01221naa a2200241 a 450000100080000000500110000800800410001910000200006024501380008026000090021830000170022752003640024465000210060865000090062965300190063865300150065765300080067265300260068070000200070670000220072670000190074877302120076710246872008-05-07       2002    bl ---       0--  u    #d1 aFERREIRA, J. A.  aHydrophobic sites in humic acid as detected by ESR of spin-label stearic acid, 13C NMR of labeled oleic acid and pyrene fluorescence.  c2002  ap. 388-391.   aThe present study sought hydrophobic markers to evaluate hydrophobic interactions with HAs at different pH values and for various reaction study sought hydrophobic were: the spin-label probe 5-SASL (N-oxy-4',4'-dimethyl oxazolidine derivative of 5-ketostearic acid0, detectable by ESR; [1-13C] oleic acid (OA), detectable by NMR; and the fluorescent probe PY.  ahumic substances  aSolo  aÁcido húmico  aHumic acid  aNMR  aSubstâncias húmicas1 aMARTIN-NETO, L.1 aNASCIMENTO, O. R.1 aCOLNAGO, L. A.  tIn: INTERNATIONAL HUMIC SUBSTANCES SOCIETY-IHSS; ANNIVERSARY CONFERENCE, 20., 2002, Boston. IHSS 2002: humic substances: nature's most versatile materials: proceedings. Boston: Northeastern University, 2002.