A pre-column derivatization and ultra-
high performance liquid chromatography quadrupole
time-of-flight
mass spectrometry (UHPLC-QTOF-MS/MS)
method was developed for qualitative and quantitative
determination of medium- and
short-chain fatty acids in
mice feces, and was further applied to evaluate variations in the
feces of
mice before and after
antibiotic treatment. This
animal experiment had been approved by
Animal Experimental
Ethics Committee of Jiangsu Province
Academy of
Traditional Chinese Medicine. By optimizing the derivatization conditions and UHPLC-QTOF-MS/MS
parameters a new UHPLC-QTOF-MS/MS
method with 3-nitrophenylhydrazine as the derivatization
reagent was developed for simultaneous
determination of 16 medium- and
short-chain fatty acids.
Validation studies showed that the linearity of the
calibration curves was good (R2>0.99), the RSD of intra-day and inter-day precision was less than 10%, the repeatability RSD was less than 6%, the recovery rate was between 80% - 120% at three spiked levels, and the stability RSD was less than 7% within 36 h. The types and amounts of the detected medium- and
short-chain fatty acids in
feces significantly changed after the
mice were treated with
antibiotics. The content of formic
acid,
acetic acid, propionic
acid, butyric acid, isobutyric
acid, valeric
acid, and
lactic acid decreased, whereas that of heptanoic
acid and
succinic acid increased significantly. All these results suggest that the newly established
method is accurate and reliable, and can be used for
determination of medium- and
short-chain fatty acids in
feces.