Objective     To establish a sensitive and accurate gas chromatography-mass spectrometry method for determination of quinolinic acid in rat serum.      Methods     The objective compound was purified and derivatized to its dihexafluoroisopropyl ester before quantitative determination by scanning method and quantitative determination by SIM method.      Results     The endogenous substances in serum had no interference on the measurement of quinolinic acid in the sample. Assay linearity was obtained in the range of 0.05-20 μmol/L with limit of quantitation (LOQ) of 0.05 μmol/L. The intra-day relative standard deviation (RSD) was lower than 15%. The inter-day relative standard deviation was lower than 12%.      Conclusion     It is a sensitive

accurate and convenient method. The dihexafluoroisopropyl ester of quinolinic acid is quite stable

but the serum should not be preserved for a long time before derivation.