柱切换RP-HPLC测定血浆中那格列奈的浓度

Determination of Nateglinide in human plasma by RP-HPLC with column switching technique

目的 建立测定血浆中那格列奈浓度的方法。方法 采用RP—HPLC法，LunaC18（2）分析柱（150mm×4．6mm，5μm）和大连装KromasilC18预处理柱（25mm×4．6mm，5μm），分析柱和预处理柱用流动相分别为0．025mol·L^-1磷酸-乙腈（58：42，氨水调pH6．6）和0．025mol·L^-1磷酸-乙腈（70：30，氨水调pH7．4），流速均为1．0ml·min^-1，样品血浆再加入pH2．1磷酸盐缓冲液。用二氯甲烷萃取浓集后进样，于210nm检测，以双氯酚酸作内标，按内标法定量。结果 标准曲线在0．025～16．000mg·L^-1范围内有良好的线性关系，最低定量限为0．025mg·L^-1，那格列奈和内标的保留时间分别为4．7、3．6min，分析方法的日内RSD〈6％，日间RSD〈10％，方法回收率90％～100％。结论 该法具有快速简便，灵敏准确等特点，适用于那格列奈血药浓度的测定。

OBJECTIVE To establish an RP - HPLC method with column - switching technique for the determination of Nateglinide （NG） in human plasma. METHODS Kromasil C18 pretreatment column（25 mm x 4.6 mm, 5 μm） and Luna Cs （2） analytical column （ 150 mm ×4. 6 mm, 51μm） were used. After being added pH 2. 1 phosphate buffer, the plasma sample was extracted with 3.5 ml dichloromethane. After evaporation of the organic layer, the residue was dissolved in mobile phase and injected onto the column. The mobile phase of 0. 025 mol·L^-1 phosphoric acid - acetonitrile（70 ： 30, pH7.4） and phosphoric acid - acetonitrile（58 ： 42, pH6. 6） were pumped at the rate of 1.0ml·min^-1 through the pretreatment and analytical column, respectively. The column - switching time was from 0. 8 min to 1.5 min. 210 nm wavelength was used. RESULTS The retention times of NG and internal standard were 4. 7 min and 3. 6 min, respectively. The standard curve was linear over the concentration range of 0. 025 to 16. 000 mg·L^-1. The lowest concentration of detection in plasma was 0. 025 mg·L^-1. The recovery of method was 90% - 100% with the intra - day RSD less than 6% and inter - day RSD less than 10%. CONCLUSION This method is simple, rapid, sensitive and accurate for determination of NG in human plasma.