高效液相色谱-串联质谱法分析毛发中甲基苯丙胺和苯丙胺手性对映异构体

建立了高效液相色谱-串联质谱（HPLC-MS/MS）分析毛发中甲基苯丙胺与苯丙胺对映异构体的手性分离方法。采用SUPELCO Astec CHIROBIOTIC^® V2手性液相色谱柱,以甲醇-含0.1%（v/v）甲酸的20 mmol/L乙酸铵水溶液（99：1,v/v）为流动相进行手性分离。结果表明,甲醇高温水浴超声法能较好地提取苯丙胺类化合物,且峰形较好（拖尾因子>0.95）。S-（+）-甲基苯丙胺、R-（-）-甲基苯丙胺、S-（+）-苯丙胺和R-（-）-苯丙胺在15~300 ng/mg范围内线性关系良好,相关系数均大于0.99;甲基苯丙胺和苯丙胺的检出限分别为0.1 ng/mg和0.15 ng/mg,定量限分别为0.4 ng/mg和0.5 ng/mg;日内精密度均≤6.8%,日间精密度均≤11.4%。采用所建方法对50余嫌疑人毛发进行手性分析,检出单一S-（+）-甲基苯丙胺和S-（+）-苯丙胺的占70%,同时检出S-（+）-甲基苯丙胺、R-（-）-甲基苯丙胺、S-（+）-苯丙胺和R-（-）-苯丙胺的占18%。该法简单快速,精密度好,可为实际法医毒物鉴定案例中的毛发手性分析提供技术支持与科学依据。     

模拟移动床色谱分离制备手性农药甲霜灵的研究

利用自行组建的模拟移动床色谱(SMBC),在正相条件下,在自制的涂敷型纤维素-三(3,5-二甲基苯基氨基甲酸酯)手性固定相上成功制备出甲霜灵对映体,所制备的对映体纯度达到99%以上,与高效液相色谱法制备相比较,模拟移动床技术制备甲霜灵对映体的效率以及流动相的利用率均明显高于高效液相色谱法.     

手性金属-有机骨架材料[Cu(S-mal)(bpy)]n用于高效液相色谱拆分外消旋化合物

手性金属-有机骨架材料作为一种新型的多孔材料,在手性分离领域备受关注.以S-苹果酸和4,4'-联吡啶为配体与醋酸铜反应,通过溶剂热法合成了一种具有三维手性网状结构的手性金属-有机骨架材料[Cu（S-mal）（bpy）]_n.将其用作固定相制成高效液相色谱手性柱,采用不同比例的正己烷/异丙醇作为流动相对一系列外消旋化合物进行手性拆分.结果显示,该手性柱对醇类、酮类、黄酮、酚类、胺类等17种外消旋化合物表现了较好的手性拆分能力.将该手性柱与之前我们报道的3种手性MOFs柱相比较,其表现出了更好的手性选择性,具有较好的手性拆分互补作用.最后还对该手性柱的重现性和稳定性做了评价,结果表明该手性柱表现出较好的重现性和稳定性.     

超高效合相色谱法拆分和测定克伦特罗对映体

建立了基于超高效合相色谱技术(UPC²)的克伦特罗对映体拆分方法,并对所建立的方法进行了方法学考察及应用。实验考察了两种克伦特罗对映体标准溶液的稳定性,并对手性色谱柱、助溶剂、系统背压、色谱柱温度等色谱分离条件进行了优化。采用Acquity Trefoil AMY1 (150 mm×3.0 mm, 2.5 μm)手性色谱柱进行分离,以超临界CO₂-含0.5%(v/v) 10 mol/L醋酸铵的甲醇溶液为流动相,以流速2.0 mL/min梯度洗脱,检测波长为241 nm,进样体积为10 μL,系统背压为13.8 MPa,柱温为40 ℃时,两种克伦特罗对映体分离效果最好。两种克伦特罗对映体的线性范围为1.0~20.0 mg/L,相关系数均大于0.9997,仪器检出限(S/N=3)均为0.5 mg/L。10.0 mg/L混合标准工作溶液重复进样6次,(+)、(-)克伦特罗对映体峰面积的相对标准偏差(RSD, n=6)分别为0.65%和0.76%。应用该方法对市售克伦特罗外消旋体标准品进行拆分,采用外标定量法计算克伦特罗外消旋体标准中间溶液10.0 mg/L中两种克伦特罗对映体含量,其中(+)-克伦特罗的含量为5.6 mg/L, (-)-克伦特罗的含量为5.5 mg/L。该计算结果与文献报道的工业品克伦特罗外消旋体中(+)-克伦特罗与(-)-克伦特罗的比例为1.02∶1.00基本相符。该方法具有分析速度快、分离效果好、有机溶剂消耗少等特点,适用于克伦特罗对映体的拆分,为其他手性化合物的拆分、药效精细分析和产品质量评定提供了可靠的技术支持。     

