Determination of Ciprofloxacin, the Major Metabolite of Enrofloxacin, in Milk by Isopotential Fluorimetry

Abstract

A new method for the determination of ciprofloxacin, the major metabolite of enrofloxacin, for concentrations between 20 and 200 ng/mL by means of matrix isopotential synchronous fluorescence spectrometry and derivative techniques is proposed. This new method is useful for the determination of compounds in samples with unknown background fluorescence, such as ciprofloxacin in whey, without the need of tedious preseparation. The determination was performed in an ethanol/water medium (20% v/v) at pH 4.8, provided by adding a sodium acetate/acetic acid buffer solution. Since enrofloxacin is widely used as an antibacterial agent in veterinary medicine, the method was successfully applied to the determination of its main metabolite in milk. An exhaustive statistical analysis has been developed to all calibration graphs. This treatment includes robust regression such as least median of squares, which also detects outliers and leverage points. The overall least-squares regression has been applied to find the more exact straight line that fits the experimental data. The error propagation has been considered to calculate the detection limit and the repeatability of the method.

Microchip capillary electrophoresis dairy device using fluorescence spectroscopy for detection of ciprofloxacin in milk samples

“…Therefore, the fluorescence spectroscopy technique is implemented with low-cost components, being an ultraviolet (UV) light emitting diode (LED) for the fluorescence excitation and a photodiode for the fluorescence detection, as in previous work 35 . As ciprofloxacin emits fluorescence at an excitation wavelength of 270 nm 36 , the UV LED for fluorescence excitation (VLMU60CL00-280-125 Vishay USA) is selected for its wavelength range of 270-290 nm and sufficient optical power of 2.4 mW. The UV LED is fixed on the UV LED printed circuit board (PCB).…”

“…The UV LED is fixed on the UV LED printed circuit board (PCB). As ciprofloxacin emits fluorescence at a wavelength of 440 nm 36 , an optical bandpass filter (86-339, Edmund Optics, USA) is selected for its passband wavelength range of 420-460 nm. There was an initial attempt to use an optical long pass filter (FGL435, Thorlabs USA), however, this optical long pass filter suffered from severe self-fluorescence.…”

A novel, selective, and rapid fluorimetric method for the simultaneous analysis of coproporphyrin and uroporphyrin in urine

“…However, most of them, either did not quantify CP and UP separately or the quantitative determination of the individual components of urinary porphyrins was achieved using expensive, tedious and time-consuming separation processes. Derivative Matrix Isopotential Synchronous Fluorescence Spectrometry (DMISFS) becomes a powerful technique for the multi-component analysis in the fields of analytical and biochemistry mainly because of its ability to resolve the spectra of closely overlapping mixtures [11][12][13][14][15][16][17][18]. In this technique, the scan of the synchronous fluorescence spectrum is proceeding through an isopotential trajectory, which connects points of equal intensity of a fluorescent matrix total fluorescence spectrum.…”

[The design of simple optical fiber laser polaristrobometer and DIY-spectropolarimeter for multivariate analysis of milk & diary products properties. Part I.]

“…ми флуориметрии [85][86][87], необходимо придание конструируемой установке возможностей анализа поляризации флуоресценции. Давно известно, что излучение люминесценции при возбуждении естественным светом может являться частично поляризованным, если распределение возбуждающего светового вектора в плоскости, перпендикулярной линии наблюдения, является анизотропным [88].…”