Results and Discussion
Melamine and Cyanuric Acid
were separated using a normal
phase gradient on a Hydrophilic
Interaction Chromatography (HILIC)
column. Periods were adjusted to
allow detection in negative and positive
polarity with highest sensitivity. An
example chromatogram is given in
Figure 1. Linearity and reproducibility
of the developed method was studied
by 5 replicate injections at each
concentration level. The example
calibration line of Melamine given in
Figure 2 highlights the linear range
of 3 orders of magnitude and the
reproducibility and accuracy of this
method. Limits of detection were
found below 1μg/kg for Melamine
and Cyanuric Acid. Figure 3 shows a
chromatogram with Signal-to-Noise
ratios and detected MRM transitions
used for confirmation.
Several pet food samples were extracted
and analyzed for both targeted analytes.
Examples of a blank and a contaminated
cat food sample are given in Figure 4.