الملخص الإنجليزي
A novel, rapid, economic, sensitive and environmentally friendly chemilumine scence (CL) microfluidic system has been developed for the determination of cetrizine hydrochloride (CET) and levofloxacin (LEV) in pharmaceutical and biological samples. The CL method is based on the oxidation of tris (2, 2 bipyridyl)ruthenium(II) by peroxydisulphate in a two chip device. For CET, three instrumental setups were tested in order to find the most economical, sensitive and high throughput setup. In the first setup, a continuous flow of sample and CL reagents was used, whereas in the second setup, a fixed volume (2 uL) of (Ru(bipy)344) was introduced into a continuous infusion of peroxydisulphate and the sample. In the third design, a fixed volume of sample (2 uL) was injected while the CL reagents were continuously infused. The CL signal was enhanced 200 % when the third setup was used compared to the other two setups. Up to 180 samples of CET can be analyzed in an hour consuming minute quantities of reagents. In order to increase the sample throughput further, parallel analysis was carried out for the analysis of LEV. Up to 720 samples of LEV can be analyzed in an hour. Various parameters that influence the CL signal intensity were optimized. Under the optimum conditions, a linear response was obtained for the range of 50 ug L to 6400 ug L-1 and 100 ug Ľ" to 7000 ug L-' for CET and LEV respectively. The detection limit was found to be 15 ug L (S/N = 3) for CET and 44 ug - and 64 ug L-?for the two detectors of LEV respectively (S/N = 3). The amount of consumed sample was only 2 uL, from which the detected amount of CET was found to be 6.5 x 10-14 mol and 2.4 x 101 mol and 3.5x 10 mol respectively for the two detector of LEV. This procedure was successfully applied to the analysis of CET and LEV in pharmaceutical formulations and biological fluids.
