摘要:

AbstractThis paper briefly surveys three important considerations related to the tube diameter and film thickness. These are the interrelationship of these two parameters through the phase ratio, the different meanings of the term “efficiency”, and the influence of film thickness and tube diameter on sample capacity. Comparative examples are given for columns having different diameters and film thicknes

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080902

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

年代:1985

数据来源: WILEY

摘要:

AbstractInvestigations have been initiated to examine the basic elements of resolution and how they vary individually and collectively in terms of modifiers used in supercritical fluid chromatography (SFC). Capacity factors (k′) have been determined for a mixture of polynuclear aromatic hydrocarbons from SFC experiments as function of modifier identity and concentration using different stationary phases. Using carbon dioxide as the primary mobile phase, the modifiers investigated included methanol, 2‐methoxy ethanol, 1‐propanol, tetrahydrofuran, dimethyl sulfoxide, acetonitrile, sulfur hexafluoride, and fre

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080903

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

年代:1985

数据来源: WILEY

摘要:

AbstractPyrolysis‐capillary GC has been applied to the analysis of chemically derivatized polystyrenes. The reproducibility of the method and the influence of instrumentation has been discusse

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080904

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

年代:1985

数据来源: WILEY

摘要:

AbstractA simple way to elucidate the functional group substitution on silicone chains is presented. The polymer is decomposed into its monomers by alkaline hydrolysis. These monomers are converted into trimethylsilyl derivatives, which are then analyzed and identified by capillary gas chromatography/mass spectrometry.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080905

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

年代:1985

数据来源: WILEY

摘要:

AbstractMesomorphic biphenylcarboxylate esters were coupled via flexible aliphatic hydrocarbon spacers to a polysiloxane backbone. The influence of spacer length, percent mesomorphic substitution, and crosslinking of the stationary phase on liquid‐crystalline transition temperatures and on chromatographic performance was investigated. Unique selectivity and good efficiency over a wide temperature range for gum and cross‐linked liquid‐crystalline phases were demonstrated by the separation of various isomeric polycyclic aromatic comp

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080906

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

年代:1985

数据来源: WILEY

摘要:

AbstractAbout three years ago, fused silica capillary columns were introduced in the Quality Control Laboratory of the Shell refinery/chemical complex at Pernis. In general, long, thick‐film, wide‐bore capillary columns are used together with low split ratios and hydrogen as carrier gas. These conditions enable the analysis of relatively large sample amounts, resulting in low detection limits for the minor components without overloading by the major components, while still maintaining a satisfactory resolution. A number of applications are shown, such as the analysis of complex mixtures, the determination of trace impurities and the analysis of residual volatiles in polym

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080907

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

年代:1985

数据来源: WILEY

摘要:

AbstractOrganic compounds adsorbed on fly ash from an incinerator for radioactive waste were investigated. Following Soxhlet extraction and concentration, analysis was performed by GC and GC/MS using high temperature silylated glass capillary columns coated with OV‐1 and SE‐54. Compound identification was based on retention data, relative detector responses, and mass spectra. Among other polycyclic aromatic compounds, series of gradually chlorinated PAHs containing four to seven aromatic rings were detected. For unequivocal identification, appropriate reference compounds were synthesized by chlorination of the corresponding parent P

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080908

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

年代:1985

数据来源: WILEY

摘要:

AbstractA simple interface between a capillary supercritical fluid chromatograph and an Extranuclear Simulscan mass spectrometer is described. The SFC column is directly inserted into the ion source through the existing GC‐interface. The system is equipped with a splitting device which allows simultaneous EI/MS and flame ionization detection when CO2is used as the supercritical phase. The effect of source temperature and pressure on CO2clustering was studied for optimization of source conditions. The performance of the system was evaluated with a series of model compounds and standard mixture

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080909

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe practical applications of open tubes in liquid chromatography as separation columns and as reactors for post column derivatization are discussed. With present technology, the potential efficiency of open tubular columns cannot be fully exploited. As reactors in post column derivatization, these tubes offer many advantages if knitted or stitched to enhance radial mass transfer. The application of open tubes with diameters between 0.12 mm and 0.6 mm as reactors in the selective and sensitive detection of amino acids is demonstrated.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080910

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

年代:1985

数据来源: WILEY

摘要:

AbstractPolyethylene glycols can be immobilized in glass capillary columns by a new procedure involving covering the glass walls with a layer of graphitized carbon black and by flowing a mixture of the stationary phase and dicumyl peroxide. After curing and conditioning the column is ready for use. Excellent performance is reported for Carbowax 20 M and high molecular weight glycols. For other glycols the immobilized layer is less stable and can be washed out.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240080911

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

年代:1985

数据来源: WILEY