Micellar Electrokinetic Chromatography of Cephalosporin Antibiotics

Abstract

A simple micellar electrokinetic chromatographic (MEKC) method is described for the simultaneous separation of twelve cephalosporin antibiotics. The separation was performed in a phosphate buffer (0.1 M, pH 6.6) with sodium dodecyl sulfate (SDS) (0.1 M) as an anionic surfactant. The complete separation of twelve cephalosporins was attained in 36 min. Application of the method to the quantitative analysis of cefuroxime, cephalexin, cephapirin and cephradine in pharmaceutical preparations was demonstrated.

Model and Imitation of the Cycle Temperature Fields and Deformations of Coke Drum

“…The fourth dimensional, time-dimensional, can be changed into the model's height by its moving speed with the time. The geometry scope of two-dimensional unsteady temperature field is T 0 D 1 D 3 T 3 [2][3], showed in Figure1.…”

“…After measure and calculation, it had been found that the three-dimensional temperature field is not only unfair, but also unsteady in each cycle operation. That is merely relative to the flow of kinetic medium and the measure method is not met with the theory completely [2][3][4]. Stress of circular weld of coke tower have showed that pressure stress on the angle distortion are the main factor of combined stress after compared with heat stress of steady state, residual stress, bend stress both of itself weight and wind load, if there is bulge and angle distortion [5].…”