Yamamoto E, Murata K, Ishihama Y, Asakawa N
Analytical Research Laboratories, Eisai Co., Ltd., Tsukuba, Ibaraki, Japan.
Anal Sci. 2001 Oct;17(10):1155-9. doi: 10.2116/analsci.17.1155.
We evaluated a new restricted access media (RAM) precolumn for direct analysis of drugs in plasma using a column switching HPLC system. The new RAM material was prepared by the modification of the external surface of porous silica with hydrophilic methylcellulose (MC), followed by modification of the internal surface with octadecylsilane (ODS). The external surface of the MC-immobilized ODS silica material (MC-ODS) suppressed the adsorption of proteins, while the internal surface of MC-ODS retained various types of drugs, such as ketoprofen, propranolol, caffeine and atenolol in plasma samples. In addition, MC-ODS allowed direct analysis of drugs in a 1000-microL plasma sample to monitor trace amounts of analytes contained. Reduced efficiency and clogging of the MC-ODS precolumn and/or the analytical column were not observed even after the repetitive injection of plasma sample up to 40 mL. Our results indicated that the MC-ODS precolumn could be used in pharmacodynamic and clinical studies.
我们评估了一种新型受限进样介质（RAM）预柱，用于使用柱切换高效液相色谱系统直接分析血浆中的药物。新型RAM材料是通过用亲水性甲基纤维素（MC）修饰多孔硅胶的外表面，然后用十八烷基硅烷（ODS）修饰内表面制备而成。固定有MC的ODS硅胶材料（MC-ODS）的外表面抑制了蛋白质的吸附，而MC-ODS的内表面保留了血浆样品中的各种药物，如酮洛芬、普萘洛尔、咖啡因和阿替洛尔。此外，MC-ODS允许直接分析1000微升血浆样品中的药物，以监测其中所含痕量分析物。即使重复进样高达40毫升血浆样品后，也未观察到MC-ODS预柱和/或分析柱的效率降低和堵塞情况。我们的结果表明，MC-ODS预柱可用于药效学和临床研究。
