Analysis of strong polar compounds in extract of Gardenia jasminoisdes fruit using hydrophilic interaction liquid chromatography with evaporative light-scattering detection

The hydrophilic interaction liquid chromatography (HILIC) is an alternative HPLC mode for separation of polar compounds with polar stationary phases like NP-HPLC but aqueous mobile phase similar to RP-HPLC mode. Evaporative light-scattering detection (ELSD) is an important detector when UV detection is not feasible. The ELSD has been shown to successfully detect many substances such as phospholipids, triglycerides, fats and fatty acid esters, carbohydrates, synthetic polymers, steroids, amino acids and inorganic ions, such as chloride and sodium cations. In this study the fraction eluted at 2-3min in RP-HPLC of crude extract of Gardenia jasminoisdes fruit was collected and separated by the combination of HILIC with ELSD through study the effect of formic acid and the content of formic acid in mobile phase. The mobile phase was prepared using two solutions, A and B, where A was 0.5% (V/V) formic acid in water, and B was 0.5% (V/V) formic acid in acetonitrile solution. The analytes were eluted from the column with a linear gradient of 10% A to 40% A over 30 minutes and holding 40%A for 5 minutes. The chromatography of strong polar compounds of fruit of Gardenia jasminoisdes is shown in Fig 1. The precision of retention time of the method was determined by injecting six times. Except peak 2 all the RSD were less than 0.13% and the RSD of peak 2 was 0.22%. The retention mechanism of peak 1 and 3 was also studied. The result indicated that the mechanisms of the two peaks were HILIC mode and it can be regressed with the equation: lnk’=a+blnCB+cCB with an average R2 of 0.9999 for peak1 and 0.9953 for peak 3