Page 47 - Basic Gas Chromatography
P. 47

33     still   and   (11)   as:   (12)   where   inter-   mobile   (13)   factor,   from   calcu-   a   of   (14)   a   for   (15)   through   is   12
            is            written       significant   compare            k.   be   time     Similarly,   time   equation
            There   adjusted   be   chromatographers   situations   no   used   be   to   is   the   of   retardation   directly   to   can   varies   in

            rate.   both                is   there   can   solute   velocity   relationship   velocity   retention   seconds.   retention   phase   used

            flow   is   that   ~ VM   appropriately   gas   in  volume   LC,   values   a   of   the   calculated   solute   the   in   is   the   mobile   the   value   the
            average   value   Vy:   VR   =   more   making,   In   two   behavior   average*   called   is   be   can   interesting   the   by   L,   time   from   of   so   gas,



            the   the   volume,   Va   KcVs   are   retention   volume.   the   the   13   too   column,   £L   tr   retention   calculated   OL   2   velocity   carrier   u.  as
                                                               =R
            on   retention   =i   Vu)   should   9   =   Vn   they   retention   and   phase   retention   with   y.,   RR   equation   it   used,   an   bears   definition,   the   B=   the   is   -   u=—   linear   the   the   of   designated

     Symbols   and based   representing   net   —   (Va   equation   point   adjusted   the   net   mobile   the   column,   by   widely   it   and   computational   of  length   and   velocity   air:   that   2   compressibility   usually


      and   gas   volume   the   = j   Vy   GC,   particular   the   the   express   the   defined   too   data,   the   mm   or   gas   like   Chapter   velocity,

      Terms,   carrier   the   retention   called   is   it   for   the   on   substitute   to   using   be   of   Factor   to   way   through   u:   parameter   not   is   it   a   at   dividing   cm   in   is   linear   peak   from   the   to   due   linear


      Definitions,   of  sibility   another   corrected;   Consequently,   Depending   free   feel   should   they   compressibility   changeably.   Retardation   Another   velocity   its   phase,   gas   new   The   While   R.   chromatographic   arrive   To   by   lated   solute,   given   L  where   average   the   nonretained   Remember   ®   column   the   average   the













      Terms   volume.   (9)   the   to   often   measured   1.5.   the   from   solute   3.1   Table   the   Thus,   solute,   can   it   extent   for   case   2.   above,   in   given   not   are   the   void   the   9;  equation   compres-

      and               parameter   time   Figure   yields   7   directly   any   for   in   phase,   factor.   given   and   relative   the   equation   given   was   two   definition:   in   the
      Concepts   retention   proportional   the   retention   in  shown   equation   measured   factor   included   there.   stationary   retention   for  a   chromatogram,   the   usually   from   was  volume   volume   these   particular   excluding   shown   for   k=3   k.



      Basic   adjusted   directly   therefore   was   into   be   retention   are   k   tabulated   the   the   known   be   measure   is   (as   calculated   retention   that   sure   volume   as   correcting   k=2   4   factor,

             the   KcVs   is   the   is   as   it   can   of   by   is   not   the   to   known   be   retention   own   peak)   value   3   ——»   retention
             Vp,   =   which   and   it   methane)   (¥2)   Vy,   the   values   types   retained   larger   may   from   constant   is   can   make   its   retention   air   or   the   k=1   2  (mins)
             term,   Va   =   essence   substituting   and   determine   column   is   the   measured   8   if   constant   adjusted   corrected   to   has   the   is   VR,          Time   of

             new   Vm   volume   constant   In   or   Vu   Ve   Relative   the   and   constant   the   ought   Each   is   methane   Non-retained fil   1   Illustration

             a    —   Ve     (air   and   9   k:   of   volumes,   to   3.1.   of   solute   volume   readily   distribution   However,   the   of   of   we   Vg   the   volume,       |_|
             produces   retention   distribution   equations.   peak   equation   definition   easy   is   a   more   distribution   is   the   solute.   distribution   definition   definition   4),   another.   volume,   from       0   3.1.   Fig.


             it       adjusted   nonretained   retention   it   Figure   in   comparison   the   retention   the   factor   of   a   by   the   the   (equation   one   retention   (measured   retention
             rearranging   the   thermodynamic   theoretical   in   the   Rearranging   working   both   chromatogram,   illustrated   the   in   that   Note   the   is   though   retention   instead   used   sorption   columns),   Because   related   a   2   with   corrected





      32     and      is   It   used   from   useful   Since   a   as   aid   to   larger   even   the   be   of   OT   and   Chapter   confused   adjusted   volume   the
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