ISSN:0935-6304    

DOI:10.1002/jhrc.1240020602

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

年代:1979

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020603

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

年代:1979

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020604

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

年代:1979

数据来源: WILEY

摘要:

AbstractHead space GC using a special electropneumatic sampling system works well in combination with glass capillaries. Because a homogenous gas mixture is already present most problems inherent with inlet splitters are thus avoided. In cases where the high vapor pressure of the sample can cause problems with the pressure controlled sampling system, the use of narrow bore glass capillaries provides the necessary inlet pressure. The use of this powerful and convenient analytical tool for water pollution analysis, flavour analysis and the analysis of volatiles in crude oil samples is shown by examples.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020606

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

年代:1979

数据来源: WILEY

摘要:

AbstractMost of the common classes of organic compounds chromatograph normally on Superoxes. There is no tailing or adverse effect from excessively different activity different activity coefficients. Superoxes are therefore universal phases for gas chromatography. This is also expressed by a wide useful temperature range from ∼50° to ∼300°. High MW Superox‐4 has a MAOT about 20° higher than the lower MW Superox‐0.1. Several applications illustrating the versatility of Superox phases in (GC)2are

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020607

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe proposed combination of a rather simple procedure for sample preparation with capillary gas‐liquid chromatography using a barium carbonate/polyethyleneglycol 20,000 column and a Grob‐type on‐column injector permits measurement of bile acids in serum with high separation efficiency, short analysis time and complete separation of bile acids from cholesterol. The method can be adapted to combined capillary gas‐liquid chromatography ‐ mass spe

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020608

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

年代:1979

数据来源: WILEY

摘要:

AbstractA new method for the preparation of wall‐coated glass capillary columns after surface roughening by means of amorphous silica is described. After the glass capillary has been leached, a small quantity of amorphous silica is deposited evenly on the inner surface. This is done by passing a plug of dilute water glass through the capillary, followed by a flow of gaseous hydrochloric acid. The roughened surface is stabilized, deactivated and finally coated.This paper furnishes details of the technique and information about the performance of a number of columns prepared by the metho

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020609

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe preparation of (glass) capillary columns of high quality is still not without difficulties. Six problems in this context are highlighted. Column material choice(l), glass wall modification(2) and coating(3) are considered to have reached a satisfactory level. Deactivation(4) is still in a state of flux. Quantitation(5) is the least satisfactory aspect of capillary GC. Scope expansion(6) will be helped by the introduction of new phases of high thermal stability and by the adoption of solutions exclusively applicable to capillary GC.Evaluation of (glass) capillary GC columns is a rapidly developing field. Hopefully the number and complexity of test or polarity mixtures will not expand much further and it will be possible to make a clear and generally acceptable choice.The preparation and evaluation of ever‐improving capillary columns is important to an ever‐widening group of chromatographers. Our opinion on selected topics in this already vast field is summarized in the following overv

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020610

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

年代:1979

数据来源: WILEY

摘要:

AbstractSubnanogram detection of steroids has become increasingly important today. One applicable method for gas chromatographic determination of subnanogram quantities of estrogens as halogenated derivatives is electron capture detection. HFB‐derivatives of 7 different estrogens were automatically injected onto a prolonged narrow bore wall‐coated glass capillary column. Normal split injection could not be used for this trace analysis because of too much loss of sample. Only small amounts of sample were available from which double analysis had to be performed.Cross‐contamination of the automatic sampling system as well as precision of retention times and peak areas were determined.The type of injection described showed better quantitative results compared to the splitless injection technique.All details of the system used together with the results are this discussed in this

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020611

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe technique of programming the carrier gas flow rate in gas chromatography, especially in connection with the use of capillary columns shorter than 10 m can significantly accelerate GC analyses. Equations for calculation of the parameters of the exponential flow function and retention data are described. The effects of flow programming in a short capillary column are shown in a few chromatograms. Different programming rates are tested and compared with temperature programming.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020612

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

年代:1979

数据来源: WILEY