Cloxacillin analysis

It has been recently reported (109) that use of both Penase and lactamase II hydrolysis and screening assays prior to chromatographic analysis can tentatively classify -lactams into three subgroups the first group includes a ceftiofur metabolite represented by desfuroyl-ceftiofur-cysteine the second, cephapirin and the third, penicillin G, ampicillin, amoxicillin, and cloxacillin. In this approach, portions of aqueous extracts of tissues are treated separately with Penase and lactamase II, and results are compared with those of untreated samples and positive controls. Bioactive ceftiofur metabolites are present, provided that the extracts retain inhibitory activity after Penase treatment but lose activity after lactamase II treatment and are positive in response to the immunochemical Lac-Tek-Cef test but negative to the Lac-Tek-Bl test (113). This approach can eliminate a large number of negative samples and, therefore, increases the efficiency of the assay. 

Ito, Y. Ikai, Y. Oka, H. Matsumoto, H. Kagami, T. Takeha, K. Application of ion-exchange cartridge clean-up in food analysis, in. Determination of henzylpenicillin, phenox3methylpenicilhn, oxacillin, cloxacillin, nafcillin, and dicloxacillin in hovine hver and kidney hy liquid chromatography with ultraviolet detection. J. Chromatogr., A 2000, 880, 85-91. 

Parker, C.E. Perkins, J.R. Tomer, K.B. Shida, Y. O Heu-a, K. Nanoscale packed capillary liquid chromatography-electrospray ionization mass spectrometry analysis of penicillins and cephems. J.Chromatogr., 1993, 616, 45-57 [capillary HPLC electrospray LC-MS serum also ampiciUin, car-benicUlin, cefalothin, cefazoUn, cefmenoxime, cefmetetzole, cefoperazone, cefotaxime, cefotiam, cefoxitin, cephalexin, cloxacillin, dicloxacillin, peniciUin G, pipericillin, sulbenicillin]... 

Salem, M.A.S. Alkaysi, H.N. High performance liquid chromatographic analysis and dissolution of ampicillin and cloxacillin in capsule formulation. Drug Dev.Ind.Pharm., 1987,13, 2771-2787 Hutchins, J.E. lyczkowska, K. Aronson, A.L. Determination of ampicillin in serum by using simple ultrafiltration technique and liquid chromatographic analysis. J.Assoc.Off Anal.Chem., 1986, 69, 757-759... 

Tyczkowska, K.L. Voyksner, R.D. Straub, R.F. Aronson, A.L. Simultaneous multiresidue analysis of 8-lactam antibiotics in bovine milk by liquid chromatography with ultraviolet detection and confirmation by electrospray mass spectrometry. JAOAC Int, 1994, 77, 1122-1131 [milk cow LC-MS electrospray UV detection LOD 10 ppb extracted ampicillin, ceftiofur, cephapirin, cloxacillin, penicillin G column temp 40]... 

Fig. 2 ESI LC/MS/MS analysis of penidUins fortified at a concentration of 0.05 mg/kg in bovine liver, a. Mass chromatograms monitored at [M-H-141] b, tandem mass spectra of penicillins recorded at the top of each peak on the mass chromatograms (a), (h-1) BenzylpeniciUin (b-2) phenoxymethylpeniciUin (b-3) oxacillin (b-4) cloxacillin (b-5) nafcUlin (b-6) dicloxacillin.

Desacetylcephapirin was extracted from milk samples and quantitated using a PLRP-S column (A = 290 nm) using a 16/84 acetonitrile/water (10 mM H3PO4 with lOmM KH2PO4 and lOmM sodium decanesulfonate) mobile phase [1379], This study also tabulated the conditions for the analysis of amoxicillin, ampicillin, cephapirin, ceftiofur, cloxacillin, and penicillins G and V. Again a C,g and an 30% acetonitrile/water (phosphate buffer) combination were used in each case. 

BenzylpenicUlin (PCG), phenoxymethylpeniciUin (PCV), oxacillin (MPIPC), cloxacillin (MCIPC), nafcilUn (NFPC), and dicloxaciUin (MDIPC), all of which are representative weakly acidic penicillins, are widely used as veterinary drugs for livestock. We have reported, in our previous studies, the applicability of sample cleanup with an ion-exchange cartridge, in combination with ion-pair HPLC, for the analysis of ionizable compounds. We therefore applied the same technique to develop an analytical method for the quantitative determination of these residual penicillins in bovine muscle, kidney, and liver. " ... 

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