| 摘要 |
<p>A new method for determination of hydroxyl radicals in oxidation reactions, uses phthalic hydrazide to trap hydroxyl radicals with formation of a hydroxylated derivative, which at a later time can be oxidised with a developing agent and monitored by chemiluminescence. The reaction is useful for the determination of the progress of pulp bleaching using oxygen or hydrogen peroxide. In particular it monitors a reactive species, but does not require immediate determination of the chemiluminescence. The developing agent particularly contains peroxide anions, and may be a mixture of hydrogen peroxide and persulphate. The developer also contains carbonate to buffer at high pH and EDTA to sequester heavy metal cations. (Provisional Basic previously advised in week 9022).</p> |
