It has been held by ~&CY &a CIIEMEII,
GUIFFIZIDA,
and I<r~~~~~~ that the response of the alkali flame (thermionic) detector is proportional to the amount of hetero-element introduced; other authors disagreed. This paper presents evidence to confirm this proportionality for both positive and negative modes of detector response, and describes its application to determine the percentage of various hetero-elements present in organic compounds. This determination is done by adding a suitable "standard" to an "unknown" compound and comparing their responses on both alkali flame and flame ionization detectors. For such calculations, pairs of model compounds were used which contained either P, N, or I for positive alkali flame response; or Cl, Br, or S for negative response. The accuracy of the results depends on the choice of a suitable standard and proper chromatographic conditions. The percent chlorine content of fifteen organochlorine compounds, for instance, was determined with a standard deviation of 3.6 Y&. IX TRODUCTION l Contribution from the Espcrimcnt Station Chemical Lnboratorics, Journal Scrics So. 7 I $3 ; supportccl lay the l~nvironmcntnl Tract Substnnccs Center. Columbia. No., U.S.A.