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49    run   time   the   linear   well   is   (30)      (31)   in       ways   given   since   to   of   and
           and   evaluated   calculate   versus   as   between   Deemter   equations—one   former   summarized   for   carrier   of   optimize   a   higher   better   Figure   to   velocity   20   would   longer   minimum   smallest
           chosen   sufficient   is   to   noted   is   van   Golay   The   rou   look   effect   to   For   plates   the   it   is   gas   about   nitrogen   times   the   the


           is   allow   number   used   plotted   velocity   Comparisons   The   and   rate   11k)   De   wdpu   Deg   is   the   choose   time.   more   having   however,   Referring   linear   at   H,   3.3   beyond   has
           solute   to   plate   then   are   column.   two   columns.   k)*   +   equation;   ,   ___   Ds,   performance   chromatographers   can   analysis   generate   Nitrogen,   at a   occur   minimum   time   gas,

           A   sure   The   and   values   minimum   velocities.   best   Deemter   only   packed   ,Ut6kt   (1   24   __8kdiu   it+kP   compare   One   the   H.   analysis,   hydrogen.   hydrogen   at   analysis   curves   lightest
           conditions.   being   rates,   change.   19  equation   height   The   higher   the   of   H.   van   of   considering   for   one       Ds   Deemter       ,   Wr   chromatographic   that   us   let  time,   column.   or   will   gas   (B-term).   minimum   of  speed   helium,   or   minimum H   and   were   run   an   at   but   the   of  slope   the





           operating   flow   of   after   each   using   plate   The   15).  equation   the   at   selection   calculate   to   Equations   by  discussion   and   equation:   _2kdiu   +   3(1   k)?   extended   van   4yDo   +   u   suggestion   analysis   capillary   a   for   number)  (plate   weight   minimized   lower   a   the   like   gas,   has   its   helium   for   gases   all   plates,   the   hydrogen,   that



           the   variety   equilibration   chromatogram   20).   by   curve   the   the   in   used   Rate   columns   Golay   u   the   2ddy   improving   earlier   and   H   equation   molecular   is   shows   optimize   carrier   nitrogen   minima   If   more   examine   see

     Theory   and   it   a   at   (equation   (obtained   of   help   will   seldom   of   the   conclude   this   tubular   the   by   ya2De,   by   latter   =   H   in   section.   Implications   our   to   both   rate   efficiency   higher   diffusivity   weight,   to  wishes   lighter   that   sees   The   respectively.   about   15%   must   we   3.13.   We


    Rate   evaluate   isothermally   pressure   each   height   slope   is   Summary   us   open   represented   the   value   following   minimize   the   column   a   solute   one   one   cm/sec.   cm/sec,   hydrogen.   Finally,   Figure

    The    to   for   from   plate   velocity   the   as   columns   equation   A   Let   for   and   Their   the   Practical   Returning   to   on   gas   the   column,   the   molecular   If   choose a   3.13,   12   40   generate   than   in









    Terms                                                               Chromatogra-   of   the   at   yields   the   de-   the   relative   3.12,   from   has   practice.   order


    and                                                     B             permission   out   since   it   increased,   have   get   to   the   Figure   about   attention   shortly.   in   in
    Concepts                                                      40    Gas  Column   by  Reprinted   carried   curve   be   chromatographers   equation   examining   in   comes   most   covered   useful   one   column



    Basic                                                      g          1984.      would   be   the   in   can   By   equation   increased   be   will   a   is   one’s

                                                                  30      Open- Tubular   velocity   Deemter   overall   Therefore,   it   for
                                                                     s71   Inc.,       minimum   time.   is   that   concept,   plot
                                                                     om   of   Sons,     the   van   the   topic
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                                                                  20    Courtesy                         a
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