Atomic emission spectroscopy coupled with capillary gas chromatography (GC) has been evaluated for molecular formula determination of several chlorinated and brominated compounds present in three environmental samples. Variations in elemental responses due to compound type, poor chromatographic resolution, and small signals relative to the background were all found to complicate molecular formula calculations. About 20% of the calculated molecular formulas presented in this paper agreed with theoretical values. For most applications, identifications based solely on GC coupled with theoretical values. For most applications, identifications based solely on GC coupled with atomic emission detection (AED) are not sufficiently accurate. However, the combination of elemental information derived form a GC‐AED analysis with complementary data obtained from other detection techniques results in a strong analytical tool for analyte identification.