Determination of residual alkyl iodides and alkyl bromides as their corresponding alkyl chlorides in drug substances by headspace GC-FID.

Primary and secondary alkyl iodides and primary alkyl bromides were quickly and conveniently converted into their corresponding alkyl chlorides via S2 halide-halide substitution. The resultant alkyl chlorides simultaneously demonstrated increased volatility and stability paired with standard headspace GC-FID methodology. The derivatization was performed on both standard and sample alike and occurred during the headspace oven equilibration phase, eliminating the extra reaction step traditionally performed during many derivatization analyses.