title: [Determination of endogenous agmatine in rat plasma by isotope dilution-gas chromatography-mass spectrometry].
abstract: 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.
authors.forename: Zhongli
authors.initials: Z
authors.lastname: Qiu
authors.forename: Ying
authors.initials: Y
authors.lastname: Lin
authors.forename: Zhili
authors.initials: Z
authors.lastname: Xiong
authors.forename: Jianwei
authors.initials: J
authors.lastname: Xie
mesh_terms: D000376:Agmatine / Q000097:blood*; D000818:Animals; D002849:Chromatography, Gas; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D007554:Isotopes; D057230:Limit of Detection; D008297:Male; D013058:Mass Spectrometry; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D007554:Isotopes; D000376:Agmatine