不同品种沙蚕中氨基酸含量的HPLC测定及多元统计分析

目的:测定不同品种沙蚕中15种氨基酸含量并进行多元统计分析。方法:采用酸水解法制备水解氨基酸样品溶液,以异硫氰酸苯酯为衍生化试剂衍生后进行HPLC分析。采用CAPCELL PAK C₁₈色谱柱(4.6 mm×250 mm, 5μm),以0.1 mol·L^-1醋酸钠溶液(pH 6.5)-乙腈(93:7)为流动相A,乙腈-水(8:2)为流动相B,梯度洗脱,流速1.0 mL·min^-1,柱温40℃,检测波长254 nm,进样量2μL。采用主成分分析法对不同品种沙蚕中15种氨基酸相对含量进行分析。结果:15种氨基酸在一定浓度范围内呈良好线性关系,线性相关系数r值均大于0.9996,加样回收率(n=6)为96.1%~101.5%,氨基酸衍生溶液在12 h内稳定;氨基酸相对含量的主成分分析可以达到降维的目的,各品种沙蚕样品得到较好的区分。结论:所建立的条件方法可靠,精密度和重复性良好,可用于沙蚕中水解氨基酸含量的测定,主成分分析可用于揭示沙蚕的特征氨基酸,为沙蚕品质特征评价提供依据。

Objective:To determine the content of 15 different amino acids in different kinds of nereids and analyze the data by multivariate statistical analysis. Methods:Acid hydrolysis method was used for the extraction of hydrolytic amino acids, and derived with phenyl isothiocyanate(PITC). HPLC was performed on a CAPCELL PAK C 18(4.6 mm×250 mm, 5μm)column with gradient elution.The mobile phase consisted of 0.1 mol·L^-1 sodium acetate buffer solution(pH 6.5)-acetonitrile(93:7)(A)and acetonitrile-water(8:2)(B)with a flow rate of 1.0 mL·min^-1, the detection wavelength was 254 nm, the column temperature was 40℃, and the injection volume was 2μL. The principal component analysis(PCA)was applied to the relative amount of amino acids in different kinds of nereids. Results:The response was linear for 15 amino acids with a correlation coefficient r> 0.9996. The average recoveries(n=6)were 96.1%-101.5%. Amino acids derivative solution remained stable in 12 hours. Dimension reduction was achieved successfully by PCA and this statistical method was useful for the distinction of nereid. Conclusion:The established method is reliable with good accuracy and repeatability, and is useful for the determination of amino acids in nereid. PCA can be used to reveal the characteristic amino acids, and thus provides a reference for the quality evaluation of nereid.