[Hydrophilic interaction liquid chromatography coupled with mass spectrometry for metabolomic analysis of Escherichia...

The zwitterionic hydrophilic interaction liquid chromatography coupled with mass spectrometry (ZIC-HILIC/MS) method was developed and applied for studying the metabolome of Escherichia coli. In this method, the linear ranges of the 52 representative compounds were between 2-6 orders of magnitude. Moreover the lowest limits of detection of most compounds were at ng/mL levels. The analysis for six samples prepared in parallel showed that the method had good reproducibility with more than 85% metabolites with the RSDs of peak area less than 30%. The precision of the method was tested by evaluating the relative recoveries of six internal standards at the low, middle and high concentrations. The results exhibited that the intraday precisions (RSDs) of the six compounds in the same concentrations were less than 20%. The recoveries of most compounds were accepted in the range of 70%-130%. The results of metabolomic analysis of three Escherichia coli strains with genetic modified yfcC gene showed that some small peptides, amino acids, nucleosides, organic acids and phospholipids changed differentially after the yfcC gene modification. These results indicated that the ZIC-HILIC/MS method could detect diverse metabolites and be used for metabolomic analysis purpose with good reproducibility and stability.