基于共价有机框架材料TpPa-NH2-Glu的高效液相色谱固定相用于分离手性化合物

共价有机框架材料（COFs）是一类由多齿有机单元通过共价键连接而成的新兴孔晶体材料。通过合成后修饰所得到的COFs通常具有较高的结晶度与孔隙率,并且在手性拆分、不对称催化与色谱分析等领域具有良好的应用价值。该文用1,3,5-三甲醛间苯三酚与2-硝基-1,4-苯二胺合成TpPa-NO₂,对其还原得到TpPa-NH₂,然后通过合成后修饰策略将D-葡萄糖修饰到该材料上,得到手性材料TpPa-NH₂的D-葡萄糖衍生物（TpPa-NH₂-Glu）。利用“网包法”将其固载在球形硅胶表面用作高效液相色谱固定相并制备了液相色谱柱,分别以正己烷-异丙醇（9∶1, v/v）或甲醇-水（9∶1, v/v）为流动相,流速0.5 mL/min,成功拆分了16种包括多个手性药物的外消旋体和2种苯系位置异构体o,m,p-硝基苯胺和o,m,p-碘苯胺。在甲醇-水（9∶1, v/v）流动相条件下,拆分了5种外消旋体,其中盐酸普萘洛尔、华法林、美托洛尔达到了基线分离;在正己烷-异丙醇（9∶1, v/v）流动相条件下,拆分了11种外消旋体,其中2-溴丙酸乙酯、3-丁炔-2-醇达到了基线分离。此外还探究了温度对TpPa-NH₂-Glu液相色谱柱的影响以及TpPa-NH₂-Glu液相色谱柱的重复性,结果表明,温度对TpPa-NH₂-Glu所制备的高效液相色谱柱影响不大,且TpPa-NH₂-Glu所制备的高效液相色谱柱具有良好的重复性,其相对标准偏差（RSD）分别为1.55%和1.46%。实验结果表明,TpPa-NH₂-Glu对手性化合物有良好的拆分能力。     

柱前衍生化高效液相色谱手性固定相法拆分手性氰醇

利用正相高效液相色谱法在多糖衍生物手性固定相(OJ-H、OD-H、AD-H或AS-H)上成功地分离了一系列(31个)氰醇对映体的乙酰化或丙酰化衍生物,并拆分了3个脂肪族氰醇对映体的乙酰化衍生物。探讨了这些外消旋体在这四支手性柱上的色谱行为,通过考察流动相组成、流速、进样浓度和温度等因素对对映体拆分效果的影响,优化了色谱分离条件。方法已应用于脂肪酶催化转酯化拆分反应中手性氰醇衍生物的光学纯度的鉴定。     

农药甲霜灵对映体的高效液相色谱分离及手性拆分热力学研究

以正己烷 异丙醇为流动相 ,在纤维素 三 (3 ,5 二甲基苯基氨基甲酸酯 ) (CDMPC)涂敷型手性固定相上 ,对农药甲霜灵外消旋体进行了拆分 ,考察了流动相组成、柱温等对甲霜灵对映体的保留和分离的影响 ;对甲霜灵R、S对映体与固定相之间的保留和分离的热力学机理进行了讨论     

键合型聚丙烯酰胺衍生物手性固定相的制备与手性识别性能

高效液相色谱(HPLC)被广泛认为是分离制备光学纯单一对映体的最有效方法。在高效液相色谱手性拆分中,手性固定相(CSP)的性能直接影响到色谱柱的手性分离能力。在众多手性固定相中,键合型手性固定相具有溶剂耐受性好,分离模式灵活等优点,已经发展成为一类重要的手性固定相。本文通过两步化学反应合成了新型的光学活性丙烯酰胺衍生物--(S)-1-丙烯酰-2-(N-苯基甲酰胺基)吡咯烷((S)-APACP),采用核磁共振氢谱表征了(S)-APACP的化学结构;通过3步化学反应制备了键合型聚丙烯酰胺衍生物手性固定相,采用热重分析法表征了聚合物的键合量,采用HPLC评价了键合型手性固定相的识别能力,分析了影响其手性识别能力的因素。研究结果表明,APACP聚合物成功地键合到硅胶表面制备了具有良好溶剂耐受性的键合型手性固定相,其聚合物键合量为10.2%~11.8%,该键合型手性固定相对若干种对映体显示了较好的手性识别能力。     

