D'Orazio G, Aturki Z, Cristalli M, Quaglia M G, Fanali S
Institute of Chemical Methodologies, Consiglio Nazionale delle Ricerche, Area della Ricerca di Roma I, Rome, Italy.
J Chromatogr A. 2005 Jul 15;1081(1):105-13. doi: 10.1016/j.chroma.2005.02.025.
In this paper we studied the potentiality of nano-liquid chromatography (nano-LC) for the enantiomeric resolution of both basic and acidic compounds of pharmaceutical interest using a vancomycin modified silica stationary phase. Experiments were carried out in a fused silica capillary of 75 microm I.D. packed with chiral modified silica particles of 5 microm diameter, the detection, was done on-line at 195 nm. Enantiomeric resolution of alprenolol, atenolol, metoprolol, oxprenolol, pindolol, propranolol (basic compounds) and some acidic analytes, namely 2-[(5'-benzoyl-2'-hydroxy)phenyl]propionic acid (DF1738Y), 2-[(4'-benzoyloxy-2'-hydroxy)phenyl]propionic acid (DF1770Y), ketoprofen, indoprofen and suprofen was studied by nano-LC utilizing mobile phases containing methanol-acetonitrile-ammonium formate or acetate. The effect of mobile phase composition (buffer type and concentration, organic modifier type and concentration) on chiral resolution (Rs), retention factor (k) and retention time (tR) was also investigated. Good enantiomeric resolution was achieved for basic compounds utilizing the mobile phase containing 90% (MeCN-MeOH)/5% water/5% of 100 mM ammonium acetate pH 4.5. Acidic compounds such as DF1738Y and DF1770Y were better resolved at lower pH 3.5 while ketoprofen, indoprofen and suprofen exhibited the highest resolution at pH 4.5; in this case the mobile phase contained MeOH or MeCN (90%), 5% buffer and 5% of water. The nano-LC method was validated using R-(+)-propranolol as an internal standard finding good repeatability, detection limit, correlation coefficient and recovery and applied to the assay of a pharmaceutical formulation containing a racemic mixture of metoprolol.
在本文中，我们研究了使用万古霉素修饰的硅胶固定相，采用纳米液相色谱法（nano-LC）对具有药学意义的碱性和酸性化合物进行对映体拆分的潜力。实验在内径75微米的熔融石英毛细管中进行，填充有直径5微米的手性修饰硅胶颗粒，检测在195纳米处在线进行。使用含有甲醇-乙腈-甲酸铵或乙酸铵的流动相，通过纳米液相色谱法研究了阿普洛尔、阿替洛尔、美托洛尔、氧烯洛尔、吲哚洛尔、普萘洛尔（碱性化合物）以及一些酸性分析物，即2-[(5'-苯甲酰基-2'-羟基)phenyl]丙酸（DF1738Y）、2-[(4'-苯甲酰氧基-2'-羟基)phenyl]丙酸（DF1770Y）、酮洛芬、吲哚洛芬和舒洛芬的对映体拆分情况。还研究了流动相组成（缓冲液类型和浓度、有机改性剂类型和浓度）对手性拆分度（Rs）、保留因子（k）和保留时间（tR）的影响。使用含有90%（乙腈-甲醇）/5%水/5% 100 mM乙酸铵pH 4.5的流动相，碱性化合物实现了良好的对映体拆分。DF1738Y和DF1770Y等酸性化合物在较低pH 3.5时拆分效果更好，而酮洛芬、吲哚洛芬和舒洛芬在pH 4.5时表现出最高的拆分度；在这种情况下，流动相含有甲醇或乙腈（90%）、5%缓冲液和5%水。以R-(+)-普萘洛尔为内标对纳米液相色谱法进行了验证，结果显示具有良好的重复性、检测限、相关系数和回收率，并将其应用于含有美托洛尔外消旋混合物的药物制剂的测定。
