Qiu Zhongli, Lin Ying, Xiong Zhili, Xie Jianwei
Se Pu. 2014 Jul;32(7):779-83. doi: 10.3724/sp.j.1123.2014.03030.
A method for the determination of endogenous agmatine in rat plasma was developed by isotope dilution-gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS). The plasma samples were analyzed after protein precipitation, evaporation, derivatization by hexafluoroacetone (HFAA), and clean-up on a Florisil SPE column. The GC-MS analysis utilized stable isotope d8-agmatine as internal standard. The samples after treatme were tested by negative chemical ionization with selected ion monitoring (SIM) which was set at m/z 492 (molecular ion of agmatine) and m/z 500 (molecular ion of internal standard). The limit of detection (LOD) of agmatine standard solution was 0.005 7 ng/mL. The calibration curve of the agmatine spiked in rat plasma showed a good linear relationship at the range of 1.14-57.0 ng/mL (r = 0.997). The recoveries of agmatine spiked in rat plasma ranged from 92.3% to 109.8%. Inter-day and intra-day precisions were less than 15%. The average concentration level of agmatine in rat plasma was (22 +/- 9) ng/mL, and there was no significant difference between male and female SD rats (p > 0.05). The method is high sensitive and specific, and can be used for the determination of endogenous agmatine in plasma. It provides a strong support for the subsequent research of agmatine.
采用同位素稀释-气相色谱-负化学电离质谱法（GC-NCI/MS）建立了大鼠血浆中内源性胍丁胺的测定方法。血浆样品经蛋白沉淀、蒸发、六氟丙酮（HFAA）衍生化以及在弗罗里硅土固相萃取柱上净化后进行分析。GC-MS分析以稳定同位素d8-胍丁胺作为内标。处理后的样品通过负化学电离和选择离子监测（SIM）进行检测，SIM设置在m/z 492（胍丁胺分子离子）和m/z 500（内标分子离子）。胍丁胺标准溶液的检测限为0.005 7 ng/mL。大鼠血浆中加标胍丁胺的校准曲线在1.14 - 57.0 ng/mL范围内呈良好线性关系（r = 0.997）。大鼠血浆中加标胍丁胺的回收率在92.3%至109.8%之间。日间和日内精密度均小于15%。大鼠血浆中胍丁胺的平均浓度水平为（22±9）ng/mL，雄性和雌性SD大鼠之间无显著差异（p > 0.05）。该方法具有高灵敏度和特异性，可用于血浆中内源性胍丁胺的测定。为后续胍丁胺的研究提供了有力支持。
