A microscale method is described for the preparation of the pentafluorobenzyl ester of an organic acid, indole-3-acetic acid, using α-bromopentafluorotoluene as the esterifying agent and the volatile base, N-ethyl-piperidine. The resultant reaction mixture may be used directly for gas chromatography employing an electron-capture detector, or greater sensitivity and selectivity can be attained by negative ion chemical-ionization gas chromatography-mass spectrometry. The method is applicable to assay of indole-3-acetic acid in resinous plant material such as olive leaves.
Bibliographical noteFunding Information:
Pulsed positive/negative-ion MS data were provided by Dr. R. W. K. Chapman, Finnigan Corporation, 1383 Piccard Dr., Suite 100, Rockville, MD 20850, U.S.A., and Ms. A. Schulze, Ms. P. J. Hall and Ms. S. D. Cohen assisted with GC-SIM-MS. This work was supported by U.S.-Israel Binational Agricultural Research and Development grant I-5-79 to E.E. and to Dr. R. S. Bandurski and, in part, by National Science Foundation grant PCM 79-04637 and National Aeronautics and Space Administration grant NAGW-97, ORD25796 to Dr. R. S. Bandurki. This is contribution No. E-306, 1980 series, from the Agricultural Research Organization, ‘The Volcani Center, Bet Dagan, Israel and is Journal article 9723 from the Michigan Agricultural Experiment Station.