犬血浆中甘草次酸及异甘草酸镁的LC-MS法测定

Determination of Glycyrrhetic Acid and Magnesium Isoglycyrrhizinate in Dog Plasma by LC-MS

建立了LC-MS法测定Beagle犬血浆中的甘草次酸及异甘草酸镁。血浆样品经固相萃取,采用C18色谱柱,以10mmol/L乙酸铵溶液(pH7.3)和乙腈为流动相进行梯度洗脱,以齐墩果酸为内标,选择性离子监测质核比(m/z)469.00(甘草次酸)、821.40(异甘草酸镁)和455.40(内标)。甘草次酸和异甘草酸镁分别在10～500ng/ml和30～3000ng/ml浓度范围内线性关系良好,日内、日间RSD均小于15%。

A LC-MS method was established for the determination of glycyrrhetic acid and magnesium isoglycyrrhizinate in Beagle dog plasma. The plasma samples were extracted by solid phase extraction. A C18 column was used with the mobile phase of 10mmol/L ammonium acetate solution （pH7.3） and acetonitrile with gradient elution. Oleanolic acid was used as the internal standard. A selected ion monitoring （SIM） mode was chosen for the detection of m/z 469.00 （glycyrrhetic acid）, 821.40 （magnesium isoglycyrrhizinate） and 455.40 （internal standard）. The calibration curves of glycyrrhetic acid and magnesium isoglycyrrhizinate were linear in the concentration range of 10-500ng/ml and 30-3000ng/ml, respectively. The RSDs of intra- and inter-days were less than 15 %.