Page 149 - Basic Gas Chromatography
P. 149

135      area   un-   3   °)   areas.     is   in          can   made   The   un-   ‘   pub-   values   and   packed
               of   the   is     the   met:     and   analytes   use   (for   running   by   (it   response   are   unknown,   of   the   been   FID   accuracy,   multiplied
               calculation   X   If   all   of   must   be   (response/mass).   simple   is   some   if   form   removed   substance   its   and   weight,   chromatographed.   the   and   factor   standard.   have   representative   the   for   using   highest   and




               a   percent.      sum   the      method   or   pure   be   One   standard,   by   response   the   compounds   8.3   obtained   the   measured   before:
               really       10   is   criteria   this   sufficient   in   can   f.   Mixtures,   are   standard   to   some   Table   were   For   is   as

               is   weight   to   Ax   =F  |   iy   denominator   following   sensitivity   but   is   available   limitation   factors,   the   as   1.00.   they   and   the   relative   (2)   unknown   common   and   given   in   they   bleed.   area   calculated
               normalization   equal   be   =   %X   =   the   the   detected.   same   met,   rarely   analysis   not   are   Factors   third   response   chosen   is   like  value   analytes,   for   A,   and   the   and   pox (4)   the   of   some   detectors,   are   [16]   since   and   column   factors.   own   run,   is   each   is






               area   assumed   to   area   and   X   of   accurate,   eluted.   be   be   the   have   are   semiquantitative   or   Response   with   the   relative   sample)   arbitrary   other   peaks—A,   measured,   ratio  weight   of  factors   GC  common   Dietz   by   are   3%,   +   some  contain   his/her   sample   percentage   the

     Analysis   Normalization   implies,   is   area   the   be   to  method   must  analytes   must  analytes   must  analytes   conditions   a   if   identified  been   standards).   Normalization   available,   are   obtain   to   the   in   an   given   the   and   two   calculated,   the   is   response   most   work   values   may   determine   unknown   Then,



     Quantitative   Area   name   the   As   which  percent   analyte,  known   is   A,  where   For   this   All   *   All   *   All   *   three  These   useful   often   not   have   preparing   Area   standards   If   standards   the   be  analyte   an   is  factor f,   standard   the   of   the   of  areas   respectively—are   is   f,,  known,   w,/w,  where   Relative   lished   the   for   early   an   from   These  TCD.   columns   they   sh












     Analysis   obtained   the   deviation   working   Calibration   trace   in   one   only   invalidate   all   steps.   sample   of   the   calculations.   past   20   sample   representative   grinding   and   contamina-   it  used,   following   the   objectives   short   etc.   special   can   task   under   the   integra-   there   if   as   such   How-   peaks,   be   will   proceeding   accuracy.


     Quantitative   have   standard   one   the   or   step.   accuracy   high  accuracy.   is   step   can   to   paid   sampling,   detection   and   the   in   and  sampling   is   as:  techniques   concentrating,   and   chapter)   is   begun.   is   out   some   levels,  noise   detector,   Chapter   Of   2.   data.   This   the   area   electronic   especially   run,   the   reproducibility.   overlapping   data   all   briefly,   of  higher




     and   both  While   relative   analyst   calibration   obtaining   yield   chromatography   any   in   be   must   following:  (chromatography),   integration,   integration   usually   involved.   that  sample   such   extracting,   losses  avoid   in   this   processing   carried   be   treatises;   peaks,   low   the   of   in   digital   of   today’s   method,   during   by   follow,   that   discussed   capable
     Qualitative   analysts.   smaller   a   the   better   the   is   for  factor   precision   Measurements   gas   by   occur   that   attention   so   the  include   area   instrumentation   and   error   are   are   small   a   include   diluting,   taken   to   later   sample   should   chromatographic   symmetrical   range  linear   presented   to  signal  ways—integration   height.   With   preferred   conditions   injection  sample   less





           different   chemist   has   B   be   to   procedures   limiting   the   and  careful   Making   separation   Errors   analysis,   usually   separation   including   peak   GC   of   matrices   dirty   get   to   is   preparation   can   filtering,   care   be   must   (discussed   sample  before   separation   other   peaks,   the   in   systems   are   analog   the   two   of   peak   the   area   the   is   chromatographic   rate,   or



           two   X,   considered   quantitative   often   in   analysis,   procedure.   analysis   workup,   GC   in   sources   if   objective   step   standard   the   and   all   sizes   data   of   either   of   peak   flow   measurements   baselines.   quantitative   least   and

           by   value,   system.   all   is   calibration   Avoided   chromatographic   an   analysis   advances   especially   the   Sample   dissolving,   each   to   chromatographic   this   of   sample   and   conversion   by   in   areas.   Quantitative   simple
           obtained   average   therefore   better   in   step   and   Good   be   quantitative   total   the   in   steps   and   data   major   sampling,   whole.   In   internal   added   in   resolution   times,   analysis   the   measurement   computers,   changes   temperature,   height   sloping   peak   as   of   of   most



          data   is   the   One   essential,   analysis.   to   in   best   The   preparation   major   the   preparation,   the   crushing,   derivatizing.   If   an   be   gas   The   given   good   Data   is   accomplished   or   and   be   peak   and   methods   the
    134   of   same   and   with   is   Errors   a   In   step   the   analyte,   With   years,   In   of   and   tion.   should   advice   are:   analysis   interest   be   peaks   tors   may   column   ever,   noise,   presented   Methods   Five   from
   144   145   146   147   148   149   150   151   152   153   154