Page 161 - Basic Gas Chromatography
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in-   neede   a   and   a   In   differen   the   ot   ——   he   e   mee   flo   in   initia   about   at   fow   is   )   constant   ;   mus   impurities)   to   before   en-   Over

                            temperature   injection port   and   1s  programmer   fan,  volume   flow.   gas   a   with   upstream   regulation is   canno   valve   curing  decreases   viscosity.   change   the   the   set   to   expected   |  adequate   (  control   a  maintain   the Stationary   and   gas   carrier   phenomenon   this   solution  common   line   gas   the   phases.   pressure   N)


                      drift

                 detector)   electronic)   or   remove   to   programmed   detector   high   a   —  programmer.   carrier   the   accomplished   line   gas   the   pressure  constant   control   flow   gas   gas   in  increase   low,  relatively   is  solution   flow   the   to   an   insure   pressure   to   I   [3].   gas  carrier   the   list,   (and other volatile   since   run)   One   run.   in   dryer   a   liquid   of   vapor   low   high




        PTGC     column,   pneumatic   the   the   temperature   mass,   low   the   control   usually   in   a   and   carrier   of   the   is   One   closer   will   This   electronic   be   can   run   the   the   instrumentation   water   a   of   start   PTGC   sieve   requirements   PTGC   with   temperature


        for      (injector,   compensation   control   keeping   electronic   a   has   by   to  provided   is   this   placed   valve   chromatograph,   sampling   rate   flow   to   due   column   columns.   and   value   program.   However,   it   and   during   on   placed   of   the   the   molecular   the   for  Phases   (200°C)   low   a)  high
        Requirements   programmer   (differential   column   to   ability   while   oven   An   that   controlled   control   the   run   OT   an   packed   optimum   the   instruments   pressure   PTGC   the   accumulation   (before   during   SA   a   of   Liquid   range   at   (for



  NAN            ovens   or   phase   the   design   also   usually   chromatograph,   column   across   in   than   through   the   in   inlet   peaks   insert   some   viscosity   solubility
  A         gas                   temperatures.   flow   split/splitless   consequence,   temperature   the   temperatures.   requirements are   the   of   of   temperature
  Lf             separate   controller   liquid   is   column   oven   air,   is   some   ghost   to   list
  Up    Instrumentation   carrier   Temperature   column   important   the   an   outside   means   column   port.   capillary   for   drop   severe   above   way   on   increasing   indicated   prevent   column   in   is   is a   Requirements   range   Reasonable   Selective
  ENC GAEICIILEHEGS   Dry   1.   2.   Three   3.   Flow   4.   Dual   5.   Suitable   6.   Most   in   crease   constant   at   with   along   to   vent   Some   packed   pneumatic   tial   injection   a   on   required   a   As   used.   programmed   pressure   the   less   is   rate   rate   flow   the   of   70%   higher   the   available   by   w   nother   As   phase.   to   dry   be   cool   the   at   result   will   problem   this   instrum











   Temperature   for  especially     separation   a   used   the   get   to   typically   samples.   new   ob-   is   has  sample   operation.   The   GC.   30%  Chromosorb  FFAP   on   W





  Programmed   range   precision,   optimizing   for   are   steps   programmers   screening   for   composition  sample   when   entire   the   isothermal   with   isothermal   does   x ve  DMCS  10°   Mesh   temperatures  shown   mi/min.   N,   Tt   60   oil.






         point   and  shapes,   required   phases   time   of  PTGC   programming   time.  Modern   ramps.   good   is   about   the   tell   can   make   to   than   page.   next   Dual   60/70   at   25       T   48   orange   of

         boiling   peak   cleaning   temperatures   liquid   cooling   operation   one   judgment   instrument   the   f   x   PTGC


         wide   limits,   column   instrumentation   suitable   application   multiple   minimum   temperature   information   Usually   on   ,      T   %   Multistep

         of     of         high   of   considering   of  the   Here   the   temperature   of   time.   difficult   PTGC   OF   versatile   listed   %   T   m   9.3.
         separation   detection   eluting   peaks   means   complex   at  signals   number   slower,   example   Figure   9.3.   in  separation   five   as   amount   minimum   often a   more   a   are   XBT  ><   eo           Fig.




        Better   Improved   late   Excellent   Disadvantages   More   Noiser   Limited   be   May   Another   in   many   as   Programmed   maximum   in   eluted,   REQUIREMENTS   requires   requirements       20       12



  140   3.   4.   5.    1.   2.   3.   4.   shown   optimum   provide   -tained   been   PTGC   major   225   —   —   i  xe  Luvs
                                                                                                  —-4  i.
                                      is       A                                 200°—-   1s   150°—   125°—   100°—
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