ISSN:0935-6304    

DOI:10.1002/jhrc.1240140102

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

年代:1991

数据来源: WILEY

摘要:

AbstractA summary of the recent advances in SFC/MS is included in this review. Interface designs are described as well as the key control variables. Finally, future developments in SFC/MS are predicted.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140103

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe performance of an integrated capillary electrophoresis system with a novel split‐flow sample injection mechanism and special high sensitivity UV absorbance detector is described. Sample introduction into the capillary is accomplished with a standard HPLC‐type microliter syringe. The injected sample is divided proportionally between the separation capillary and an adjustable splitvent. The volume of sample introduced into the capillary can be manipulated by varying the length or the i.d. of the splitvent tubing; or the volume of sample injected. Data are presented showing reproducibility of retention time, peak height, and peak area; minimum detectability; and operation at short UV waveleng

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140104

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

年代:1991

数据来源: WILEY

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140105

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

年代:1991

数据来源: WILEY

摘要:

AbstractAn approach is described for optimizing chromatographic conditions for dual‐column analysis of U.S. EPA Method 608 pesticides. Sample throughput for environmental analysis of pesticides can be increased by performing the screening and confirmation analyses at the same time. This requires simultaneous injection, separation, and detection in a GC with dual inlets, columns, and detectors. Resolution maps for flow rate and temperature relationships of poorly resolved peak pairs for 5%‐phenyl methyl silicone and 7%‐cyanopropyl 7%‐phenyl methyl silicone capillary columns are presented. Resolution of target pesticides on the 5%‐phenyl methyl silicone column was much more sensitive to changes in flow and temperature‐ramp rates than was the 7%‐cyanopropyl 7%‐phenyl methyl silicone column. Optimal conditions resulted in a run time of appro

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140106

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

年代:1991

数据来源: WILEY

摘要:

AbstractA comparison of separations conducted in sodium dodecyl sulfate (SDS) and SDS modified with Brij 35 indicates that selectivity, in Micellar Electrokinetic Chromatography (MEKC), is governed by the composition of the micellar phase. Beyond selectivity optimization, resolution may be improved by increasing efficiency or decreasing electroosmotic flow. Of these approaches, increasing capillary length (to improve efficiency) should be a more time effective means of improving separation.

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140107

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

年代:1991

数据来源: WILEY

摘要:

AbstractCapillary supercritical fluid chromatography was performed using solvent‐vented injection in conjunction with a thermionic ionization detector. Mixtures of organo‐nitrogen and phosphorus containing agrochemicals were chromatographed and detection of low picogram quantities was obser

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140108

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

年代:1991

数据来源: WILEY

摘要:

AbstractAromatics of a C15C30mineral oil fraction, the “batching oil” used for producing jute fabrics, were analyzed for estimating the toxicity of oil transferred from jute bags to foods. Group‐type pre‐separation according to ring systems occurred on a LC NH2column with pentane and small additions of methanol as eluent. LC fractions were characterized by LC‐GC‐MS and quantitated by LC‐GC‐FID. The oil contained 23% aromatics and 1% “polars”; some 99.5% of the aro

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140109

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

年代:1991

数据来源: WILEY

摘要:

AbstractInternal structures of wide‐pore packing materials for HPLC were studied by transmission electron microscopy (TEM). TEM gave information about the size, shape, and location of the pores as well as the size of primary structures in corpuscular systems. Visualization of the three dimensional internal structures of wide‐pore materials was attempted by scanning the TEM photographs with a densitome

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140110

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

年代:1991

数据来源: WILEY

摘要:

AbstractGas chromatographic analysis of natural pyrethrins in insecticidal pyrethrum extract and in insecticide formulations is achieved by on‐column injection with hydrogen as carrier gas under constant flow and programmed pressure conditions. Short thin‐film fused silica capillaries (DB 5 and DB 1701) coupled to retention gaps separate the pyrethrins (cinerin I and II, jasmolin I and II, and pyrethrin I and II) and their analogueS‐bioallethrin (Esbiol) in less than twelve minutes at temperatures below 210°C without any discrimination, degradation or isomerization of thermally labile pyrethrin I and II. WithS‐bioallethrin added as internal standard, spray and powder formulations are extracted with ethyl acetate and analyzed by gas chromatography with flame ionization detection for pyrethrum constituents, for other pyrethroids such as tetramethrin, cyphenothrin, cypermethrin, and for the commonly used synergist piperonl

ISSN:0935-6304    

DOI:10.1002/jhrc.1240140111

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

年代:1991

数据来源: WILEY