毛细管电泳间接紫外法分离分析海藻和酱油中游离氨基酸方法研究

Separation and analysis of free amino acids in seaweed and soy sauce by capillary electrophoresis with indirect ultraviolet detection

目的建立1种快速检测海藻和酱油中游离氨基酸的毛细管电泳间接紫外法分离分析方法。方法在分离电压为-20kV,毛细管柱温25℃的条件下,40 mmol/L三羟甲基氨基甲烷(Tris)为分离缓冲液,20mmol/L烟酸为背景添加剂(NaOH调pH 11.00),质量体积分数0.015%的溴化己二甲铵(HDB)为电渗流(EOF)反转剂,考察分离缓冲液pH、浓度、HDB浓度、电压等参数对分离的影响,在最佳优化条件下13min内13种未衍生氨基酸得到基线分离。结果方法线性良好(r≥0.997 2),日内及日间精密度分别低于4.25%和7.41%,加标回收率为94.6%～105.5%。建立的方法成功应用于海藻和酱油中游离氨基酸的定性定量分析。结论结果表明,所开发的方法可用于快速测定不同样品中游离氨基酸的组成及含量,为海藻和酱油样品中游离氨基酸的快速检测奠定基础。

Objective A rapid analytical method for the determination of amino acids in seaweed and soy sauce was developed by capillary electrophoresis(CE)with indirect ultraviolet detection.Methods The experiments were set up at a separation voltage of-20 kV and a capillary column temperature of 25℃.20 mmol·L-1 nicotinic acid and 40 mmol·L-1 tris(hydroxymethyl)aminomethane(Tris)(NaOH adjusts pH 11.00)were added as background and electrolyte buffer,respectively.Meanwhile,the mass fraction of 0.015% hexadimethrine bromide(HDB)was applied as electro-osmotic flow(EOF)modifier.The effects of separation buffer pH,ionic strength,HDB concentration,and voltage on separation were investigated.Under the optical conditions,13 underivatized amino acids achieved baseline separation in 13 minutes.Results The proposed method provided a good linearity(r≥0.997 2),inter-day and intra-day precision were lower than 4.25%and 7.41%respectively,and the recovery was in the range of 94.6%~105.5%.The method has been successfully applied to the detection and analysis of amino acids in seaweed and soy sauce.Conclusion The results indicated the developed method could quickly determine the composition and content of free amino acids in different samples.The method offered a foundation for the rapid detection of free amino acids in seaweed and soy sauce.