Characterization of terrestrial dissolved organic matter fractionated by pH and polarity and their biological effects on plant growth

Chemical and Biological Technologies in Agriculture

Table 3 Average (by number and magnitude-weighted) mass spectral characteristics for each sample

Sample	O/C		H/C		DBE		DBE/C		%CHO		%CHON		%CHOS
Sample	num	mag	num	mag	num	mag	num	mag	num	mag	num	mag	num	mag
Whole	0.58	0.61	0.91	0.87	12.9	12.9	0.60	0.62	69%	87%	17%	8%	13%	5%
Acid insoluble	0.37	0.37	0.95	0.95	13.2	12.9	0.57	0.57	82%	87%	16%	11%	2%	2%
Acid soluble	0.57	0.60	0.94	0.91	12.5	12.5	0.58	0.60	70%	87%	19%	9%	11%	4%
C18 Fil:Ret 100:0	0.64	0.67	0.91	0.89	11.7	11.6	0.61	0.61	64%	84%	21%	9%	15%	7%
C18 Fil:Ret 75:25	0.57	0.60	0.94	0.90	12.3	12.3	0.58	0.60	73%	88%	18%	8%	9%	3%
C18 Fil:Ret 50:50	0.53	0.55	0.96	0.94	12.4	12.4	0.57	0.58	76%	90%	17%	7%	7%	2%
C18 Fil:Ret 25:75	0.51	0.51	0.97	0.96	12.8	12.7	0.56	0.57	75%	91%	17%	7%	8%	2%
C18 Fil:Ret 0:100	0.45	0.46	0.96	0.97	14.1	13.6	0.56	0.56	75%	91%	18%	7%	6%	2%

DBE (double bond equivalents) = (2c + 2 + n + p - h)/2 for any formula C_cH_hO_oN_nS_sP_p
DBE/C: double bond equivalents normalized to the number of carbon atoms in the formula
num indicates that the value given in number-averaged
mag indicates that the value given in magnitude-weighted
The van Krevelen diagrams are shown in Figure 5.