Simultaneous determination of melamine and benzoquanamine in aqueous food simulants of food contact materials by high performance liquid chromatography

A new analytical method based on high performance liquid chromatography(HPLC) technique was developed for the simultaneous determination of melamine and benzoquanamine in aqueous food simulants of food contact materials. According to the type of the contacted food,the samples were extracted by water,3%(w/v) acetic acid aqueous solution,4%(v/v) acetic acid aqueous solution,10%(v/v) ethanol aqueous solution,20%(v/v) ethanol aqueous solution or 50%(v/v) ethanol aqueous solution. The extracted solutions were injected in HPLC column before the penetration through a 0.45 m microporous membrane. The separation was performed on a strong cation exchange and reversed phase C18mixed packing column(1∶4,by mixing ratio) at 35℃ and with acetonitrile-20mmol/L ammonium acetate buffer solution(pH=3.0)(40∶60,v/v) as the mobile phase at a flow rate of 0.2mL/min. The detection was performed at UV 240nm. Under the optimum conditions,the linear range was from 0.2 to 20.0mg/L with the linear correlation coefficients of 0.9997~0.9999. The limits of quantification(S/N≥10)were 0.015~0.033mg/dm2. The mean recoveries were 80.0%~103.3% in spiked level of 0.025~0.70mg/dm2with the relative standard deviation(n=6) 0.5%~4.0%. This method is simple,rapid and suitable for the simultaneous determination of melamine and benzoquanamine in aqueous food simulants of food contact materials.