Recent development in sample preparation techniques for plant hormone analysis

Plant hormones are a variety of trace endogenous compounds, playing vital role in plant growth, development and quick response to biotic and abiotic stresses. Precise plant hormone analysis contributes to a better understanding of the regulating network of plant hormone signaling, however, due to the instability and ultra-trace amounts of plant hormones, it is important to select an appropriate pre-treatment method to enrich the intended analytes from the complex plant matrices. Herein, recent advanced sample preparation methods for endogenous plant hormone analysis in the past five years are reviewed and summarized according to different extraction modes. Besides, the emerging chemical labelling approaches that enable to improve the sensitivity are also introduced. In the end, the future trends of plant hormone analysis are taken into discussion. We believe the perspective may serve as guidance for the research of plant hormones in the analytical, environmental and botanical fields.