Determination of sulfadiazine in Jiaozhou Bay using molecularly imprinted solid-phase extraction followed by high-performance liquid chromatography with a diode-array detector

• The sulfadiazine molecularly imprinted polymer (SDZ-MIP) was prepared.
• The characteristics and recognition efficiency of MIP were studied.
• An off-line method for SDZ was developed using MIP as solid-phase extraction sorbent.
• Seven seawater samples were determined from Jiaozhou Bay, Qingdao.
• The SDZ concentrations in two seawater samples were 0.33 and 0.28 μg L−1.

A highly selective sample cleanup procedure featuring molecularly imprinted solid-phase extraction (MISPE) was developed for the isolation and determination of sulfadiazine (SDZ) in seawater samples from Jiaozhou Bay, China. The molecularly imprinted polymer (MIP) was prepared using SDZ as the template molecule and methacrylic acid as the functional monomer. The MIP was used as a selective sorbent for the solid-phase extraction of SDZ. An off-line MISPE method followed by high-performance liquid chromatography (HPLC) with diode-array detection was established for the analysis of SDZ. Good linearity of the MISPE column for SDZ standard solutions was obtained within 0–200 μg L−1 (R2 > 0.99). The recoveries of spiked seawater samples were satisfactory as high as 88%. Finally, seven samples in Jiaozhou Bay were determined and there was no sulfadiazine found except #2 and #5 sample. The concentrations were respectively 0.33 μg L−1 and 0.28 μg L−1, and the relative standard deviations were 1.35% and 4.13% (n = 3).