Organic carbon and nitrogen in fine soil fractions after treatment with hydrogen peroxide

We tested the effectiveness of H2O2 on removal of organic carbon and total nitrogen for mineral soil fractions < 20 mum of agricultural soils. OC contents of the untreated and treated samples were in a range of 29-84 and of 3-10 mg OC g(-1), respectively (N: 3-10 and 1-3 mg N g(-1)). Losses of OC were 89.5 +/- 2.8% and significantly higher than losses of N (79.6 +/- 5.3%; P < 0.001). OC contents after H2O2 treatment correlated significantly with initial OC contents (P < 0.01). The CPMAS C-13 NMR spectrum obtained from one sample showed a preferential loss of O-alkyl C, aromatic C and carboxyl C and a relative increase of alkyl C. (C) 2001 Elsevier Science Ltd. All rights reserved.