LAUSR

Abstract In this study, we report for the first time developing an analytical method based on three metal–organic frameworks (MOF) including UiO-66, UiO-66-NH 2 and UiO-66-NH 2 @ Fe 3 O 4 -SiO 2 in micro-extraction by packed sorbent (MEPS) extracting trans, trans-muconic acid (tt-MA) in urine. The FT-IR, XRD and FE-SEM techniques were used for characterization of the synthesized MOFs. The effects of some analytical parameters were investigated on the MEPS performance using central composite design by response surface methodology. The findings demonstrated that the sample volume and desorption cycles were the most important parameters for the extraction of tt-MA using UiO-MEPS procedure combined with high-performance liquid chromatography (HPLC). The limit of quantification (LOQ) of UiO-MEPS-HPLC procedure for UiO-66, UiO-66-NH 2 and UiO-66-NH 2 @ Fe 3 O 4 -SiO 2 core–shell was 0.005, 0.005 and 0.003 µg mL −1 , respectively. Under optimal conditions, the UiO-MEPS-HPLC method offered a good performance for extracting tt-MA from urine samples (UiO-66, UiO-66-NH 2 and UiO-66-NH 2 @ Fe 3 O 4 -SiO 2 core–shell: 86%, 0.95% and 98.5%, respectively, RSD < 3.54%). The results indicated that this technique was a sensitive, fast and reusable method and can be applied to extract and determine trace amounts of urinary tt-MA in the urine matrix. Graphic abstract