A spherical metal-organic coordination polymer for the microextraction of neonicotinoid insecticides prior to their determination by HPLC

The authors describe a new spherical metal-organic coordination polymer (MOCP) for use as an adsorbent in solid-phase microextraction (SPME). By applying the ions Co(II), Fe(II), Cu(II), and Zn(II) in these polymers, MOCP with different morphology were obtained. The respective coatings for SPME display different extraction efficiency towards neonicotinoid insecticides (neo-nics). The Co(II)@MOCP coating displays an improved extraction capability for neo-nics when compared to the four commercially available coatings studied. Following extraction with the Co(II)@MOCP-coated fiber, the neo-nics were eluted using 1 mL of trifluoroacetic acid/acetonitrile solution and quantified by high performance liquid chromatography. The method, when applied to spiked honey samples, has good linearity (0.5-600 μg kg^-1) and a low limit of detection (0.05-0.15 μg kg^-1). The precision (n = 6) for a single fiber was in the range of 3.6-8.3%. The reproducibility (for n = 5) from fiber-to-fiber ranges between 5.4 and 8.8%. The Co(II)@MOCP-coated fiber can be reused more than 80 times without any apparent reduction in its performance. In addition, the relative recoveries from spiked honey samples are very good (91.5%-103.5%). Graphical abstract A spherical metal-organic coordination polymer (MOCP) was synthesized under the regulation of Co(II) and used for the solid-phase microextraction (SPME) of neonicotinoid insecticides found in honey.