Matrix effect of five kinds of meat on colloidal gold immunochromatographic assay for sulfamethazine detection

Abstract

A colloidal gold immunochromatographic assay (CG-ICA) was developed to detect sulfamethazine (SM₂) residues in five kinds of meat: namely, chicken, pork, shrimp, beef, and fish. The limit of detection (LOD) of CG-ICA for SM₂ detection was 0.104 ng mL⁻¹ within 20 min. CG-ICA exhibited a wide linear range of 0.1 ng mL⁻¹ to 96 ng mL⁻¹ with a reliable correlation coefficient (R² = 0.9938). The average recoveries of CG-ICA for SM₂ detection in chicken, pork, shrimp, beef, and fish were 98.1% ± 4.6%, 86.1% ± 0.5%, 86.2% ± 4.9%, 71.7% ± 1.7%, and 79.2% ± 2.5%, respectively. The matrix effect of the five kinds of meat on CG-ICA was also assessed. The standard curves of the five matrices did not coincide with the standard curve of phosphate buffer saline, indicating that a matrix effect had occurred in CG-ICA for SM₂ detection in the five matrices. The strongest matrix effect was elicited by beef, followed by fish, pork, and shrimp, whereas the weakest matrix effect was produced by chicken.