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105     be   to   with   that   detects   classes   not   very   halogen-   are   is   This   is   enhanced   for   the   of   example,   forest   are   are   send   of   constant.   the   It   is   it   baseline   the


          Consequently,   are   they   used   be   analytes   or   types   is   FID   is   ECD   like   detectors   detected.   composition   has   analysis   concentration.   few   a   an   a   in   analytes   identifications   destructive   and  stream   produces,   time   for   sample.   a   of   Usually   the   from   arise


          cases.   if   also   of   theoretically   particular   the  selectivity;   the   while   species,   universal   are   whose   that   trace   of  higher   only   As   rest.   compounds   separated   when   utilize   to   effluent   analysis.   it   signal   and  noise   background   a   absence   baseline.   Ideally,   do


          some   volumes   may   gas   percentage   detector   The   solutes   samples   detector   provide   detecting   the   sample.   the   way   the   for   rest   the   are   provide   the   the   on   signal.   fluctuations

          in   small   signal.   or   to   of   compounds   electronegative   can   compounds   by   “ignoring”   sulfur-containing   fuel   if   example,   One   split   the   is   in   detector
          solution   very   Make-up   the   number   universal   A   responds   degrees   advantages.   eluted   all   new   of   selective   a   compounds   other   chromatogram   jet   or   necessary   for   as,   instruments.   to   be   collecting   characteristic   characteristics   to   first   detector   a   appears   it   normal   random



          satisfactory   have   must   GC.  capillary   decreasing   the   to   refers   system.   given   type  selective   differing   are   organic   all  detects   very   only   have   sure   be   to   screening   hand,   other   of   class   of  presence   selectively   and   only  detect   gasoline   a   in   Nondestructive   are  detectors   analysis,   auxiliary   would  situation   detector,   CHARACTERISTICS   detector   important   discu




    Characteristics   a  signal—not   detectors   for  successfully   of   risk   the   at   Universal   vs.   category   a  detected  by   the   while   There   and   detects   and   pesticides.   detectors   of   types   wants   one   qualitative   for   the   On   small   a   for   the   in   even   complex   a  simplify   present,   selectively   can   peaks   vs.   Nondestructive-type   for  further  reclaimed   using  performed   a   such   i





    Detector   resulting   concentration   used   but   them,   Selective   detector   This   be   can   solutes,   all   compounds.   of   selective   very   selective   containing   Both   when   used   important   known.   not   sensitivity   class   that   can   It   compounds   FPD   the   hydrocarbon   of   Destructive   be   to   be   to   detectors   part   only   DETECTOR   most   The   course,   latter   The   discussion   Noise   is   No










    Detectors                                    concentration   John  Contrasts,   Inc.  Sons,   &   between   is   both   types.   specifi-   the   are  volumes   concentration   magnitude   concen-   of  a   contained   in   broadened   width   the   the  where   have  might   mL  0.017   the   same   the   peak   a   have   make-up   the  through   rate   flow   case,   the   well   the   as





                0.5mL/min             awe        (a)  detector:   Concepts   and   Wiley  of  John   comparison   for   mass   requires   internal   However,   the   and   volume   cell   be   could   badly   be   since   40,  width,   column   of  volume   were  volume   and   time   one   situation  should   not  possible   sample   mass   for   latter   the   In   as  concentration




          rate                                   of   types   courtesy   better   of   units   types   their   occurs   the   sample   would   requirements,   base   capillary   a   detector   at   it   this   is   this   the  sweep   helpful

          Flow                 (a)            (b)   two   Chromatography:   the   the   detector   when   minimized.   detection   Suppose   peak   (the   a   represents   in   for   When   to   be   detectors.   the
                                                 the   Reproduced   has       entire   volume   units   from   the   contained   will
                                                 for        units;   between   concentration.   optimized   thereby   which   the   resulting   cell   peak   which   If   detector   4L.   effluent   lowering
                mL/min                           sizes  peak   M.,   J.   91.   p.   different   which   is   is   in   importance.   that   of  the   of  ideal   volume   in   narrow   mL/min.   be   ideal   say   2   remedy   concentration



                                                 on              comparisons   and   detectors   volume   large   shape   An   volume,
                1                                  Miller,   1987,   quantity               second,   1   could   column   This   sample,
                                                 rate   From   York,   have   rate   broadening   special   so   made   expressed   A   1   of   peak   the   for   the
                                                 flow   of   rate.   Inc.,   New   signals   detectable   valid   flow   all   of   band   a   cell   has   is   The   be   can   be   units).   as  small   flow   rate   entire   broad.   smaller   to   added   quickly.   so   less   dilutes
                                      rate
           Detector   type   Concentration   flow   Mass   Effect   flow   mass   Sons,   &   their   second,   the   of   Operation   since   have   volume   detector   volume.   distorted.   Estimates   can   peak   mL   in   is   as   a   at   the   very   be   be   more   but   gas



    104                                          7.1.   Fig.   (6)   and   Wiley   because   minimum   And   cation   small,   detectors   that   of   tration   cell   one   and   of   a   x-axis   width   a   wL)   (17   larger,   or   would   significantly   can   gas   detector   detectors   make-up
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