ISSN:0935-6304    

DOI:10.1002/jhrc.1240020502

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

年代:1979

数据来源: WILEY

摘要:

AbstractChromatographic methods are presented for the determination of chloramphenicol, erythromycin, tyrothricin, nystatin, penicillin, streptomycin, sulphanilamides and nitrofurans, in some pharmaceutical formulations. The methods have been applied in routine analysis and are in general capable of distinguishing the main antibiotic from decomposition products and likely congeners.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020503

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

年代:1979

数据来源: WILEY

摘要:

AbstractA novel sampling system for isothermal capillary gas chromatography of medium‐ or low‐volatility mixtures is described and test results are reported using flame ionization detection. The system features a loading and positioning chamber for glass vials which can carry a dilute sample in up to 0.2 ml of a volatile solvent. The output from the glass vaporization chamber is trapped onto a packed precolumn operated in the backflush mode. The analytes are further transferred over a wall‐coated capillary trap prior to isothermal capillary GLC. Repeat‐cycle operation of the sampling system requires 10 channels of a processor for time control over 5 solenoid valves and 3 static heaters. Preliminary results with long‐chain n‐alkanes in the submicrogram range showed no unwanted effects. The principal claim of the system is an improved rejection of no

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020504

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

年代:1979

数据来源: WILEY

摘要:

AbstractTwo new sample preparation procedures that produce solvent‐free extracts especially suitable for use with high resolution GC are described. One is based on Soxhlet extraction in a pressurized container that permits the use of liquid carbon dioxide as the extractant; the other utilizes refluxing difluorodichloro‐methane (Freon 12) to isolate entrained volatiles from gas stre

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020505

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

年代:1979

数据来源: WILEY

摘要:

AbstractA new all‐glass interface for GC/MS designed to fully exploit the potential of glass capillary columns is described. The system works in the open split mode and has high versatility with respect to column changing. It is especially suitable for mass spectrometers, which are not exclusively dedicated to GC/MS work. Two chromatograms illustrate the properties of the described interfac

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020506

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

年代:1979

数据来源: WILEY

摘要:

AbstractGel chromatographic behavior of 8‐hydroxyquinoline (oxine, abbreviated HOx) complexes of zinc, copper, aluminum, gallium and indium has been investigated on thin layers of Styragel 60A and Merckogel OR‐PVA 2000 mostly in chloroform and p‐dioxan media. Except for the stable Cu(Ox)2, the other oxinates exhibit either hydration or decomposition in gel‐solvent‐solute systems, which leads to strong retention or tailing on gel layers. An excess of 8‐hydroxyquinoline present in solvents allows the oxinates to be stabilized, so that well‐defined compact spots come out and migrate. For the Zn(Ox)2the formation of a self‐adduct is strongly suggested on the basis of gel chromatographic behavior. Elution with the solvent containing pyridine also yields evidence of the adduct formation of zinc oxinat

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020507

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

年代:1979

数据来源: WILEY

摘要:

AbstractThin‐layer adsorption chromatography with a multicomponent mobile phase is discussed. A new equation for predicting RM‐values in TLC with mixed mobile phases using the RM‐ValUeS obtained for pure solvents is proposed. This equation takes into account effects of energetic heterogeneity of the adsorbent surface with regard to adsorbed molecules of solvents and solutes. Experimental verification of this equation is presented for RM‐data obtained by TLC using a binary mobil

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020508

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

年代:1979

数据来源: WILEY

摘要:

AbstractIn order to avoid splitting at the column outlet for simultaneous multidetection, a new line of detector heads with the ionization cells coupled in series has been developed.The electron capture plus flame ionization detector (EC+FI‐D) has been evaluated from the point of view of the sensitivity, the linear dynamic range and separation efficiency in a capillary column GC system. The performances of each section are the same as when a single ionization detector head is use

ISSN:0935-6304    

DOI:10.1002/jhrc.1240020509

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.1240020510

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.1240020511

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

年代:1979

数据来源: WILEY