Estimation of Acyl Derivatives

When the substance under estimation is either an acyl derivative of an alcohol or phenol which is not affected by alkali and air, or an acyl derivative of a volatile base, the estimation may be carried out as for esters with alcoholic potash (p. 509), any free base being removed by distillation before titrating the excess of alkali. 

When alcoholic potash cannot be employed, the acyl derivative may be hydrolysed with benzene sulphonic acid (see above) or phosphoric acid, provided that the acid produced is volatile in steam benzene sulphonic acid is a stronger acid than phosphoric. 

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