Phosphorus content can be determined in the range of 0,000 5 % (m/m) to 0,05 % (m/m). As, Cr, Hf, Nb, Si, Ta, Ti, W interfere, but the interferences can be avoided. The principle is dissolution of a test portion in a mixture of nitric and hydrochloric acids, fuming with perchloric acid, removal of chromium, complexation of silicon, conversion of phosphorus to phosphovanadomolybdic acid, extraction of this compound.
Life cycle
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WITHDRAWN ISO 11400:1992 95.99
Withdrawal of Standard Dec 15, 2021
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