Microextraction of aromatic microbial metabolites by packed hypercrosslinked polystyrene from blood serum

The article is devoted to the application of modern sample preparation technique - microextraction by packed sorbent (MEPS) - in conjunction with non-conventional type of sorbent - hypercrosslinked polystyrene, that was investigated for the first time in this work. Their combination was used to extract phenylcarboxylic acid-type aromatic microbial metabolites from serum samples of a healthy volunteer with following derivatization and GC-MS detection. As barrel insert and needle for MEPS with hypercrosslinked polystyrene is not produced, we designed a device to imitate the commercial MEPS system with packed granular biporous hypercrosslinked polystyrene. Nine aromatic microbial metabolites, including sepsis associated phenyllactic, 4-hydroxyphenyllactic and 4-hydroxyphenylacetic acids, were extracted from serum samples (recoveries were 20-70%) and a linear dependence was revealed in the most clinically significant range of concentrations (0.5-18 μM). The results obtained demonstrate the perspective of the applying of hypercrosslinked polystyrene in commercial devices for MEPS for the future analyses of biological samples, in particular for the early diagnosis of sepsis and treatment effectiveness control.