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

Table 3

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

Temperature	Breakthrough time (min)	Sulfur capacity (%)	Sulfur capacity by EA (%)	Sulfur balance; (%)	Estimated total free iron; (Fe2O3%)
673 K	30	1.31	1.32	99.24	3.07
723 K	41	1.78	1.77	100.56	4.19
773 K	42	1.83	1.81	101.10	4.30
823 K	40	1.74	1.72	101.16	4.09
873 K	35	1.52	1.50	101.33	3.58
923 K	33	1.44	1.44	100.0	3.38

CBD-Fe: 4.28 (Fe₂O₃%).