[Determination of serotonin in rat brain by gas chromatography/mass spectrometry]

A GC/MS method for the determination of serotonin (5-hydroxytryptamine, 5-HT) has been developed. 5-HT in homogenized rat brain was acylated and extracted into EtOAc. The acylate was further derivatized with heptafluorbutyl anhydride and formed a spirocyclic pentafluoropropionyl derivative. Subsequent analysis of 5-HT derivative by gas chromatography-electron capture negative ion chemical ionization mass spectrometry was highly specific and sensitive. The assay is linear from 0.5 to 50 micrograms/L with a linear equation of Y = 0.134 8X - 0.07995, r = 0.999. The recovery was 98.2% +/- 3.8% (n = 10) and the limit of detection was 0.5 microgram/L. The reproducibility of 5-HT determination in rat brain was less than 10% (RSD) at both levels of 1.0 microgram/L and 50.0 micrograms/L. The method has been applied to analysis of 5-HT in the dose rat brain successfully.