NEW SUITABLE DEPROTONATING MATRICES FOR THE ANALYSIS OF CARBOXYLIC ACIDS AND SOME ACIDIC COMPOUNDS BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY IN NEGATIVE ION MODE Article Krivosheina M.S., Borisov R.S., Zhilyaev D.I., Matveeva M.D., Zaikin V.G. Rapid Communications in Mass Spectrometry. John Wiley and Sons Ltd. Vol. 35. 2021.