Determination of organophosphorus in dairy products by graphitic carbon nitride combined molecularly imprinted microspheres with ultra performance liquid chromatography

Organophosphorus (OPPs) residues in dairy products are a potential threat to human health. To extract trace amounts of OPPs in dairy products, a graphitic carbon nitride (g-C(3)N(4)) was synthesized and combined with OPPs-based molecularly imprinted microspheres (MIM) to create a composite material (MIM/g-C(3)N(4)). Then, the MIM/g-C(3)N(4) was used to prepare a solid phase extraction (SPE) cartridge to detect the OPPs in dairy products with UPLC method. The specific surface area of MIM/g-C(3)N(4) was 172.208 m(2)/g, good thermal stability under 300℃, and could reuse up to 15 times. The four OPPs had good linear relationship within the range of 1–10000 ng/mL (r(2) > 0.999). The limits of detection were 0.7–2.6 ng/mL, and recoveries from blank dairy samples were 86.4 to 95.3 %. In this study, MIM combined with g-C(3)N(4) was firstly utilized for the detection of OPPs in dairy products, which indicated it might be an ideal adsorbent for dairy products pretreatment.