Measurement of Total Free Iron in Soils by H₂S Chemisorption and Comparison with the Citrate Bicarbonate Dithionite Method

Table 2

The sulfur capacities of the Loupi soil at various temperatures under the experimental condition of 50% H₂ and 1% H₂S with balanced N₂.

Temperature	Breakthrough time (min)	Sulfur content (%)	Sulfur content by EA (%)	Sulfur balance; (%)	Estimated total free iron; (Fe2O3%)
673 K	20	0.22	0.23	95.65	2.05
723 K	26	1.13	1.12	100.89	2.66
773 K	32	1.39	1.37	101.46	3.28
823 K	30	1.31	1.30	100.76	3.07
873 K	21	0.91	0.92	98.91	2.15
923 K	19	0.83	0.84	98.81	1.95

CBD-Fe: 4.28 (Fe₂O₃%).