Expanding the applicability of cork as extraction phase for disposable pipette extraction in multiresidue analysis of pharmaceuticals in urine samples.

In this paper, cork is proposed as a natural and renewable material for the extraction phase in disposable pipette extraction to be applied in the multiresidue determination of pharmaceuticals in human urine by HPLC with diode array detection. The compounds carbamazepine, losartan, ketoprofen, 17‑β‑estradiol, naproxen, diazepam, 17‑α‑ethinylestradiol, estrone, diclofenac and ibuprofen were studied. A known amount (5 mg) of cork, with a size of 200 mesh, was inserted into a pipette tip.

Dual-opposite end multiple injection method applied to sequential determination of Na, K, Ca, Mg ions and free and total glycerol in biodiesel by capillary zone electrophoresis.

A novel method for the sequential determination of sodium, potassium, calcium, and magnesium and free and total glycerol in biodiesel by capillary zone electrophoresis is proposed herein. The inorganic cations were separated along an effective length of 43.5 cm.

Magnetic ionic liquids as versatile extraction phases for the rapid determination of estrogens in human urine by dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography-diode array detection.

In this study, a rapid and straightforward approach based on magnetic ionic liquids (MIL) as extraction phases and dispersive liquid-liquid microextraction (DLLME) was developed to analyze the hormones estriol, 17-β-estradiol, 17-α-ethynylestradiol, and estrone in human urine samples. This is the first report of an application of manganese-based MILs compatible with HPLC to extract compounds of biological interest from urine samples. The hydrophobic MILs trihexyltetradecylphosphonium tetrachloromanganate (II) ([P][MnCl]) and aliquat tetrachloromanganate (II) ([Aliquat][MnCl]) were employed and the optimized extraction conditions were comprised of 5 mg of MIL ([P][MnCl]), 5 μL of methanol (MeOH) as disperser solvent, and an extraction time of 90 s at sample pH 6.

High-Throughput Analysis of Lidocaine in Pharmaceutical Formulation by Capillary Zone Electrophoresis Using Multiple Injections in a Single Run.

This paper reports the development of a subminute separation method by capillary zone electrophoresis in an uncoated capillary using multiple injection procedure for the determination of lidocaine in samples of pharmaceutical formulations. The separation was performed in less than a minute leading to doing four injections in a single run. The cathodic electroosmotic flow contributed to reducing the analyses time.

Exploring the charged nature of supramolecular micelles based on p-sulfonatocalix[6]arene and dodecyltrimethylammonium bromide.

The aggregation of supramolecular amphiphiles formed from hexamethylated p-sulfonatocalix[6]arene (SC6HM) and dodecyltrimethylammonium bromide (C12TAB) was studied by capillary electrophoresis experiments and by kinetic probes. The hydrolysis of 4-methoxybenzenesulfonyl chloride (MBSC) was used to investigate the micropolarity of the micellar aggregates and their ability to solubilize and stabilize labile organic compounds against hydrolysis. Further insights were obtained using a more sophisticated kinetic probe: the basic hydrolysis of p-nitrophenylvalerate (NPV).

Superficially Porous Particle Based Hydroxypropyl-β-cyclodextrin Stationary Phase for High-Efficiency Enantiomeric Separations.

A superficially porous particle (SPP)-based hydroxypropyl-β-cyclodextrin (HPBCD) chiral stationary phase (CSP) was produced and its chromatographic performance was compared to both 5 µm and 3 µm fully porous particle (FPP)-based CSPs. The relative surface coverage of the HPBCD chiral selector on each particle was approximately equal, which resulted in equivalent enantiomeric selectivity (α) values on each phase when constant mobile phase conditions were used. Under such conditions, the SPP column resulted in greatly reduced analysis times and three times greater efficiencies compared to the FPP columns.

Comparison of superficially porous and fully porous silica supports used for a cyclofructan 6 hydrophilic interaction liquid chromatographic stationary phase.

A new HILIC stationary phase comprised of native cyclofructan-6 (CF6) bonded to superficially porous silica particles (2.7μm) was developed. Its performance was evaluated and compared to fully porous silica particles with 5μm (commercially available as FRULIC-N) and 3μm diameters.

Superficially porous particles vs. fully porous particles for bonded high performance liquid chromatographic chiral stationary phases: isopropyl cyclofructan 6.

This work reports a comparison of HPLC separations of enantiomers with chiral stationary phases (CSPs) prepared by chemically bonding cyclofructan-6, functionalized with isopropyl carbamate groups on fully and superficially porous particles (SPPs). The chromatographic performance of the superficially porous CSP based column was compared with columns packed with 5 μm and 3 μm fully porous particles (FPPs). At a flow rate of 3.

Simultaneous determination of free and total glycerol in biodiesel by capillary electrophoresis using multiple short-end injection.

A rapid method for the simultaneous determination of free glycerol (FG) and total glycerol (TG) in biodiesel by CE using a short-end multiple injection (SE/MI) configuration system is described. The sample preparation for FG involves the extraction of glycerol with water and for TG a saponification reaction is carried out followed by extraction as in the case of FG. The glycerol extracted in both cases is submitted to periodate oxidation and the iodate ions formed are measured on a CE-SE/MI system.

5-Azacytidine combined with 2,4-D improves somatic embryogenesis of Acca sellowiana (O. Berg) Burret by means of changes in global DNA methylation levels.

Unlabelled: DNA methylation is an epigenetic regulatory mechanism of gene expression which can be associated with developmental phases and in vitro morphogenetic competence in plants. The present work evaluated the effects of 5-azacytidine (AzaC) and 2,4-dichlorophenoxyacetic acid (2,4-D) on Acca sellowiana somatic embryogenesis (SE) and global DNA methylation levels by high-performance liquid chromatography mass spectrometry (HPLC/MS/MS). 2,4-D-free treatments revealed no somatic embryo formation in both accessions tested.