An ultrasensitive method for the determination of thiouracil and phenylthiouracil using capillary zone electrophoresis and laser-induced fluorescence detection

Abstract

This paper reports the development of a method based on capillary electrophoresis with laser-induced fluorescence detection for the simultaneous determination of thiouracil (TU) and phenylthiouracil (PhTU) with high sensitivity (nanomolar range, i.e., attomoles detected). After derivatization with 5-iodoacetamidofluorescein, the analytes were separated by capillary zone electrophoresis using 20 mM phosphate buffer (pH 10.0) and quantified by fluorescence detection. The linearity range, precision, recovery, and detection limits were determined, and the method was shown to be applicable for the determination of TU and PhTU in spiked feed samples and urine.

Determination of thyreostatics in animal feeds by CE with electrochemical detector

“…Esteve-Romero et al, analyzed four thyreostatics (TU, MTU, PTU and PhTU) by MEKC with UV detector [22]. Recently, Perez-Ruiz reported using CE coupled with a laser-induced fluorescence detection to detect TU and PhTU in spiked feed samples and urine [23]. However, as we know, no one has used CE to separate all of the five commonly used thyreostatics drugs at the same time.…”

“…A lot of methods have been developed for the determination of thyreostatics residue in samples, such as highperformance thin layer chromatography [7], HPLC with ultraviolet (UV) or electrochemical or MS detection [8][9][10], GC with electron-capture or nitrogen-phosphorus or MS detection [11][12][13][14], our recently developed flow-injection analysis equipped with electrochemiluminescent detector [15], electrochemical analysis [16][17][18][19][20] and electrophoresis [21][22][23]. Although GC and HPLC are powerful analytical methods, they suffer from relatively high instrumental cost, use of too much samples and solvents, which may increase environmental burden, and too much time consumption.…”

Recent advances in the application of capillary electromigration methods for food analysis

“…CE methods have been successfully applied to the simultaneous determination of multiple illegal drugs in animal feeds [94,95]. In these works, 2-thiouracil and phenylthiouracil were derivatized with 5-iodoactamidofluoresceins prior to their analysis by CZE-LIF using a 20 mM disodium hydrogen phosphate at pH 10.0 [94].…”

“…In these works, 2-thiouracil and phenylthiouracil were derivatized with 5-iodoactamidofluoresceins prior to their analysis by CZE-LIF using a 20 mM disodium hydrogen phosphate at pH 10.0 [94]. Clenbuterol, cimaterio and salbutamol were analyzed by CZE-AD using a 150 mM borax-potassium dihydrogen phosphate at pH 6.0 [95].…”

Determination of phenothiazines in pharmaceutical formulations and human urine using capillary electrophoresis with chemiluminescence detection

“…There are some strategies to obtain lower detection limits such as the application of on-line preconcentration techniques [4,5] or the use of more sensitive detection systems, such as luminescence methods. Among them, LIF [6][7][8] has been widely used but chemiluminescence (CL) remains still unfamiliar although it has proved to be, in general, very sensitive in both flow-injection analysis (FIA) and HPLC because of its low background nature [9]. When combined with a versatile and efficient separation method such as CE, CL can offer excellent analytical sensitivity [10,11] and selectivity [12], allowing the resolution and quantification of various analytes in complex mixtures.…”