Determination of melamine in foods by solid phase extraction-high performance liquid chromatography.

Objective To establish a solid phase extraction(SPE)-high performance liquid chromatography(HPLC)method for determination of melamine in foods. Methods Melamine in sample was extracted with extractive agent. After centrifugation, the supernatant fluid was purified by Waters Oasis MCX cartridge,and detected with HPLC method. Chromatographic column of TIANHE C18(250 mm×4.6 mm,5 μm) was used at 35 ℃ and mobile phase was water(containing 0.01 mol/L 1-hexanesulfonic acid sodium salt and 0.01 mol/L citric acid)∶ acetonitrile = 94∶6 (V∶V) at a flow rate of 1.0 ml/min. Injection volume was 20 μl. Results In the range of 0.80 to 80.0 mg/L, the regression equation was y=84.64 x-6.127 1 with the correlation coefficient of 0.999 98. The detection limit of melamine in foods was 0.5 mg/kg. The average rates of recovery were 88.0%-96.0% and the relative standard deviation was less than 5%. Conclusion The method established in the present paper is applicable to determination of melamine in foods with good precision,accuracy and sensitivity.