Viñas P, Campillo N, López-Erroz C, Hernández-Córdoba M
Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, Spain.
J Chromatogr B Biomed Sci Appl. 1997 Jun 6;693(2):443-9. doi: 10.1016/s0378-4347(97)00075-3.
Ranitidine and its main metabolites, ranitidine N-oxide and ranitidine S-oxide, were determined in plasma and urine after separation using reversed-phase liquid chromatography. The mobile phase consisted of an initial isocratic step with 7:93 (v/v) acetonitrile-7.5 mM phosphate buffer (pH 6) for 8 min, followed by a linear gradient up to a 25:75 (v/v) mixture over 1 min. Detection was carried out by a post-column fluorimetric derivatization based on the reaction of the drugs with sodium hypochlorite, giving rise to primary amines that reacted with o-phthalaldehyde and 2-mercaptoethanol to form highly fluorescent products. The calibration graphs, based on peak area, were linear in the range 0.1-4 microg/ml for all drugs. The detection limits were 30, 41 and 32 ng/ml (8.6, 12.5 and 9.1 pmol) for ranitidine S-oxide, ranitidine N-oxide and ranitidine, respectively. Chromatographic profiles obtained for plasma and urine samples showed no interference from endogenous compounds.
采用反相液相色谱分离后，测定了血浆和尿液中的雷尼替丁及其主要代谢产物雷尼替丁N -氧化物和雷尼替丁S -氧化物。流动相初始为等度洗脱，采用7:93（v/v）乙腈 - 7.5 mM磷酸盐缓冲液（pH 6），持续8分钟，随后在1分钟内线性梯度至25:75（v/v）混合液。通过柱后荧光衍生化进行检测，该衍生化基于药物与次氯酸钠的反应，生成与邻苯二甲醛和2 -巯基乙醇反应形成高荧光产物的伯胺。基于峰面积的校准曲线在所有药物的0.1 - 4 μg/ml范围内呈线性。雷尼替丁S -氧化物、雷尼替丁N -氧化物和雷尼替丁的检测限分别为30、41和32 ng/ml（8.6、12.5和9.1 pmol）。血浆和尿液样本获得的色谱图显示无内源性化合物干扰。
