摘要:

AbstractThe C1‐C6fatty acids present in various types of heterogeneous animal wastes were isolated by steam distillation and determined as benzyl esters by high resolution gas chromatography. Glass capillary columns, deactivated with barium carbonate and coated with UCON HB 5100, allowed the analysis of benzyl formate, acetate, propionate, isobutyrate, butyrate, isovalerate, valerate, and caproate in less than 20 minutes. Recovery tests, performed on more than 50 different samples, indicated a benzylation yield and an overall efficiency higher than 99%, with a standard deviation of 2.6% (C5) to 6.0% (C1). The absolute detection limit ranged from 0.3 picomole (caproic acid) to 1.0 picomole (formic acid

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040202

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

年代:1981

数据来源: WILEY

摘要:

AbstractAn HPLC method has been developed for the determination of the cephalosporin antibiotic Ro 13‐9904 in plasma, urine, and bile of dogs and of human volunteers using the technique of ion‐pair chromatography with a LiChrosorb RP‐18 column. The three mobile phases employed contained tetrapentyl‐, tetraoctyl‐ and hexadecyltrimethyl‐ammonium bromide, respectively, as lipophilic counterions. The chromatographic conditions chosen allowed simple and rapid sample preparation. Plasma was deproteinized with ethanol and the supernatant was directly injected onto the column; urine and bile were diluted with mobile phase and injected without any purification. The detection limit for the cephalosporin was about 0.5 μg/ml for plasma samples and approximately 5 μg/ml for b

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040203

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

年代:1981

数据来源: WILEY

摘要:

AbstractAn integrated gas chromatography/Fourier transform infrared spectrometry (GC/FT‐IR) system developed for the analysis of environmental pollutants is described. The versatility of the system allows the utilization of many different techniques of sample introduction and manipulation during analysis. The sample can be introduced by direct injection or thermal desorption from an adsorbent cartridge, and can then be separated on one of two capillary columns and detected by FT‐IR or an FID. Cold traps and collection cartridges incorporated in the system permit recovery and additional fractionation of samples. Recovered sample and sample fractions can then be re‐analyzed by GC/FT‐IR or subsequently analyzed by GC/MS or other

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040204

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

年代:1981

数据来源: WILEY

摘要:

AbstractA rapid and specific procedure is described for the resolution of nine steroids present in conjugated estrogen preparations. Resolution is achieved on a short glass capillary column coated with Silar 10C after dual derivatization to oxime‐trimethylsilyl ether

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040205

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

年代:1981

数据来源: WILEY

摘要:

AbstractThis paper concerns the application of excess adsorption isotherms, measured for solvent mixture/adsorbent systems, to the characterization of TLC data. For this purpose the excess adsorption isotherms for three liquid mixtures: cyclohexane/ benzene, benzene/acetone, and carbon tetrachloride/ethyl acetate on silica gel at 20°C have been measured. These mixtures have been used as binary mobile phases in TLC measurements. It has been shown for a given solute in binary mobile phase that the quantity RMis a simple function of the excess adsorption. Parameters of this function have been used to characterize chromatographic systems with binary mobile phases

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040206

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

年代:1981

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040207

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

年代:1981

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040208

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

年代:1981

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040209

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

年代:1981

数据来源: WILEY

摘要:

AbstractA multidimensional switching system with two packed columns has been used for the analysis of volatiles. Use of a high‐boiling solvent and the backflush mode permitted total resolution of the mixture discussed in a short analysis tim

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040210

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

年代:1981

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240040211

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

年代:1981

数据来源: WILEY