“…Thus, it is not surprising that in the last decade the application of multidimensional NMR has grown exponentially (Simpson et al, 1997(Simpson et al, , 2001a(Simpson et al, ,c, 2002a(Simpson et al, , 2003aHaiber et al, 1999Haiber et al, , 2001aFan et al, 2000 ;Kingery et al, 2000 ;Knicker, 2000a ;Simpson, 2001 ;Hertkorn et al, 2002bHertkorn et al, , 2006Cook et al, 2003 ;Kaiser et al, 2003 ;Kim et al, 2003 ;Cardoza et al, 2004 ;Mao and Schmidt -Rohr, 2006 ). In 1989, the fi rst applications of multidimensional NMR were applied to humic substances (Buddrus et al, 1989 ). This study involved the application of 13 C detected J -resolved (J -Res) spectroscopy.…”