Triticonazole enantiomers: Separation by supercritical fluid chromatography and the effect of the chromatographic conditions

Isoflavones are natural substances that exhibit hormone-like pharmacological activities. The separation of isoflavones remains an analytical challenge because of their similar structures. We show that ultra-high performance supercritical fluid chromatography can be an appropriate tool to achieve the fast separation of 12 common dietary isoflavones. Among the five tested columns the Torus DEA column was found to be the most effective column for the separation of these isoflavones. The impact of individual parameters on the retention time and separation factor was evaluated. These parameters were optimized to develop a simple, rapid, and green method for the separation of the 12 target analytes. It only took 12.91 min using gradient elution with methanol as an organic modifier and formic acid as an additive. These isoflavones were determined with limit of quantitation ranging from 0.10 to 0.50 μg/mL, which was sufficient for reliable determination of various matrixes.

“…The separation factor (α) has been widely used to describe separation selectivity, which is determined using the following equation:

α = (t_{2} - t_{0}) / (t_{1} - t_{0})

Section: Resultsmentioning

confidence: 99%

Simple, rapid, and environmentally friendly method for the separation of isoflavones using ultra‐high performance supercritical fluid chromatography

Zhang

et al. 2017

“…The use of SFC for enantioselective separations has become a welcome extension in the application field of SFC. For both analytical and preparative scale analyses, enantioseparation in SFC offers some advantages over HPLC . In combination with effective chiral stationary phases (CSPs), it is a potent tool that can be employed for separations of enantiomers in pharmaceutical laboratories, as well as environmental and food‐control labs .…”

Section: Introductionmentioning

confidence: 99%

“…in SFC offers some advantages over HPLC [1][2][3]. In combination with effective chiral stationary phases (CSPs), it is a potent tool that can be employed for separations of enantiomers in pharmaceutical laboratories, as well as environmental and food-control labs [4].…”

Section: Introductionmentioning

confidence: 99%

Cellulose tris‐(3,5‐dimethylphenylcarbamate)‐based chiral stationary phase for the enantioseparation of drugs in supercritical fluid chromatography: comparison with HPLC

Kalíková

Martínková

Schmid

et al. 2018

A cellulose tris-(3,5-dimethylphenylcarbamate)-based chiral stationary phase was studied as a tool for the enantioselective separation of 21 selected analytes with different pharmaceutical and physicochemical properties. The enantioseparations were performed using supercritical fluid chromatography. The effect of the mobile phase composition was studied. Four different additives (diethylamine, triethylamine, isopropylamine, and trifluoroacetic acid) and isopropylamine combined with trifluoroacetic acid were tested and their influence on enantioseparation was compared. The influence of two different mobile phase co-solvents (methanol and propan-2-ol) combined with all the additives was also evaluated. The best mobile phase compositions for the separation of the majority of enantiomers were CO /methanol/isopropylamine 80:20:0.1 v/v/v or CO /propan-2-ol/isopropylamine/trifluoroacetic acid 80:20:0.05:0.05 v/v/v/v. The best results were obtained from the group of basic β-blockers. A high-performance liquid chromatography separation system composed of the same stationary phase and mobile phase of similar properties prepared as a mixture of hexane/propan-2-ol/additive 80:20:0.1 v/v/v was considered for comparison. Supercritical fluid chromatography was found to yield better results, i.e. better enantioresolution for shorter analysis times than high-performance liquid chromatography. However, examples of enantiomers better resolved under the optimized conditions in high-performance liquid chromatography were also found.

“…The resolution factor ( R s ) is obtained from the software calculations using R s = 1.177 ( t R2 – t R1 ) / ( w 1 + w 2 ), where t R is the retention time of the stereoisomer (min), w is the peak width measured at half height, and subscripts 1 and 2 represent the former and the latter eluted enantiomers, respectively . The retention factors, namely k 1 , k 2 , k 3 , and k 4 , are calculated by the equation k = ( t R − t 0 ) / t 0 , where t 0 is the retention time of 1,3,5‐ tert ‐butylbenzene.…”

Section: Methodsmentioning

confidence: 99%

Efficient preparative separation of β‐cypermethrin stereoisomers by supercritical fluid chromatography with a two‐step combined strategy

Yan

Fan

Lai³

et al. 2018

Self Cite

An efficient two-step method has been developed for the separation of β-cypermethrin stereoisomers by supercritical fluid chromatography with polysaccharide chiral stationary phases. With respect to retention, selectivity, and resolution of β-cypermethrin, the effects of chiral stationary phases, cosolvents, mobile phases, and column temperature have been studied in detail. Through a two-step separation, β-cypermethrin was firstly separated by using a cellulose-derived chiral stationary phase to obtain two stereoisomeric pairs, and further resolved on an amylose-based chiral stationary phase to produce four enantiopure stereoisomers. The electronic circular dichroism patterns of the first- and the third-eluted isomers in methanol solution showed the mirror image of each other in the wavelength range 200∼300 nm, indicating that they were a pair of enantiomers. Moreover, the second- and the fourth-eluted isomers were also enantiomers. This proposed two-step strategy showed low solvent consumption, fast separation speed, and high-purity, which may provide an effective approach for preparative separation of compounds with multiple chiral centers and difficult-to-separate multicomponent samples.