In 2007, pet foods imported from China caused serious illnesses or deaths in a large number of cats and dogs. US Food and Drug Administration reported that melamine was found in the pet foods as well as in urine of affected animals. Moreover, in 2008, milk and infant formula adulterated with melamine caused kidney stones and other renal failure, especially among young children.
Since melamine is very hydrophilic compound, it is difficult to retain and analyze melamine using ODS columns. It is also undesirable to use ion-pair reagents because the sensitivity is reduced in LC/MS/MS detection.
In this note, Inertsil HILIC (hydrophilic interaction chromatography) was used as a separation column. Melamine was successfully retained and determined with good linearity.