Magnetic porous carbon derived from Zn/Co metal–organic framework as an adsorbent for extraction and determination of carbamates

A novel magnetic porous carbon with a high specific surface and magnetization saturation, derived from a Zn/Co-MOF-5, was fabricated by direct carbonization of Zn/Co-MOF-5 without the need of additional carbon precursors under optimum pyrolysis temperature. The material was employed as an adsorbent for magnetic solid-phase extraction of four carbamates from water and tomato samples prior to high-performance liquid chromatography–tandem quadrupole mass spectrometry analysis. Under optimum conditions, the method displayed good linearity ( r  > 0.9987) within the concentration range 0.05–20 ng mL −1 for water samples and 0.1–40 ng g −1 for tomato samples. The limits of detection (S/ N  = 3) for the four carbamate pesticides were in the range 0.0006–0.013 ng mL −1 for water samples and 0.001–0.01 ng g −1 for tomato samples and satisfactory spiked recoveries in the range 86.1 to 109.1% were obtained with the relative standard deviation values from 2.1 to 14.0%. Graphical abstract