Hollow fiber-based liquid–liquid–liquid micro-extraction with osmosis: II. Application to quantification of endogenous gibberellins in rice plant

Abstract

The phenomenon and benefits of osmosis in hollow fiber-based liquid–liquid–liquid micro-extraction (HF-LLLME) were theoretically discussed in part I of this study. In this work, HF-LLLME with osmosis was coupled with high performance liquid chromatography–triple quadrupole mass spectrometry (HPLC–triple quadrupole MS/MS) to analyze eight gibberellins (gibberellin A1, gibberellin A3, gibberellin A4, gibberellin A7, gibberellin A8, gibberellin A9, gibberellin A19 and gibberellin A20) in rice plant samples. According to the theory of HF-LLLME with osmosis, single factor experiments, orthogonal design experiments and mass transfer simulation of extraction process were carried out to select the optimal conditions. Cyclohexanol – n-octanol (1:3, v/v) was selected as organic membrane. Donor phase of 12mL was adjusted to pH 2 and 20% NaCl (w/v) was added. Acceptor phase with an initial volume of 20μL was the solution of 0.12molL−1 Na2CO3–NaHCO3 buffer (pH 9). Temperature was chosen to be 30°C and extraction time was selected to be 90min. Under optimized conditions, this method provided good linearity (r, 0.99552–0.99991) and low limits of detection (0.0016–0.061ngmL−1). Finally, this method was applied to the analysis of endogenous gibberellins from plant extract which was obtained with traditional solvent extraction of rice plant tissues, and the relative recoveries were from 62% to 166%.