POST-CHROMATOGRAPHIC FIXED-CHARGE DERIVATIZATION FOR THE ANALYSIS OF HYDROXYL-CONTAINING COMPOUNDS BY A COMBINATION OF THIN-LAYER CHROMATOGRAPHY AND MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY ArticleBorisov R.S., Polovkov N.Y., Zaikin V.G., Esparza C.Journal of Chromatography A. Том 1560. 2018. С. 97-103