Hydroxylamine hydrochloride-clay

Scheme 6.49 Transformation of arylaldehydes to nitriles by hydroxylamine hydrochloride-clay.

Scheme 8.84. Transformation of a laldehydes to nitriles by use of hydroxylamine hydrochloride-clay.

The partial leach protocol used a 2-h leach, using 40 ml of 0.25 M hydroxylamine hydrochloride in 0.1 M HCI at 60°C, on 1 g of the <63- j.m fraction (Cameron et al. 2004). This hydroxylamine leach is designed to dissolve secondary iron and manganese oxides. This relatively aggressive leach protocol will also dissolve phosphatic, calcareous and amorphous clay components, and will likely desorb any ions weakly bonded to other components. 

To extract different forms of Ee, the clay fractions from the fine earth of bulk, LAR and TAR were dispersed in NaOH at pH 8.5 and treated with acidic (pH 3) NH4-oxalate (Blakemore et al., 1981), citrate-bicarbonate-dithionite (CBD) (Mehra and Jackson, 1960) and 0.1 M hydroxylamine hydrochloride (HAHC) (Chao, 1972). The Ee extracted was measured by atomic absorption with a Perkin-Elmer llOOB spectrophotometer. 

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