HPLC Determination of Formaldehyde in Foodstuffs by Extraction with Derivative Solution

HPLC was applied to the determination of formaldehyde in some foodstuffs. The formaldehyde in sample was extract with a mixture of 2,4-dinitro-phenylhydazine (dissolved in acetonitrile) and phosphate buffer solution of pH 5 (1+1) as derivatizing solution, and separated on Agilent C18 column (4.6 mm×250 mm, 5 μm). A mixture of methanol and water mixed in the ratio of 70 to 30 (by volume) was used as mobile phase. Values of limit of determination (10S/N) found was 5.0 mg·kg-1. Using samples of fresh mushroom, fresh squid, milk powder and flour as matrixes, tests for recovery were made by standard addition method at 3 concentration levels of 5.0, 10.0 and 20.0 mg·kg-1, and the results obtained were in the range of 73.3%-97.7%, with values of RSD′s (n=6) in the range of 1.4%-5.0%.