Determination of Formaldehyde in Milk and Dairy Products by High Performance Liquid Chromatography
A high performance liquid chromatographic(HPLC)method was developed for the determination of formaldehyde in milk and dairy products.The test samples were derivatized with 2,4-dinitrophenylhydrazine solution-sodium acetate buffer solution(pH=5),extracted by sonication for 10min,placed in a constant temperature shaker at 60℃and shaken at 150 r/min for 1 h to convert the formaldehyde to the corresponding stable formaldehyde-2,4-dinitrophenylhydrazone.The generated product was separated on a C18 column with the mobile phase of acetonitrile-water(60∶40,V∶V),detected by UV detector at 365 nm detection wavelength,and quantified by external standard method.The results showed that formaldehyde had a good linear relationship in the concentration range of 0 μg/mL-5 μg/mL with a correlation coefficient of 0.999.The relative standard deviations(RSDs)of formaldehyde in milk powder,liquid milk and yogurt at the three spiked levels were 0.46%~2.67%,0.91%~3.86%and 1.93%~3.11%,respectively,and the recoveries of formaldehyde in milk powder,liquid milk and yogurt at the three spiked levels were 90.2%~91.7%,98.5%~101%and 98.0%~101%,respectively.The test method is simple,rapid,accurate and reproducible,and provides a method for the determination of formaldehyde content in milk and dairy products.
high performance liquid chromatographymilk and dairy productsformaldehyde