Front Cover: Sol‐gel niobia sorbent with a positively charged octadecyl ligand providing enhanced enrichment of nucleotides and organophosphorus pesticides in capillary microextraction for online HPLC analysis

Abstract

J Sep Sci 2018, 41, 1663–1673 DOI: https://doi.org/10.1002/jssc.201701104 The cover picture shows sol‐gel capillary Microextraction (CME) using a novel niobia‐based sol‐gel sorbent coating chemically bonded to the inner surface of a fused silica capillary online coupled to HPLC. The sol‐gel niobia sorbent provides efficient extraction of organophosphates (including organophosphorus pesticides and nucleotides) by simultaneously providing Lewis acid‐base‐, electrostatic‐, and van der Waals interactions. Chemical bonding of the sol‐gel coating to capillary wall makes it solvent‐resistant a feature critically important for successful online hyphenation of a microextraction technique to a liquid‐phase separation system like HPLC.