmol. The use of the flowcell to measure a fluorescence spectrum by the stopped‐flow method of shutting down the DC high voltage during a wavelength scan, has also been achieved successfull

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe influence of temperature and capillary column stationary phase polarity on the equivalent chain length (ECL) values of unsaturated fatty acid methyl esters (FAMEs) is discussed. Comparisons are made of a bonded, nonpolar methyl silicone, bonded and nonbonded polyethylene glycols, and a highly polar, stabilized cyanosilicone stationary phase. The change in the ECL values over a 20° temperature range is used to demonstrate selectivity shifts and the influence of temperature on the separation of FAMEs on these phases. The effect of the degree of unsaturation of the FAME components, on the various stationary phases is also investigated

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140311

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY