Determination of enro?oxacin and its primary metabolite, cipro?oxacin, in pig tissues. Application to residue studies

Abstract

A simple and sensitive HPLC method has been developed for the simultaneous determination of enrofloxacin (ENR) and ciprofloxacin (CIP) in pig tissue using difloxacin (DIF) as internal standard. Tissue sample preparations were carried out by adding phosphate buffer (pH 7.4, 0.1 m), followed by extraction with trichloromethane. Fluoroquinolones were separated on a reversed-phase column and eluted with aqueous buffer solution-acetonitrile (80:20, v/v). The concentrations of CIP, ENR and DIF eluted from the column, with retention times of 2.20, 2.73 and 4.38 min, respectively, were monitored by fluorescence detection at lambda(ex) 276 and lambda(em) 442 nm. The detection and quantitation limit were 8 and 25 ng/g, respectively, for both compounds. Standard curves were linearly related to concentration in the range 25-400 ng/g. The consequences of the introduction of minor reasonable variations (ruggedness studies) have also been analysed. Finally, the measurement of the tissue levels of ENR and CIP in the pig tissues after oral administration confirmed the utility of the proposed method.

Clinical Efficacy and Residue Depletion of 10% Enrofloxacin Enteric-Coated Granules in Pigs

“…After 5 days of decontamination, the concentration of ENR and CP in each tissue were lower compared with MRL values regulated by the European Union 1 . Similar results were obtained in a previous study at a daily dose of 5 mg/kg ENR (5%) for 5 consecutive days (Garcia et al, 2005). However, in this study the administration dosage was 10 mg/kg EEG (10% ENR), which doubled that in previous work by Garcia (Garcia et al, 2005), but the ENR and CP concentrations were lower than the results by Garcia for the duration of the experiment.…”

“…Similar results were obtained in a previous study at a daily dose of 5 mg/kg ENR (5%) for 5 consecutive days (Garcia et al, 2005). However, in this study the administration dosage was 10 mg/kg EEG (10% ENR), which doubled that in previous work by Garcia (Garcia et al, 2005), but the ENR and CP concentrations were lower than the results by Garcia for the duration of the experiment. This result showed that 10% EEG had a faster elimination ratio in each tissue than Garcia's work.…”

Determination of quinolones residues in prawn using high-performance liquid chromatography with Ce(IV)–Ru(bpy)32+–HNO3 chemiluminescence detection

“…Methanol or acetonitrile often used in mobile phase were not compatible with many CL systems, but compatible with this CL system. Several mobile phases have been reported for the separation of QNs on a reversed phase column, such as acetonitrilewater [18,19,21,24,25], methanol-water [22], acetonitrilemethanol-water [17,23] and acetonitrile-tetrahydrofuran-water [20]. The ternary mixtures of acetonitrile-methanol-water (v/v/v) 3:15:82 were found to be suitable for good separation of these compounds and compatible with the CL system.…”

Ανάπτυξη Και Επικύρωση Μεθόδων Υγρής Χρωματογραφίας Υψηλής Πίεσης Για Τον Προσδιορισμό Κινολονών Σε Διάφορα Δείγματα Τροφίμων Ζωϊκής Προέλευσης Και Σε Φαρμακευτικά Σκευάσματα

“…Για το πρώτο στάδιο της εκχύλισης, στη βιβλιογραφία, χρησιμοποιούνται υπερκάθαρο νερό [91,111,119,130] και υδατικά διαλύματα, όπως διαλύματα NaOH [133,117,118], πυκνή αμμωνία [94,99,114,125,128,134] και διαλύματα HCl [96,97]. Επίσης χρησιμοποιούνται ρυθμιστικά διαλύματα σε pH 7.0 [94,131,133], pH 4.1 [127], pH 7.4 [103,110,112,122,132,136], pH 6.0 [129] και pH 9.1 [98].…”

“…Ακετονιτρίλιο [98-100, 104, 114, 116, 121, 125, 128], μεθανόλη [100], διχλωρομεθάνιο [91,92,109,117,121,130,132,133,136,137], εξάνιο [93,98,100,102,107,111,136], ακετόνη [102], χλωροφόρμιο [102,112,114] και ισοπροπανόλη [129] είναι οι συνηθέστεροι οργανικοί διαλύτες που χρησιμοποιούνται για την εκχύλιση των (φθορο)κινολονών από τα εξεταζόμενα υποστρώματα. Συχνά χρησιμοποιούνται διαλύματα των παραπάνω διαλυτών με κάποιο οξύ, όπως μίγμα μεθανόλης με οξικό οξύ [93,107,109], με φωσφορικό οξύ [108], με μίγμα φωσφορικού και υπερχλωρικού οξέος [106,113], διάλυμα αιθανόλης με οξικό οξύ [126] και διάλυμα CH 3 CN με άλας Na 2 SO 4 [95], με τριχλωρο-οξικό οξύ [101,111,120], με οξικό οξύ [104] και με φωσφορικό οξύ [115].…”