derivatization To the Question the Choice of a Derivatizing Agent for the Transfer of Methylphosphonic Acid and its O-alkils Ethers to Chromatographic Derivatives Authors: Kuzmina R. I., Uglanova V. Z., Denisov S. N., Denisov N. S. The products of the derivatization of methylphosphonic acid and its ethers were investigated by gas chromatography – mass spectrometry. The optimum conditions of the derivatization of higher-boiling organo- phosphorus compounds were described.