Optimization of the composition and pH of the mobile phase used for separation and determination of a series of quinolone antibacterials regulated by the European Union

Abstract

SummaryTo ensure the safety of human food the European Union (EU) has set tolerance levels for quinolone compounds in animal products, so screening and confirmatory analytical methods are required for monitoring of these drugs. In this work, the proportion of organic modifier and the pH of acetonitrile-water mixtures used as mobile phases were optimized for separation of a group of quinolones. Linear solvation energy relationship (LSER) formalism based on the single solvent polarity parameter E N was used to predict the chromatographic behaviour of the compounds as a function of the amount of acetonitrile in the mobile phase. Correlation bef,,veen retention and the pH of aqueous-organic mobile phases has also been used to optimize mobile-phase pH. The optimized mobile phase was a hnear gradient starting from 18:82 (v/v) acetonitrileacetate + formate buffer, pH 2.5. Quality data were determined and were satisfactory The method detection hmitwas approximately 10 ng mL 1 for most of the quinolones studied. The proposed mobile phase is compatiblewith mass spectrometric detection of the substances.

Liquid chromatography?mass spectrometry approach for the characterization and purification of crude synthetic peptide hormones

“…2. This linearity has also been demonstrated in previous works for structurally different substances, obtaining different slopes which corre- ¬ spond to different structural regions of acetonitrile-water mixtures [21,22,23,24,25,26]. As all the data were obtained in one of the structural regions, the linear relationships obtained allow suitable prediction of the elution behaviour of peptide derivatives and hence optimisation of eluent composition from only two experimental measurements of k values for each analyte.…”

“…For the optimisation of the mobile phase composition, the linear solvation energy relationships (LSER) method, based on the single-solvent parameter was used as in previous works [21,22,23,24,25,26]. The linear relationship: (1) was applied to predict the retention of analytes at different acetonitrile percentages, between 25 and 35% (v/v), containing 0.1% (v/v) TFA.…”

“…Hence, the prediction of the elution profile of analytes on the basis of accurate quantitative relationships can be the basis for subsequent optimisation of the chromatographic conditions [15]. In previous studies the linear solvation energy relationship (LSER) methodology, based on the Kamlet-Taft multiparameter scale and on the scale of polarity [16,17,18,19,20], was used to predict the retention of series of peptides [21], quinolones [22,23], diuretics [24], anabolic steroids [25] and polyphenolic acids [26] in LC. This approach can be used to develop LC methodology to separate target peptides from other similar impurity peptide components, on the analytical scale and also on the preparative scale without lack of resolution.…”

Facile assay method for norfloxacin and ciprofloxacin by sequential injection chromatography

“…Literature survey on previous assay methods for NF and CF in various matrices has retrieved many methods using various analytical techniques. During the last 10 years, HPLC [14,[17][18][19][20][21][22][23][24][25][26][27], thin-layer chromatography [28], capillary electrophoresis [29][30][31][32], capillary electrochromatography [33], and enzymatic rotating biosensor-based [34] methods were reported.…”

Cathodic stripping voltammetry of pipemidic acid and ofloxacin in pharmaceutical dosages and human urine

“…The analytical procedures include atomic absorption spectrometry [3], colorimetry [4], flow injection spectrophotometry [5], spectrophotometry [6][7][8], microbiological assay [9], spectrofluorimetry [10][11][12], liquid chromatography [13][14][15][16][17], chemiluminance [18][19][20][21][22] and electroanalytical techniques [23][24][25][26][27][28][29].…”