Abstract: AIM: To establish a highly sensitive, rapid and selective liquid chromatography-tandem mass spectrometry (LC-MS MS) method to determinate the viaminate in bile, urine and feces sample of rats .And to study the excretion of viaminate in rats in order to provide a guidance for the clinical trial .METHODS: The concentration of viaminate was determinated on an Aglilent TC C18 column and the mobile phase consisted of methanol-water and formic acid (93 ∶7 ∶0 .1, V/V/V) using simvastatin as internal standard .The de-tection was performed on a trip-quadrupole tandem mass spectrometer by selected ion monitoring (SRM) scan mode via atmospheric pressure chemical ionization (APCI) .The detected ions were m z 448 283 (viami-nate) and m z 419 285(internal standard) respective-ly.The accumulative excretion amount of viaminate was calculated in the urine, feces and bile, respectively.RESULTS: The extraction recoveries of viaminate in bile, urine and feces were more than 89 %.The RSD of intra-run and inter-run precisions were all less than 10 %.The calibration curves were linear over the con-centration ranges of 0 .0808 -40 .4 ng mL(r =0 .9972 and 0 .9949) for the viaminate in bile and urine .The calibration curve was linear over the concentration ranges of 0 .505 -50 .5 ng mL (r =0 .9990) for the viaminate in feces, The limit of quantitation of method for viaminate was 0 .2 pg .12 .9 %viaminate was found from feces in 72 hours, 0 .003 %was found from urine in 96 hours and 0 .0001 %was detected from bile in 24 hours.CONCLUSION: The method is proved to be accurate, sensitive, selective and convenient .It has successfully been applied to study the excretion of vi-aminate in rats .The amount of viaminate recovered from bile and urine after orally administrated to rat was very low .

Key words: viaminate, liquid chromatography-at-mospheric pressure chemical ionization-tandem mass spectrometry, excretion