Page 74 - Basic Gas Chromatography
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Phases   61   GLC   for  Phases  Stationary   of  Classification      partici-   is  number,  plate  larger   a  having  column,  capillary   a   1.1;   ut   and/or  about 1.02.   to  down  a-values,  smaller  of.  solutes with  vaired  fon vexolation   any   in  changes  effecting   by  accomplished   be   can  separation   a  Improving   interactions.  columns,  packed   For   a.   or   k   N,  parameters,  three   the   of   the  is often


    Stationary   chromatography;   bond  donors   unwanted   the   to   these   called  peaks   often   be   solid   on   and   Chapter   5.   treated   be   Rather,   measurements,   relative   chromatogram.   For   relative   equation   in   factors   represents   it   stationary   and   the   us  difficult   how   the   a,   easier   and   no   indicate   the   phase,   given   equation   2.   can   it   peaks   with







          in   hydrogen   cause   become  attached   tubing.   Often   nonsymmetrical   shape   can   walls   the   discussed   in   forces  cannot   molecule.   empirical   measuring   a   their   of   As  noted   retention   of   As   such,   the   and   forces   tells   it   value   of   solubility   that   a  stationary   on  solutes   a   given   by   ()   assumptions,   resolving
          important   as   also   can   can   column   peak   on  groups   is   a   for   given   from  molecular polarity.   from   ratio   the   (K,)2  ko       (Key   ki   peak.   ratio   the   peaks.   solutes   intermolecular   practice,   larger   the   differential   constants   and   two   resolution   is   of



          very   classified   bonding   bonding   and   to   rise   in   supports   intermolecular   value   calculated   parameter   determined   is  factor   eluting   to   two   the   of   the   relative   In   are   k   solute   a   for   (44)   reasonable   capable   is

          are           giving   asymmetry   hydroxyl   a   (Va)2       (Vii   second   equal   for   each   difference.   solutes—the   no   is   and   solubility   and   (e>)
          they   usually   hydrogen   supports,   solid   of   all   “polarity”   indices   represent   a,   is   be   separation   _   the   also   the   there   K.   between   a   making   column
          and   are   acceptors.   hydrogen   desorptions   surface   of   effect   a   and   to   factor,   can   is   is   constants   between   express   or   two   1.00,   summarize:   forces   between   Re =   and   packed
          forces   bond   of   of   solid   undesirable   the   Silanization   produce   devised   Factor   value   the   volumes   Vp)2   factor   to   similarity   these   =   «   differential   equation,


          strong   molecules   strength   capable   ports,   slow   in   This   derivatizing   combined   to   measurements,   been   separation   its   peaks,   so   that (   separation   distribution   interaction   used   be   their   separate   If   To   intermolecular   the   relationship   good,   a

          tively   pating   hydrogen   The   Solutes   injection   result   peaks.   surfaces.   The   retically   Separation   constants;   adjacent   retention   defined   of   can   of   separation.   possible.   expresses   The   this   that
   60                       by       cal   have   The               the   ratio   relative   and   tude   to   is   is   of   phase.   Using   lated
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