Gas chromatographic analysis of the thermally unstable dimethyl methylphosphonate carbanion via trimethylsilyl derivatization.

A sensitive gas chromatographic method was developed to monitor the reaction of lithium diisopropylamide (LDA) with dimethyl methylphosphonate (DMMP) to generate the phosphonate carbanion (DMMPA). Analysis of the DMMPA was complicated due to its thermal instability and lack of a chromophore. To overcome these problems, samples were derivatized with trimethylsilylchloride (TMSCI) to form DMMPA-TMS which was sufficiently volatile and thermally stable for GC analysis.