Balanced extraction of volatile and semi-volatile compounds by dynamic linked position unity solid-phase microextraction

Although the compound profiles in extracts are linked to the solid-phase microextraction (SPME) position (headspace or liquid), a theoretical interpretation of this scenario has not yet been provided. In this study, the dynamic linked position unity (DLPU)-SPME is proposed as a method that allows balanced extraction of volatile and semi-volatile compounds. Furthermore, the pH, temperature, and salt were confirmed as the key factors affecting the extraction efficiency of DLPU-SPME. Theoretical calculations indicated that Kfs0Kfs is a key factor directly indicating the SPME extraction position (Kfs0Kfs > 1, headspace; Kfs0Kfs = 1, any position; Kfs0Kfs < 1, in liquid), while the target analytes determined that VhKhs+VsVeKfhKhs regulates the effect of the extraction position on the extracted amount. The proposed DLPU-SPME method containing both extraction positions (i.e., headspace and liquid) can simultaneously extract volatile and semi-volatile compounds, thus avoiding extraction bias.