Development of a broad-specific immunochromatographic assay for the screening of diclofenac and its analogs in health tea and health beverages

Diclofenac (DIC) is often mixed into health products by unscrupulous merchants to claim antirheumatic effects. In this study, A highly sensitive group-selective monoclonal antibody (mAb) was prepared, and an immunochromatographic assay was developed for rapid screening of DIC, diclofenac methyl (DICA) and N-phenylanthranilic acid (PAA) in health teas and health beverages. In our quantitative analysis, the LOQs for the immunochromatographic test strip (ICS) for the detection of DIC (DICA and PAA) in health tea and health beverage were 0.17 (1.13 and 1.34) and 0.12 (0.25 and 0.53) ng/mL, respectively. This method was compared with LC-MS/MS method to detect the spiked samples, and the results were in good agreement with the LC-MS/MS, to verifying the effectiveness of the new method. Therefore, the ICS we have developed appears to be suitable for monitoring in-field residue levels of DIC, DICA and PAA in real samples.