Simple extraction method for preservatives with small amount of solvent sorbic acid, dehydroacetic acid, benzoic acid and p-hydroxy benzoic acid esters.

Extraction method for sorbic acid (SOA), dehydroacetic acid (DHA), benzoic acid (BA) and p-hydroxy benzoic acid-esters (PHBAs) with 0.5 ml of n-butyl acetate (AcoBu), compared with the official extraction procedure, was cheep, fast and simple. Proper quantity (3-15 μg of SOA, 5-25 μg of DHA, BA and PHBAs determined by UV absorption of the distillate) of the distillate of food or 1 g of soft drinks was added to the test tube containing 0.1 ml of 10% of HCl and 3 g of NaCl. The sample was made up to 10 ml with water, 0.5 ml of 90 ppm n-tridecanoic acid-AcoBu solution (in the case of PHBAs, AcoBu was used) was added to the tube, and the tube was shaken vigorously. Upper layer was applied to GC. The recovery rates of the preservatives from the distillates of foods and from soft drinks were 95-102%. The results of marketed foods by our method were almost the same as the results by the official method.