柱前衍生-高效液相色谱法测定保健食品中16种氨基酸的含量

Determination of 16 kinds of amino acids in health foods by high performance liquid chromatography with pre-column derivatization

目的建立柱前衍生-高效液相色谱法测定保健食品中16种氨基酸的含量。方法优化GB/T5009.124-2003的前处理方法,样品经稀释或置于顶空瓶中直接酸水解;并采用OPA/FMOC柱前衍生法,色谱柱为Thermo ODS Hypersil,以醋酸钠缓冲液（含三乙胺、四氢呋喃）和醋酸钠缓冲液（含乙腈、甲醇）为流动相进行梯度洗脱,在338 nm和262 nm检测波长下进行高效液相色谱法检测。结果 16种氨基酸在4-250μg/mL范围内呈现良好线性关系,在10μg/mL水平下加标回收率为85.8%-115.2%,RSD为0.1%-9.1%（n=6）,检出限在0.2-4.6 ng范围内。结论本方法操作简便、灵敏度高,可应用于实际样品的测定。

Objective To establish a method for determination of 16 kinds of amino acids in health foods by high performance liquid chromatography （HPLC） with pre-column derivatization. Methods By optimizing pretreatment and analytical method of GB/T 5009.124-2003, samples were diluted or direct acid hydrolyzed in headspace bottle, and the amino acids were determined by HPLC after pre-column derivatization with o-Phthalaldehyde （OPA）/9-fluorenylmethyl chloroformate （FMOC）. A Thermo ODS Hypersil column was used for separation with sodium acetate buffer solution （containing triethylamine and THF） and sodium acetate buffer solution （containing acetonitrile and methanol） as the mobile phase for gradient elution. Samples were detected by HPLC under the detection wavelengths of 338 nm and 262 nm. Results Sixteen kinds of amino acids presented good linear relationships in the concentration range of 4-250 μg/mL. The recoveries spiked at the level of 10 μg/mL were ranged in 85.8%-115.2% with RSDs of 0.1%-9.1% （n=6）, and the limits of detection were 0.2-4.6 ng. Conclusion This method is simple and sensitive, which can been used for the determination in practical sample.