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Tomić J, Ivković B, Oljačić S, Nikolić K, Maljurić N, Protić A, Agbaba D. Chemometrically assisted RP-HPLC method development for efficient separation of ivabradine and its eleven impurities. ACTA CHROMATOGR 2020. [DOI: 10.1556/1326.2019.00659] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aim of this study was to develop a novel reversed-phase high-performance liquid chromatography (RP-HPLC) method for efficient separation of ivabradine and its 11 impurities. Similar polarity of impurities in the sample mixture made method optimization challenging and accomplishable only when different chemometric tools, such as principal component analysis (PCA), Box–Behnken design (BBD), and desirability function as a multicriteria approach, were employed. The presence of 3 positional isomers (impurities III, V, and VI), keto–enol tautomerism of impurity VII, and diastereoisomers of impurity X made separation of this complex mixture even more challenging. Chromatographic retention parameters obtained with the mobile phase consisting of 30 mM phosphate buffer and acetonitrile (80:20, v/v) on four different RP-HPLC columns at varying pH values (3.0, 4.0, and 5.0) were subjected to the PCA analysis to select the column with the most appropriate selectivity. Then the column temperature, pH of the aqueous component of mobile phase, phosphate buffer molarity and the organic solvent content in the mobile phase were estimated employing BBD. Valid and reliable mathematical models towards resolution of twelve critical peak pairs were obtained. After determination of the desirability making criteria for all responses, desirability functions were established and used in optimization. The proposed optimal chromatographic conditions included the Zorbax Eclipse Plus C18 chromatographic column (100 × 4.6 mm, 3.5 μm), the column temperature of 34 °C, the mobile phase flow rate of 1.6 mL min−1 and the UV detection at 220 nm. The mobile phase consisted of the 28 mM phosphate buffer at pH 6.0 and acetonitrile (85:15, v/v). Separation of one pair of positional isomers was not achieved, so methanol was added to the organic part of mobile phase in small increments with the optimal ratio of methanol to acetonitrile 59:41, v/v. The overall organic component of the mobile phase also increased to 18%, accelerating the chromatographic analysis.
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Affiliation(s)
- Jovana Tomić
- 1 University of Belgrade Faculty of Pharmacy, Department of Pharmaceutical Chemistry Vojvode Stepe 450, 11 221 Belgrade, Serbia
| | - Branka Ivković
- 1 University of Belgrade Faculty of Pharmacy, Department of Pharmaceutical Chemistry Vojvode Stepe 450, 11 221 Belgrade, Serbia
| | - Slavica Oljačić
- 1 University of Belgrade Faculty of Pharmacy, Department of Pharmaceutical Chemistry Vojvode Stepe 450, 11 221 Belgrade, Serbia
| | - Katarina Nikolić
- 1 University of Belgrade Faculty of Pharmacy, Department of Pharmaceutical Chemistry Vojvode Stepe 450, 11 221 Belgrade, Serbia
| | - Nevena Maljurić
- 2 University of Belgrade, Faculty of Pharmacy, Department of Drug Analysis Vojvode Stepe 450, 11 221 Belgrade, Serbia
| | - Ana Protić
- 2 University of Belgrade, Faculty of Pharmacy, Department of Drug Analysis Vojvode Stepe 450, 11 221 Belgrade, Serbia
| | - Danica Agbaba
- 1 University of Belgrade Faculty of Pharmacy, Department of Pharmaceutical Chemistry Vojvode Stepe 450, 11 221 Belgrade, Serbia
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Microwave-assisted versus conventional decomposition procedures applied to a ceramic potsherd standard reference material by inductively coupled plasma atomic emission spectrometry. Anal Chim Acta 2004. [DOI: 10.1016/s0003-2670(03)00357-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Le Mapihan K, Vial J, Jardy A. Testing of “special base” columns in reversed-phase liquid chromatography. J Chromatogr A 2004; 1030:135-47. [PMID: 15043263 DOI: 10.1016/j.chroma.2003.10.099] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A methodology for building a chromatographic test aiming at characterizing special base stationary phases was described. Instead of choosing its conditions a priori, a "full" comprehensive test based on extended running conditions was performed on a 12 column set. The conditions were carefully chosen from their ability to take into account the solvent and the pH effects. Principal component analysis (PCA) has been combined to hierarchical cluster analysis both to provide interpreted classifications and to reduce drastically the test itself by eliminating redundant information. The final reduced test can be considered optimal because the minimized set of test conditions allows to provide as much information as in the initial full test.
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Affiliation(s)
- K Le Mapihan
- Laboratoire "Environnement et Chimie Analytique", UMR 7121, Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, 10 Rue Vauquelin 75005 Paris, France
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Götz R, Lauer R. Analysis of sources of dioxin contamination in sediments and soils using multivariate statistical methods and neural networks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2003; 37:5559-5565. [PMID: 14717164 DOI: 10.1021/es030073t] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Multivariate statistical methods and neuronal networks were used to evaluate the concentration dioxin patterns of a large data set (407 samples) in order to identify the dioxin sources of contaminated waters (sediment and suspended particulate matter samples). The evaluations indicated that a considerable proportion of the dioxin contamination of the river Elbe in the section between the Mulde tributary and the North Sea and their flood plains (soil samples) and the Port of Hamburg was caused by pollution originating from the Bitterfeld region, an industrial area of the former German Democratic Republic. The dioxin patterns of sediment samples from tributaries of the river Elbe in the Bitterfeld area itself are similar to dioxin patterns that can be attributed to metalworking processes. The dioxin patterns of the Hamburg inner city waters could be attributed to "incineration" dioxin sources, for example waste incineration plants. The results of cluster analysis applying different modes of distance measure and linkage compared well with neuronal networks. The number of clusters was determined based on the stability of the results of different cluster analyses and background information.
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Affiliation(s)
- Rainer Götz
- Behörde für Umwelt und Gesundheit, Institut für Hygiene und Umwelt, Marckmannstrasse 129 b, D-20539 Hamburg, Germany.
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Martínez Vidal JL, Egea González FJ, Garrido Frenich A, Martínez Galera M, Aguilera PA, López Carrique E. Assessment of relevant factors and relationships concerning human dermal exposure to pesticides in greenhouse applications. PEST MANAGEMENT SCIENCE 2002; 58:784-790. [PMID: 12192902 DOI: 10.1002/ps.524] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Principal component analysis (PCA) was applied to the gas chromatographic data obtained from 23 different greenhouse trials. This was used to establish which factors, including application technique (very small, small, medium and large drop-size), crop characteristics (short/tall, thin/dense) and pattern application of the operator (walking towards or away from the treated area) are relevant to the dermal exposure levels of greenhouse applicators. The results showed that the highest exposure by pesticides during field applications in greenhouses, in the climatic conditions and in the crop conditions typical of a southern European country, occurs on the lower legs and front thighs of the applicators. Similar results were obtained by hierarchical cluster analysis (HCA). Drop-size seems to be very important in determining total exposure, while height and density of crops have little influence on total exposure under the conditions of the present study. No pesticide type is a major factor in total exposure. The application of multiple regression analysis (MRA) allowed assessment of the relationships between the pesticide exposure of the less affected parts of the body with the most affected parts.
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Affiliation(s)
- Jose L Martínez Vidal
- Department of Hydrogeology and Analytical Chemistry, University of Almería, 04071 Almería, Spain.
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