键合型纤维素类手性固定相高效液相色谱法拆分对映异构体

制备了一种键合型纤维素-三苯基氨基甲酸酯手性固定相。在正相色谱条件下，拆分了九种结构不同的外消旋对映体，实验发现，在流动相中添加四氢呋喃有利于手性化合物拆分，而衍生化官能团可参与手性识别过程，在反相色谱条件下，此固定相同样具有手性拆分能力。研究结果表明，随着流动相中乙腈浓度的增加，对映体的保留值明显减小，但对映异构体的选择性却变化不大。在流动相中使用低pH值，能有效抑制酸性化合物的解离，从而显著增强其手性识别能力；对于中性化合物，流动相中pH对手性分离影响不大。     

禾草灵对映体在纤维素-三(3,5-二甲基苯基氨基甲酸酯)手性固定相上的拆分

将纤维素-三(3,5-二甲基苯基氨基甲酸酯)(CDMPC)涂敷于自制的球形氨丙基硅胶上,制备了手性固定相.在正相条件下,用高效液相色谱法在该固定相上直接拆分了农药禾草灵的外消旋体,并系统地选用了多种二元及三元流动相体系对样品进行拆分.实验结果表明,流动相中不同的醇类改性剂及其含量的不同对样品保留时间和立体选择性有不同程度的影响,选用异丙醇改性剂时样品的拆分效果较好,在三元流动相体系正己烷/异丙醇/乙醇中可以实现对禾草灵外消旋体快速有效的拆分.     

Separation of α-cyclohexylmandelic acid enantiomers using biphasic chiral recognition high-speed counter-current chromatography

This work concentrates on a chiral separation technology named biphasic recognition applied to resolution of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography (HSCCC). The biphasic chiral recognition HSCCC was performed by adding lipophilic (−)-2-ethylhexyl tartrate in the organic stationary phase and hydrophilic hydroxypropyl-β-cyclodextrin in the aqueous mobile phase, which preferentially recognized the (−)-enantiomer and (+)-enantiomer, respectively. The two-phase solvent system composed of n-hexane-methyl tert-butyl ether–water (9:1:10, v/v/v) with the above chiral selectors was selected according to the partition coefficient and separation factor of the target enantiomers. Important parameters involved in the chiral separation were investigated, namely the types of the chiral selectors (CS); the concentration of each chiral selector; pH of the mobile phase and the separation temperature. The mechanism involved in this biphasic recognition chiral separation by HSCCC was discussed. Langmuirian isotherm was employed to estimate the loading limits for a given value of chiral selectors. Under optimum separation conditions, 3.5–22.0 mg of α-cyclohexylmandelic acid racemate were separated using the analytical apparatus and 440 mg of racemate was separated using the preparative one. The purities of both of the fractions including (+)-enantiomer and (−)-enantiomer from the preparative CCC separation were over 99.5% determined by HPLC and enantiomeric excess reached 100% for the (±)-enantiomers. Recovery for the target compounds from the CCC fractions reached 85–88% yielding 186 mg of (+)-enantiomer and 190 mg of (−)-enantiomer. The overall experimental results show that the HSCCC separation of enantiomer based on biphasic recognition, in which only if the CSs involved will show affinity for opposite enantiomers of the analyte, is much more efficient than the traditional monophasic recognition chiral separation, since it utilizes the cooperation of both of lipophilic and hydrophilic chiral selectors.     

Use of enantioselective liquid chromatography for preparation of pure atenolol enantiomers

The study reported here shows a practicable preparation of pure atenolol enantiomers using enantioselective liquid chromatography. The successful separation of enantiomers of the final atenolol and the intermediate ester and the good peak shapes could not have been obtained without diethylamine as a component of the mobile phase. That makes difficult the recycling of the three-component mobile phase, an unavoidable step in simulated moving bed chromatography separation technology. The only suitable methodology for preparation of atenolol enantiomers proved to be synthesis from its N-benzyl-N-isopropyl precursor and the chiral stationary phase Chiralpak AD was found to be very convenient for preparative separation of these enantiomers. The enantiomeric purities and recovery of separated enantiomers of this N-benzyl-N-isopropyl precursor were very high, allowing high enantiomeric purities of the final products, ee's 99.3% for S- and 99.0% for R-atenolol. The chromatographic separation parameters, as well as solubility of racemate in the mobile phase, are good bases for the further examination of possible scale-up resolution of compound 6.     

Simulated moving bed chromatography for the separation of enantiomers

Simulated moving bed (SMB) chromatography, a continuous multi-column chromatographic process, has become one of the preferred techniques for the separation of the enantiomers of a chiral compound. Several active pharmaceutical ingredients, including blockbuster drugs, are manufactured using the SMB technology. Compared to single column preparative chromatography, SMB separations achieve higher productivity and purity, while reducing the solvent consumption. The SMB technology has found applications both at small and large scales. Design methods have been developed for robust operation and scale-up, using data obtained from analytical experiments. In the last few years, rapid developments have been made in the areas of design, improved process schemes, optimization and robust control. This review addresses these developments, as well as both the fundamentals of the SMB science and technology and some practical issues concerning the operation of SMB units. Particular emphasis is placed on the consolidation of the “triangle theory”, a design tool that is used both in the academia and industry for the design of SMB processes.     

