Simultaneous determination of melamine and related compounds by capillary zone electrophoresis

A simple, rapid and accurate method for the simultaneous determination of melamine and related compounds (ammeline, ammelide and cyanuric acid) by capillary zone electrophoresis with diode array detection (CZE–DAD) was developed and successfully applied in egg, dairy products and pet feed. Real samples were extracted with acetonitrile/water/diethylamine (80/18/2, v/v/v) and analyzed by CZE method directly after centrifuging and filtering. Separation was performed by CZE using 40 mM disodium hydrogen phosphate buffer (pH 9.0) as running buffer, an applied voltage of +30 kV, and UV detection at 214 nm. Four targets were separated completely within 10 min. The optimized method demonstrated good performance concerning linearity (r ⩾ 0.9964), precision (⩽4%), accuracy (82.2–101.6%), and enough sensitivity. And the proposed method was proved to have the merits of good separation, easy operation, short analysis time and low cost.