Biomaterial Database

Automated analysis of benzoic acid in food: colorimetric determination after continuous volatilization. 1975

H W van Gend

A method is developed to determine benzoic acid colorimetrically with the Technicon AutoAnalyzer. After a selective hydroxylation of benzoic acid by means of hydrogen peroxide and a catalyzing reagent consisting of a buffered solution of cupric ion, catechol and sorbic acid, a reaction follows with 4-aminoantipyrine. The reddish brown reaction product formed is measured at 505 nm. In a distillation unit benzoic acid is continuously separated from the acidified sample stream by volatilization into a stream of nitrogen. With simple manual treatments solid samples can be analysed. Possible interferences caused by naturally present or added compounds in food were investigated. The precision of the method is very good. The coefficient of variation is 0.6% at 50 mug/ml. For several products the recovery was determined with a mean of 98.4%. The working range covered is 0--100 mug benzoic acid/ml.

UI	MeSH Term	Description	Entries
D003124	Colorimetry	Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D005504	Food Analysis	Measurement and evaluation of the components of substances to be taken as FOOD.	Analysis, Food,Analyses, Food,Food Analyses
D005506	Food Contamination	The presence in food of harmful, unpalatable, or otherwise objectionable foreign substances, e.g. chemicals, microorganisms or diluents, before, during, or after processing or storage.	Food Adulteration,Adulteration, Food,Adulterations, Food,Contamination, Food,Contaminations, Food,Food Adulterations,Food Contaminations
D005519	Food Preservation	Procedures or techniques used to keep food from spoiling.	Preservation, Food
D001565	Benzoates	Derivatives of BENZOIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxybenzene structure.	Benzoate,Benzoic Acids,Acids, Benzoic