Automatic hyphenated analytical techniques hold great promise for reducing labour intensity, enhancing efficiency, and ensuring data reproducibility. In recent decade, Boronate affinity solid phase microextraction (BA-SPME) has emerged as a unique tool for the selective extraction of cis-diol-containing compounds. However, automatic hyphenation of SPME with high performance liquid chromatography (HPLC) has not yet been reported. Herein we report a new automated hyphenation of in-tube BA-SPME with HPLC for the determination of cis-diol compounds in tea beverages. The automated hyphenation was implemented through a flow-switch via the six-way valve of an autosampler. We prepared an in-tube SPME capillary, investigated the loading capacity of the coated column, characterized the morphology of the column, and investigated the factors influencing the separation. Finally, using the automatic hyphenated SPME-HPLC approach, we analyzed the cis-diol-containing compounds in three kinds of commercial tea beverages and investigated the effect of tea-making temperature on the content of the cis-diol-containing compounds in the prepared tea.
Keywords: automated on-line hyphenation; boronate affinity; cis-diol compounds; liquid chromatography (LC); solid phase microextraction (SPME); tea beverage.