HIGH PERFORMANCE METAL CHELATE INTERACTION CHROMATOGRAPHY

开发了一种能够络合过渡金属离子的二乙烯三胺功能固定相，并对其在HPLC分离中的应用进行了评价。合成过程包括从醋酸缓冲水溶液中蒸发三甲氧基硅丙基单体并在200℃下衍生。C和0.55 torr。在100埃，550 m²/g二氧化硅上获得了3.0 mol /m²的可重复表面覆盖率。采用正面洗脱法分别在分析柱上加载Cu（II）、Ni（II）和Zn(II)；突破体积与原子吸收分光光度法测定的金属吸收量吻合良好。采用缓冲水-有机流动相分离磺胺类抗菌剂，包括磺胺嘧啶、磺胺噻唑、磺胺嘧啶和磺胺吡啶。建立了一个经验保留表达式，将色谱保留与：a)酸性磺酰胺功能与阳离子固定相的静电相互作用，b)涉及溶质的杂环芳香族取代基的仲金属配体络合以及c)相对疏水溶质在流动相中的增溶有关。保留率与有机改性剂和缓冲液的浓度成反比，通常与洗脱液的pH成正比。pH为7.3的磷酸盐缓冲液和50%甲醇的洗脱液可以有效地减少静电相互作用，同时允许基于金属配体相互作用的保留。这项工作是1991年6月发表的博士论文《静电和金属相互作用色谱法的磺胺类》的主题。

A diethylenetriamine functional stationary phase, capable of complexing transition metal ions, was developed and evaluated for use in HPLC separations. Synthesis involved evaporation of the trimethoxysilylpropyl-monomer from acetate buffered aqueous solution and derivatization at 200?C and 0.55 torr. Reproducible surface coverages of 3.0 moles/m-squared were obtained on 100-angstrom, 550 m-squared/g silica. Analytical columns were loaded with Cu(II), Ni(II) and Zn(II) by frontal elution process; breakthrough volumes corresponded well with metal uptake determined by atomic absorption spectrophotometry. Buffered aqueous-organic mobile phases were used for separations of sulfonamide antimicrobials that included sulfa- diazine, sulfa-thiazole, sulfa-merazine and sulfa-pyridine. An empirical retention expression was developed that related chromatographic retention to: a) electrostatic interaction of the acidic sulfonamide function with the cationic stationary phase, b) secondary metal-ligand complexations involving the heterocyclic aromatic substituents of the solutes and c) solubilization of the relatively hydrophobic solutes in the mobile phase. Retentions were inversely proportional to concentrations of organic modifier and buffer and were generally directly proportional to eluent pH. An eluent of pH 7.3 phosphate buffer and 50% methanol was effective in minimizing electrostatic interactions while allowing retention based on metal-ligand interactions. This work was the topic of a Ph.D. dissertation, entitled "Electrostatic and Metal Interaction Chromatography of Sulfonamides" that was defended and accepted in June, 1991.