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Determination of ascorbic acid in honey samples was performed by high performance liquid chromatography (HPLC) with UV detection at 254 nm. The separation was performed using a C-18-ODS column with a mobile phase consisting of a mixture of 15% methanol and 85% water, adjusted to pH 2.5 with metaphosphoric acid. The mobile phase was pumped at a flow rate of 0.9 mL/min. The retention time for ascorbic acid was found to be 5.1 minutes. The method is simple, fast, sensitive, and reproducible. The recovery of ascorbic acid is over 90% by the standard addition method.

A method for the rapid determination of the hydroxyl value of oils, fats and related products is described. The method uses toluene-p-sulphonic acid as a catalyst and this allows the sample, dissolved in toluene, to be acetylated in 10 min at room temperature. The fatty acid anhydrides formed during the acetylation are decomposed with aqueous sodium hydroxide and tert-butanol, and are then titrated with hydrochloric acid. The addition of an aliquot of the sample to the blank after the decomposition of the acetic anhydride reduces the number of titrations required to two.

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