Basil (Ocimum L.) species are used as medicinal plants due to their essential oils exhibiting specific biological activity. The present work demonstrated that both the variety and season/conditions of cultivation had a significant effect on (i) the produced amount (extraction yield), (ii) qualitative, as well as (iii) quantitative profile of basil essential oil. Among studied basil varieties, a new variety, ‘Mánes’, was characterized for the first time. Based on our quantitative evaluation of GC-MS profiles, the following chemotypes and average concentrations of a main component were detected in the studied basil varieties: ‘Ohře’, ‘Lettuce Leaf’, ‘Purple Opaal’, ‘Dark Green’ (linalool, 5.99, 2.49, 2.34, 2.01 mg/mL, respectively), and ‘Mammolo Genovese’, ‘Mánes’, ‘Red Rubin’ (eucalyptol, 1.34, 0.96, 0.76 mg/mL, respectively). At the same time, when considering other compounds identified in GC-MS profiles, all the studied varieties, except from ‘Lettuce Leaf’, were methyl eugenol-rich with a strong dependence of the eugenol:methyl eugenol ratio on the seasonal changes (mainly solar irradiation, but also temperature and relative humidity). More complex and/or variable (depending on the season and cultivation) chemotypes were observed with ‘Lettuce Leaf’ (plus estragole, 2.27 mg/mL), ‘Dark Green’ (plus eucalyptol, 1.36 mg/mL), ‘Mammolo Genovese’ (plus eugenol, 1.19 mg/mL), ‘Red Rubin’ (plus linalool and eugenol, 0.46 and 0.56 mg/mL, respectively), and ‘Mánes’ (plus linalool and eugenol, 0.58 and 0.40 mg/mL, respectively). When considering superior extraction yield (ca. 17 mL·kg−1, i.e., two to five times higher than other examined varieties) and consistent amounts (yields) of essential oil when comparing inter-seasonal or inter-year data (RSD and inter-year difference in mean yield values ˂2.5%), this new basil variety is very promising for use in the pharmaceutical, food, and cosmetic industries.

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In present paper, a miniaturized boron-doped diamond electrode (BDDE) was for the first time used as a reliable electrochemical sensor within the novel voltammetric protocol for the rapid and simple determination of dipyridamole (DIP). Cyclic voltammetric studies uncovered that the electrochemical oxidation of DIP was shown to be irreversible and diffusion-controlled process with single and well-developed signal at a potential of +0.45 V in Britton-Robinson buffer at pH 3.0. Using the suitable experimental conditions, the linearity for DIP determination was observed in the concentration ranges of 0.1−5.0 μM and 0.1−6.0 μM with the corresponding limits of detection of 40 nM and 60 nM as well as the intra-day repeatability with relative standard deviation below 5% for differential pulse and square-wave voltammetry, respectively. This protocol was successfully applied to the determination of DIP in pharmaceutical tablets with result in good compliance with that declared by the producer. Biological pertinence of the developed procedure was presented by analysis of model human urine samples with adequate recoveries. The proposed protocol with a miniaturized BDDE could represent an effective and alternative analytical implement for DIP determination instead of commonly used toxic mercury and chemically-modified electrodes in previously published methods.

The present work illustrated possibilities of column-coupling electrophoresis combined with DAD for the direct quantitative determination of trace drug (celiprolol, CEL) in clinical human urine samples. ITP, on-line coupled with CZE, served as an ideal injection technique (high sample load capacity, narrow and sharp drug zone). Moreover, the ITP provided an effective on-line sample pretreatment (preseparation, purification and preconcentration of the drug) producing analyte zone suitable for its direct detection and quantitation in CZE stage. Spectral DAD in comparison with single wavelength ultraviolet detection enhanced value of analytical information (i) verifying purity (i.e., spectral homogeneity) of drug zone (according to differences in spectrum profiles when compared tested and reference drug spectra) and (ii) indicating zones/peaks with spectra similar to the drug spectrum (potential structurally related metabolites). The characterization of trace analyte signals superposed on the baseline noise was more definite thanks to the application of background correction and smoothing procedure to the raw DAD spectra (producing relevant spectral response). The proposed ITP-CZE-DAD method was characterized by favorable performance parameters for CEL in urine matrices {e.g., the lower limit of quantification was 9.7 ng/mL, RSD and relative error of the determinations were lower than 3% (precision) and 1% (accuracy), respectively, analyte peak exhibited spectral homogeneity (reflecting separation selectivity), separation efficiency was 84,500 theoretical plates} and successfully applied in a trial pharmacokinetic study of CEL.