Impact of adsorption isotherm parameters on the performance of enantioseparation using simulated moving bed chromatography

Often there are several chromatographic systems, i.e., combinations of mobile and stationary phases, available to solve a certain separation problem. Essential differences of these chromatographic systems are the separation factors and the efficiencies. For preparative applications in addition also the column saturation capacities and solubility limits are of importance. The impact of all these parameters appears to be rather well understood for conventional overloaded elution chromatography using a single column. In the last years the continuous simulated moving bed (SMB) process was increasingly used as a powerful alternative to batch elution since increased productivities and reduced solvent consumptions could be realised. However, the selection of suitable chromatographic systems is more sophisticated for this process. In this paper five different chromatographic systems capable of separating the enantiomers of mandelic acid are compared based on the achievable productivities using SMB chromatography. For these five systems the adsorption isotherms have been determined experimentally. Subsequently, an analysis of the SMB process was performed numerically using a well-established model.     

Resolution of a racemic pharmaceutical intermediate. A comparison of preparative HPLC, steady state recycling, and simulated moving bed

Preparative HPLC and simulated moving bed (SMB) chromatography were used to resolve significant quantities of a racemic pharmaceutical intermediate. In addition, smaller scale studies using closed-loop recycling and steady state recycling (SSR) were performed so that a meaningful comparison of all these techniques could be made using the same real world separation. A highly optimized, six-column SMB process was clearly the superior technique and was used for the process-scale (247 kg of racemate) resolution. At the more moderate lab-scale (33 kg of racemate and 19 kg of racemate), a frequently used but less optimized eight-column SMB process was used. It was found that SSR was comparable to the lab-scale SMB process in productivity and solvent consumption. Thus, it appears that SSR can be a useful choice at such moderate scales. Finally, at moderate scales when neither SSR nor SMB is available, it was found that acceptable results were obtained with both closed-loop recycling and with a two-step preparative process.     

"Figure Eight" Cyclooctapyrroles: Enantiomeric Separation and Determination of the Absolute Configuration of a Binuclear Metal Complex

The hypothesized racemate separation of cyclooctapyrroles with chiral figure eight conformations-and of metal complexes derived from these ligands-has been realized. The cyclooctapyrrole 1 (as hexadecaethyl derivative), which according to NMR analysis exhibits restricted mobility, and its binuclear palladium and copper complexes could be separated into stable enantiomers by preparative chromatography on a chiral phase. In the case of the palladium complex and the free ligand 1 it was also possible to determine the absolute configuration of the enantiomers.     

Direct enantiomeric high performance liquid chromatographic separation of aminoglutethimide and its major metabolite on a series of Chiralcel OD and Chiralcel OJ columns and its application to biological fluids

A direct, isocratic, sensitive and precise liquid chromatographic method is presented for the enantiomeric separation of aminoglutethimide (AG) and its acetylated metabolite (AcAG) using cellulose tris-3,5-dimethyl phenyl carbamate (Chiralcel OD) and cellulose tris(4-methylphenyl benzoate) ester (Chiralcel OJ) columns in series. The enantiomeric elution order is determined by separate chromatography of the racemate AG and racemate AcAG and of their separate enantiomers under similar conditions. This method has been used to determine and identify the enantiomers of AG and AcAG in the urine sample collected from a metastatic breast cancer patient after administration of AG for 24 h. Large amounts of (+)-R-AG are excreted unchanged in the urine together with smaller quantities of (+)-R-AcAG, while most of the (-)-S-AG is metabolically converted into (-)-S-AcAG.     

制备分离农药甲霜灵对映体的高效液相色谱法

用高效液相色谱法对自制的纤维素－三（3，5－二甲基苯基氨基甲酸酯）手性制备柱的手性拆分能力进行了评价，并且在此制备柱上完成了对手性农药甲霜灵进行了半制备分离；同时对手性农药甲霜灵在纤维素－三（苯基氨基甲酸酯）、直链淀粉－三（苯基氨基甲酸酯）、纤维素－三（4－甲基苯甲酸酯）手性分析柱上的手性拆分进行了研究。     

Batch and simulated moving bed chromatographic resolution of a pharmaceutical racemate

The preparative chromatographic resolution of racemates has become over the past few years a standard approach for the generation of enantiomers in pharmaceutical research and development. This paper will discuss the chromatographic resolution of a racemic pharmaceutical intermediate. Initial analytical method development to determine the best preparative conditions will be presented. Batch resolution of kg quantities of racemate followed by the simulated moving bed resolution of tens and hundreds of kg of racemate will also be discussed. Finally the different approaches used for the separation will be compared.