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Batch‐injection versus Flow‐injection Analysis Using Screen‐printed Electrodes: Determination of Ciprofloxacin in Pharmaceutical Formulations

“…Thed etermination of ciprofloxacin (structurei n Scheme 1) has been reported by different analytical methods, including high performance liquid chromatography (HPLC) [21][22][23][24],s pectrophotometry in the UV region [25,26],s pectrofluorimetry [27,28],a nd capillary electrophoresis [28][29][30][31].E lectroanalytical methods for ciprofloxacin determination have also reported using different working electrodes,s uch as mercury [ 32],c arbonpaste [32][33][34], boron-doped diamond [35,36],c arbon nanotubes [37][38][39], and graphene modified electrodes [40].T oo ur knowledge,t he use of screen-printed electroAbstract:T his article highlights the potential use of multi-walled carbon-nanotube modified screen-printed electrodes (SPEs) for the amperometric sensing of ciprofloxacina nd compares the association of batch-injection analysis (BIA)a nd flow-injection analysis( FIA) with amperometric detection. Both analytical systems provided precise (RSD < 5%)a nd sensitived etermination of cipro-…”

HPLC Separation of Nimesulide and Five Impurities using a Narrow-Bore Monolithic Column: Application to Photo-Degradation Studies

“…From a literature point of view, although there are numerous methods on the determination of nimesulide in pharmaceuticals using various techniques [18][19][20][21][22][23][24][25][26][27][28][29][30][31], to the best of our knowledge there are only two reports on the investigation of the photochemical stability of this API [32,33]. In 2003, Kovarikova and co-workers [32] exposed nimesulide to UV light (254 nm) and detected Imp D (2-phenoxy-4-nitroaniline) after 80 h. However, the HPLC method they developed had a separation cycle of more than 20 min without attempting the separation of the rest of the potential impurities described in the European Pharmacopoeia.…”

A simple spectrophotometric method for the determination of methyldopa using p-chloranil in the presence of hydrogen peroxide

“…Several methods have been proposed to quantify methyldopa in pharmaceutical formulations, including high-performance liquid chro- matography (HPLC) with UV detection [2][3][4][5], potentiometry [6], differential pulse polarography [7], titrimetry [8], UV [9,10] and visible spectrophotometry [11][12][13][14][15][16][17][18][19][20] and flow injection analysis (FIA) [21][22][23][24]. However, many of these methods are timeconsuming and/or require expensive equipment.…”

“…The visible spectrophotometric method recommended by the Brazilian Pharmacopeia for methyldopa tablets is based on the reaction with ferrous tartarate at pH 8.5 [11]. Other visible spectrophotometric methods involve the employment of diverse chromogenic reagents such as N-bromosuccinimide and isoniazid [12], barbituric acid [13], sodium nitroprusside in the presence of hydroxylamine hydrochloride [12], periodate in acidic medium [14], diazotized sulphanilamide in the presence of molybdate ions in acidic medium [15], p-dimethylaminocinnamaldehyde [16], vanillin in alkaline medium [17], cerium (IV) nitrate [18], ferric chloride in acidic medium [19], iron(III) in the presence of 1,10-phenanthroline and 2,2'-bipyridyl [20]. The methods by FIA with spectrophotometric detection involve the use of p-toluidine and sodium periodate [21], metaperiodate [22], p-aminophenol in alkaline medium [23] and ammonium molybdate [24] as chromogenic reagents.…”