jagomart
digital resources
picture1_Procedure Ppt 77564 | Chiralgc


 130x       Filetype PPT       File size 2.18 MB       Source: www.csus.edu


File: Procedure Ppt 77564 | Chiralgc
chiral separations in gc outline introduction theory advantages and disadvantages applications conclusions references 2 chiral separations in gc introduction one of the limitations of conventional gc cannot be used to ...

icon picture PPT Filetype Power Point PPT | Posted on 03 Sep 2022 | 3 years ago
Partial capture of text on file.
                       Chiral Separations in GC 
                                   Outline 
     • Introduction
     • Theory
     • Advantages and Disadvantages
     • Applications 
     • Conclusions 
     • References
                                                                           2
                          Chiral Separations in GC 
                                  Introduction: 
      • One of the limitations of conventional GC
         –Cannot be used to separate enantiomers.
         –Enantiomers are nonsuperimposable mirror-image molecules. 
         –Since they have identical properties, they elute at the same time in 
           non-chiral GC.
      • However diastereomers can be separated using 
        chromatography:
         –Different chromatographic properties 
         –Different retention times
                                                                                   3
                          Chiral Separations in GC 
                                   Introduction: 
      • Chiral separations in GC can be achieved via:
         –Using a derivatization procedure with a chiral auxiliary 
         –Using mobile phase additive
          to form diastereomer complexes which then separated on an achiral 
           stationary phase. 
         –Using a non-racemic chiral stationary phase (CSP)
                                                                                    4
                              Chiral Separations in GC 
                                        Introduction: 
      •  In the late 1960s, chiral separation in GC was a challenging problem among 
         scientists. 
      •  In 1967, Prof. E. Gil-Av was successfully demonstrated chiral separation for L- and 
         D-amino acid esters with lauryl ester of N-trifluoroacetyl-L-isoleucine  as CSP. 
      •   In 1977, the first polysiloxane bonded CSP, Chirasil-VAL (thermal stability > 
         200⁰C) was developed by H. Frank, G. Nicholson and E. Bayer.
      •  In 1987, the first capillary column coated with cyclodextrins was invented by Prof. 
         W. A. Konig in cooperation with Macherey-Nagel. 
      •  In the early of 1980s, the successful separations of o-, m-, p-xylenes and 
         ethylbenzene on a cyclodextrins CSP were published. 
                                                                                                 5
                       Chiral Separations in GC 
                                   Theory:
     The main purpose of chiral separations is to determine the precise 
     enantiomeric compositions or enantiomeric excess: 
                           % ee = 100(R-S)/(R+S) 
     with R= major enantiomer
                 S= minor enantiomer of chiral analytes
                                                                           6
The words contained in this file might help you see if this file matches what you are looking for:

...Chiral separations in gc outline introduction theory advantages and disadvantages applications conclusions references one of the limitations conventional cannot be used to separate enantiomers are nonsuperimposable mirror image molecules since they have identical properties elute at same time non however diastereomers can separated using chromatography different chromatographic retention times achieved via a derivatization procedure with auxiliary mobile phase additive form diastereomer complexes which then on an achiral stationary racemic csp late s separation was challenging problem among scientists prof e gil av successfully demonstrated for l d amino acid esters lauryl ester n trifluoroacetyl isoleucine as first polysiloxane bonded chirasil val thermal stability c developed by h frank g nicholson bayer capillary column coated cyclodextrins invented w konig cooperation macherey nagel early successful o m p xylenes ethylbenzene were published main purpose is determine precise enantio...

no reviews yet
Please Login to review.