Development of a time‐resolved fluorescent immunochromatographic test for simultaneous detection of norfloxacin and sulfamethazine in pork samples through green pretreatment

Abstract

AbstractA sensitive time‐resolved fluorescent microsphere immunochromatographic strip test (TRFM‐ICST) was established for the simultaneously rapid detection of norfloxacin (NOR) and sulfamethazine (SM2) in pork samples. Time‐resolved fluorescent europium (III) enclosed polystyrene microspheres conjugated with monoclonal antibody were used as probe to fulfill the analysis. Meanwhile, a green pretreatment system without organic solvent was developed for pork samples. Pork samples were processed by extracting buffer [citric acid buffer (0.01 M, pH 4.4) containing 2% (vol/vol) of Tween‐20 and 2% (wt/vol) of polyvinyl pyrrolidone (mass weight = 10,000)] and diluting buffer [phosphate buffered solution (0.01 M, pH 7.2) containing 1% (wt/vol) of Tween‐20 and 1% (wt/vol) of polyethylene glycol (mass weight = 400)]. The working range of TRFM‐ICST for NOR and SM2 in pork samples was 2.74–18.70 and 0.49–3.02 μg kg−1, respectively. Negative pork samples spiked with NOR and SM2 were detected by established TRFM‐ICST and high‐performance liquid chromatography (HPLC). The linear regression analysis yielded a good correlation between TRFM‐ICST and HPLC (Y = 0.9309X + 0.039, R2 = .9965, relative standard deviation (RSD) = 1.95%). The recovery of NOR and SM2 in pork samples was 94.1–114.4 and 93.0–102.0%, respectively, illustrating the proposed TRFM‐ICST can be applied for screening of high throughput pork samples.