Open‐tubular capillary electrochromatographic determination of ten sulfonamides in tap water and milk by a metal‐organic framework‐coated capillary column

In this study, a metal‐organic framework (MOF), [Mn(cam)(bpy)], was synthesized and characterized by thermogravimetric analysis, scanning electron microscopy, and Fourier transform infrared spectrometry. An open‐tubular capillary column was fabricated from [Mn(cam)(bpy)] via the amide coupling method. Ten types of sulfonamides were separated through the fabricated capillary column, which showed a good limits of detection (<0.07 μg/mL) and linear ranges (1–100 or 5–100 μg/mL) with a high correlation coefficients (R² > 0.9987). The intra‐day, inter‐day and column‐to‐column relative standard deviations (RSDs) in the migration times ranged from 0.44 to 4.87%, and the peak area RSDs ranged from 0.80 to 7.28%. The developed capillary electrochromatography method can be successfully utilized for the determination of sulfonamides in tap water and milk samples.