Spectrophotometric determination of phenol by the 4-aminoantipyrine method after steam distillation in a semimicro kjeldahl apparatus in the presence of a large amount of sodium chloride

Phenol is quantified rapidly and accurately by the 4-aminoantipyrine spectrophotometric method after adding 15 g of sodium chloride to a 25-ml sample and distilling in a Semimicro steam distillation apparatus of the Pregl—Parnas—Wagner type. The large amount of sodium chloride provides a saturated solution of the salt during the course of the distillation and causes most of the phenol to be contained in the first few milliliters of distillate. The method has been used to quantify up to 25 mg of phenol per 25 ml.