柱切换-反相高效液相色谱法测定血浆中沙丁胺醇浓度

目的　采用柱切换对反相高效液相色谱法测定血浆中沙丁胺醇浓度的方法进行改进。方法　采用Ultrasphere CN色谱柱 ( 2 5 0× 4.6m m,5μm )和 Krom asil C1 8( 2 0× 4m m,5μm )预处理柱 ,分析和预处理柱均以p H 2 .8、0 .0 2 5 mol/L磷酸盐缓冲液∶乙腈∶甲醇 ( 95∶ 4∶ 1)为流动相 ,吗啡作内标。血浆样品加入含二苯基硼酸 - 2 -氨基乙脂的缓冲液 ( p H 9.0 )后 ,用含四辛基溴化铵的氯仿萃取 ,再用 0 .0 8m ol/L醋酸 3 0 0μl反萃 ,取酸液10 0μl进样 ,预处理柱 0 .7～ 1.5 m in流出组份进入分析柱分析 ,2 2 4nm波长下检测 ,按内标法定量。结果　标准曲线线性范围为 0 .5～ 3 2μg/L ,最低定量限为 0 .5μg/L ,沙丁胺醇和内标的保留时间分别为 6.7min和 7.6m in,日内 RSD小于 5 % ,日间 RSD小于 8% ,萃取回收率大于 80 % ,方法回收率在 96%～ 10 7%。结论　本法具有快速简便 ,灵敏准确等特点 ,适用于沙丁胺醇血药浓度测定及药代动力学、生物利用度研究用

Determination of Salbutamol in Human Plasma by Column-switching HPLC with UV Detection

OBJECTIVE: To make better the RP-HPLC method with column-switching technique for the determination of salbutamol in human plasma. METHODS: A high-pressure flow channel selection valve and Kromasil C18 pretreatment column (20 x 4 mm, 5 microns), Ultrasphere Cyano analysis column (250 mm x 4.6 mm, 5 um, Beckman) were used. To the plasma sample 1.0 ml, 0.5 ml phosphate buffer (2.0 mol/L, pH 9.0) containing 0.4% diphenylboric acid 2-aminoethyl ester was added, then extraction was performed with the use of 4.0 ml chloroform containing 1% tetraoctylammonium bromide. The organic layer was removed and extracted again with 300 microliters (0.08 mol/L) acetic acid. 100 microliters of the acid layer was injected onto the column. The mobile phase of pH 2.8, 0.025 mol/L phosphate buffer-acetonitrile-methanol (95:4:1) was pumped at the rate of 0.9 and 1.0 ml.min-1 through the pretreatment and analysis column, respectively. The column-switching time was from 0.7 min to 1.5 min. The detector at 0.002 aufs was set at 224 nm. RESULTS: The retention time for salbutamol was 6.7 min and that for internal standard (morphine) 7.6 min. The standard curve was linear over the concentration range from 0.5 to 32 micrograms/L. The lowest concentration of detection in plasma was 0.5 microgram/L. The method recovery was 96%-107%; the intra-day RSD less than 5%; the inter-day RSD less than 8%. CONCLUSION: This method was found to be simple, rapid, sensitive and accurate for determination of salbutamol in human plasma.