An Organic Solvent-Free and Space-Saving Method for Quantifying Cyromazine and Its Metabolite, Melamine, in Cow’s Milk

The author described an organic solvent-free, rapid, simple, and space-saving method of sample
preparation followed by HPLC coupled photo-diode array (PDA) detector for simultaneous
quantification of cyromazine (CYR) and its metabolite, melamine (MEL), in milk. The HPLC-PDA was
performed on an Inertsil® HILIC column with an isocratic aqueous mobile phase. Analytes were
extracted from the sample using water, and purified by Mono-Spin®-C18, a centrifugal monolithic silica
spin mini-columns, and quantified within 20 min. The method, performed under 100% aqueous
conditions, obtained average recoveries for CYR and MEL in the range of 93.2%-99.1% with relative
standard deviations ≤ 2.8%. The quantification limits were 8.5 ng/mL for CYR and 10 ng/mL for MEL,
respectively. No organic solvents were used at any stage of the analysis.