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155                        have   MS   the   of   done   GC-MS   high   rates   GC-MS   better   results.       Vacuum)
                      Heated       methods   an   to   system   compounds   with   nano-grams).   or   that   is  problem   vacuum   a   to   be   must   interface.   Most   inert,   an   flow  capillary   Bench-top   provide   GC   of   Source   MS      |          Vacuum   Source   MS   To   (Separate
            Interfaces   High   >  Separator   Columns)   Direct              MS.   to   GC   of   other   of   variety   a   GC   a   of  coupling   the   deal   both  (200-300°C),   (micro-  samples   small   only   The  compatible.   reduced   be   must   GC   two   the   of  coupling   The   an   with  accomplished   today.   use   in  interface   permits   tubing   silica   fused   For  systems.   two   the   possible.   is  interface   they
             Vacuum
              (108  Torr)
          MS
















             o>   Jet   A.   (Packed   Capillary   B.       Coupling   10.2.   Fig.   chromatograph,   a   schematically   heated   are   require   both   and   very   are   the   of   output   inlet.   MS   the   is   and  pressure,   common   a   shows   and  columns,   between   transfer   direct   a   less,   low   these   handle   sample)   total   of   Interface  Direct   Heated         |      (Packed   C_   e   10.3.   Fig.
             Gc   Pressure     (200-300°C)       with   use   For   shows   10.2   systems   Both   state,   systems   MS   pressure   for   torr   10-°   of  reduction   10.3A   capillary   use   direct   or  mL/min   easily   can   (transfer   Capillary   Oven   GC   7   Column   Separator   Jet   Flow,   Column






    GC-MS     Atmospheric   Heated       solids.   of   used.   been   Figure   system.   vapor   the   in   and   GC   atmospheric   to   10-5   a   with   Figure   systems   efficiency   5   of   systems   sensitivity   A)   Silica  Fused   B)







   Topics   GC   information   d ta   (structure,   ™   mono   of   often   is   sample   with   and   introduction


   Special   i   unique.   not   provides   quantitati   the   in   spectrometer   it   size,   of  amount   introduce gaseous   inlet   An   solids;   of       DETECTOR              DATA   SYSTEM



            are   most   it   but   compounds   their   as   found   follows.   mass   small   to   source.   solutions   the   for
            they   the   of   one   sample,   of   unknown   well   as   system.   be   can   topic   the   resolution   its   of   small   very   a   used   be   ionization   or  liquids,   means       <—S       spectrometer.

            to identity peaks,”   hand   is   micrograms   of   weight),   GC   a   GC-MS   to   low   Because   of   can   bulb   the   into   of   common   a   is       MASS   ANALYZERS             mass   a   of




          well-defi   other   identification   molecular   to   about   introduction   typical   a   GC.   introduction   gas   large   introduction   system              VACUUM         SPECTRUM   Schematic



          a   the   only   coupled   of   with   MS.   the   A   pinhole                               |         m/z
          of   used   be   on   requires   and   information   an   but   schematic   used   bench-top   for   small   easy   interlock   —   MASS   |   |   10.1.   Fig.
          characteristic   cannot   spectroscopy   It   qualitative   composition,   easily   is   it   complete   [1-5],   a   is   commonly   as   a   allows   of  sources.   a  through   allow   vacuum





          are   alone   Mass   detectors.   the   both   elemental   addition,   More   listed   Instrumentation   10.1   type   to   Inlets   sample inlet   a  variety   would   a       SAMPLE   INLET         v   IONIZATION   SOURCE

   154    they   data   rich   for   In   graphs   Figure   the   referred   Sample   A   from   samples   septum   finally,
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