In this study, 1-methylimidazolium hydrogen sulfate, [HMIM]HSO 4 , ionic liquid, was successfully applied as a catalyst in the biodiesel production through the esterification reaction of oleic acid with methanol. A response surface methodology (RSM) known as Box-Behnken Design (BBD) was applied to optimize the main experimental reaction conditions, using a set of 27 experiments. This optimization was based on the maximization of both the conversion of oleic acid and the Fatty Acid Methyl Esters (FAME) content of the obtained biodiesel samples. It was concluded that the two most relevant parameters for both the conversion and the FAME content were the molar ratio between oleic acid and methanol and the catalyst dosage. Accordingly to the model, the optimum condition for the maximum conversion was determined as being 8 h, 110 ± 2°C, 15:1 M ratio methanol/oleic acid and a catalyst dosage of 15 wt%, resulting in a 95% conversion and for the maximum FAME content were 8 h, 110 ± 2°C, 14:1 M ratio and a catalyst dosage of 14 wt%, leading to a FAME content of 90%. The kinetics of the esterification reaction was also evaluated, and the experimental results were well described using a third-order reaction model. The kinetic parameters were experimentally determined, and the value of the activation energy was 6.8 kJ/mol and the pre-exponential factor was 0.0765 L 2 .mol −2 .min −1 confirming that the ionic liquid, [HMIM]HSO 4 , is a good alternative for replacing traditional catalysts for biodiesel production through esterification reaction.

The separation of the four nadolol stereoisomers on Chiralpak® AD by chiral liquid chromatography was carried out at both analytical and preparative scales. A screening of possible mobile-phase compositions was performed using different alcohol-hydrocarbon mixtures. The results obtained confirm the use of 20:80:0.3 ethanol-hexane-diethylamine reported by McCarthy (1994) but introduce other possibilities for the complete resolution of the four nadolol stereoisomers at analytical scale, namely, the mixtures 30-40:70-60:0.3 ethanol-heptane-diethylamine. Additionally, this work describes how retention and resolution depend on the ethanol content in hexane and heptane mixtures. The separation of nadolol stereoisomers is also carried out at preparative scale and different alcohol-hydrocarbon compositions are proposed, depending on the target component to be obtained. Particularly, this work presents the experimental separation of the more retained nadolol stereoisomer (RSR-nadolol) by simulated moving bed (SMB) chromatography using an 80:20:0.3 ethanol-heptane-diethylamine mobile phase. For a 2 g/l feed concentration, RSR-nadolol is 100% recovered at the extract outlet stream, 100% pure, and with a system productivity of 0.65 g(RSR-nadolol)/(l(bed)(.)h) and a solvent consumption of 9.6 l(solvent)/g(RSR-nadolol).

The present work intends to investigate how mobile phase composition influences the adsorption behavior of ketoprofen enantiomers (a nonsteroidal anti-inflammatory drug) on an amylose-based chiral stationary phase (Chiralpak AD). Three mobile phase compositions were studied: the usual 20% ethanol/80% n-hexane mixture and two pure mobile phases; methanol and ethanol. Pulse and breakthrough experiments under preparative conditions were carried out in order to measure and test adsorption isotherms. The results obtained show that, for preparative separations, pure ethanol is a better mobile phase than the usual 20% ethanol/80% n-hexane mixture: it allows higher solubility of the racemate, lower retention times, and also a higher selectivity at high enantiomer concentrations. These are aspects of crucial importance when the final goal is to achieve high productivity preparative separations, as it is shown for the simulated moving bed (SMB) operation.

Chiralpak IA adsorbent is used for both analytical and preparative chromatographic separation of nadolol stereoisomers. The results include a complete screening of the mobile phase composition for both the baseline resolution of all four nadolol stereoisomers (analytical separation) and the simulated moving bed (SMB) pseudo-binary separation of the most retained stereoisomer. The experimental results show that analytical baseline resolution of nadolol stereoisomers can be achieved using alcohol/hydrocarbon and alcohol/acetonitrile solvent mixtures. The 10%ethanol/90%acetonitrile mixture is presented as the one that presents baseline resolution with lower retention. For the preparative pseudo-binary separation, pure ethanol, pure methanol, alcohol/acetonitrile, and alcohol/tetrahydrofuran mixtures proved to allow good separation results. The 100%methanol/0.1%diethylamine solvent composition was selected to perform the experimental SMB separation. Using a 10 g/L total feed concentration, the more retained stereoisomer was recovered at the extract outlet stream with 99.5% purity, obtaining a system productivity of 1.98 gL(-1)  h(-1) and requiring a solvent consumption of 3.13 L/g of product. Comparing these results with the ones recently presented by Ribeiro et al. (2013), this work shows that the Chiralpak IA chiral adsorbent is an interesting alternative to Chiralpak AD for the separation of nadolol stereoisomers at both analytical and preparative scales. Chirality 28:399-408, 2016. © 2016 Wiley Periodicals, Inc.

The pharmaceutical industry is now directed to the market of more safety and efficient drugs, based on single enantiomers. Ketoprofen, still used as a racemic pharmaceutical drug, belongs to the profens class, one of the most representative of the non-steroidal anti-inflammatory drugs. This work presents the chiral separation of ketoprofen enantiomers by simulated moving bed technology, using a laboratory scale unit (the FlexSMB-LSRE 1 ) with six columns, packed with the Chiralpak AD 1 stationary phase (20 lm). A comparative study between a mobile phase composed of a traditional high hydrocarbon content (10%ethanol=90%n-hexane=0-.01%TFA) and a strong polar organic composition (100%ethanol= 0.01%TFA) is presented. The study includes the measurement of the adsorption isotherms, elution, and frontal chromatography experiments, carried out on a SMB column for both compositions. The results obtained allowed the prediction and optimization of the SMB operation. Using pure ethanol as solvent and a racemic feed concentration of 40 g=L, purities above 98.6% on both outlet streams were obtained, with a productivity of 3.84 g feed =(L bed .hr) and a solvent consumption of 0.78 L solvent =g feed . The results obtained in the experimental separation of ketoprofen enantiomers by SMB chromatography indicates that pure ethanol presents better performances than the classic high hydrocarbon content composition.