Electrochemically deposited conductive composite sorbent for highly efficient online solid-phase microextraction of jasmonates in plant samples

Conductive composite films composed of poly (3, 4-ethylenedioxythiophene) (PEDOT) and sulfonated graphene were electrochemically deposited on carbon fiber bundle in aqueous solutions for solid phase microextraction (SPME). During the electro-polymerization process, negatively charged sulfonated graphene were doped in PEDOT layer and uniformly dispersed in the composite. The modified carbon fiber bundle worked as sorbent was then successfully applied to online SPME-HPLC-UV analysis of jasmonates in wintersweet flowers. High extraction efficiency (over 420-fold), low limits of detection (0.1 ng for jasmonic acid and 0.01 ng mL(-1) for methyl jasmonate) and wide linear ranges (0.5-5000 and 0.05-5000 ng mL(-1), R>0.9997) have been obtained. It has been demonstrated that this method can be well used for jasmonates analysis in fresh wintersweet flowers with good recoveries (92.4-98.9%). The results were confirmed by HPLC-MS method.