Fruit and vegetable products — Determination of benzoic acid content (benzoic acid contents greater than 200 mg per litre or per kilogram) — Molecular absorption spectrometric method
水果和蔬菜产品——苯甲酸含量的测定(苯甲酸含量大于每升或每千克200毫克)——分子吸收光谱法
The method consists in extracting the acid from an acidified test portion using diethyl ether, nitrating followed by reduction and Mohler's reaction modified with hydroxylaminehydrochloride, measuring the absorbance of the red complex obtained with a suitable spectrometer. For determining lower concentrations, see ISO 5518.