A diethylammonio-propylsulfate amphoteric ionic resin was synthesized and employed as the stationary phase for high-performance liquid chromatography-mass spectrometry (LC-MS) separation and detection of amino acids. The influence of experimental conditions such as mobile phase composition, column length and temperature upon the amino acid separations was evaluated. However, temperature, addition of water-miscible organic solvent to the mobile phase and mobile phase gradients were not effective at improving the separations. In contrast, the use of an unbuffered pure water mobile phase proved successful for the separation and detection of amino acids. The observed order of elution seems to parallel the isoelectric points of the respective amino acids and suggests that this diethylammonio-propylsulfate stationary phase column functions as an amphoteric ion-exchanger. Under optimized chromatographic conditions, the detection limits for the amino acids were in range of 0.07-0.44 pmol (pico-mole). The method was also successfully applied for the analysis of an actual commercial sample.

中文翻译：

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高效液相色谱-质谱法分离和检测氨基酸的二乙基铵基-丙基硫酸盐两性离子柱的合成和评价。

合成了二乙基氨基丙基硫酸盐两性离子树脂，并将其用作固定相，用于高效液相色谱-质谱（LC-MS）分离和氨基酸检测。评估了实验条件（如流动相组成，色谱柱长度和温度）对氨基酸分离的影响。但是，温度，与水混溶的有机溶剂添加到流动相中和流动相梯度对改善分离效果无效。相反，事实证明，使用无缓冲纯水流动相可成功分离和检测氨基酸。观察到的洗脱顺序似乎与各个氨基酸的等电点平行，这表明该二乙基氨基丙基硫酸盐固定相色谱柱可作为两性离子交换剂。在优化的色谱条件下，氨基酸的检出限为0.07-0.44 pmol（皮摩尔）。该方法也成功地用于实际商业样品的分析。