气相色谱-质谱法测定奶油饼干中三聚氰胺

Determination of melamine in cream biscuit by gas chromatography-mass spectrometry

目的：建立了气相色谱-质谱法测定奶油饼干中三聚氰胺含量的分析方法。方法：样品经乙酸-乙腈-水溶液超声提取,离心,滤液经混合型阳离子交换固相萃取柱净化,氮气吹干,硅烷化衍生,气相色谱-质谱测定,选择离子监测模式,外标法定量。结果：在0.01-5 mg/kg的范围内线性良好（r〉0.99）,在0.5-2.5 mg/kg的添加水平范围内,平均回收率为87%-102%,相对标准偏差（RSD）为3.4%-12.4%,检出限（LOD）为0.01 mg/kg。结论：结果表明：该方法简便、快速、灵敏、准确、低成本、耐用,适合奶油饼干中三聚氰胺确证和定量测定。

Objeetive：A gas chromatography - mass spectrometry method is presented for the quantitative determination and confirmation of melamine in cream biscuit. Methods：Cream biscuit was extracted with acetic acid acetonitrile water solution. An aliquot of the filtrate was cleaned up using mixed - mode cation exchange solid - phase extraction cartidges, evaporated to dryness and the residues was converted to trimethylsilyl derivatives. Analysis was performed using gas chromatography - mass detereetion in selected ion monitoring（SIM） mode, external standards were used for quantitative determination. Results：The linear range was from 0.01 to 5 mg/kg. The average recoveries were 87% - 102% and relative standard deviations were 3.4% - 12.4% in the spiked range of 0. 5 - 2.5 mg/kg. The limit of detection was 0. 01 mg/kg. Conclusion：The method is suitable for the quantitative determination and confirmation of melamine in cream biscuit.