کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1217749 | 1494178 | 2007 | 6 صفحه PDF | دانلود رایگان |

We present a method for determining two cephalosporins (cefoperazone and ceftiofur) in plasma by on-line solid-phase extraction (SPE)—capillary zone electrophoresis (CZE) with a T-split interface. Using this interface, a part of the SPE elution plug containing the cephalosporins is injected while the rest of the sample is flushed to waste. SPE was carried out using a C18 micro-precolumn and the cephalosporins presented good retention properties with breakthrough volumes above 1 ml. Using a desorption volume of 426 nl of acetonitrile, recoveries were 75 and 90%, for cefoperazone and ceftiofur, respectively. The resulting elution volume was about 1.8 μl. A deproteinization step was included prior to SPE for the analysis of plasma samples with recoveries of 90 and 57% for cefoperazone and ceftiofur, respectively. With UV detection at 254 nm, linear relationships between the injected concentration and peak area was measured between 10 and 500 ng ml−1 for standards, and 200 and 1500 ng ml−1 for plasma samples. Intra-day (n = 5) and inter-day (n = 5) peak area repeatability were lower than 12% RSD. The detection limits obtained for spiked plasma (100 ng ml−1 cefoperazone and ceftiofur) are sufficient for applying the method to pharmacokinetic studies.
Journal: Journal of Chromatography B - Volume 856, Issues 1–2, 1 September 2007, Pages 365–370