Sulphaquinoxaline [HRP]

In this study, two novel fluorescence quenching immune chromatographic strips (FQICS) were developed to detect sulfaquinoxaline (SQX) in foods of animal origin. These proposed FQICSs were based on fluorescence resonance energy transfer (FRET) from fluorescence donors (quantum dots or upconversion nanoparticles) to fluorescence acceptors (colloidal gold nanoparticles). Compared with traditional colloidal gold-based immune chromatographic strips (ICS), these FQICSs showed positive correlation between the fluorescent signals and the targets, and allowed user to get test results from weak fluorescent signals. The visual detection limits of these two FQICSs were both 1 ng mL(-1) in standard solution and 8 mg kg(-1) in samples, while the visual detection limit of the colloidal gold-based ICS was 10 ng mL(-1) in standard solution and 80 mg kg(-1) in samples. Besides, the results we obtained by the use of FQICS showed high agreement with those obtained by the use of commercial ELISA kits, indicating the good accuracy of these strips. As a conclusion, these proposed FQICS based on quantum dots and upconversion nanoparticles can be applied in sensitive, rapid and on-site detection of SQX in foods of animal origin. (C) 2017 Elsevier B.V. All rights reserved.

A study on the effect of deep-frying at different times and temperatures on sulfonamide (SA) residues in chicken meat-balls has been carried out. The SAs used were sulfadiazine (SDZ), sulfamethazine (SMZ), sulfamethoxazole (SMX), and sulfaquinoxaline (SQX). Time factor (3, 6, and 9 min) showed greater effect on the reduction of SAs compared to the temperature factor (170, 180, and 190 degrees C). Through the Pearson Correlation analysis, reduction of SA concentration was positively related to the increase of the internal temperature during deep-frying process. The weight loss of the chicken meat-balls after deep-frying also is another factor in the reduction of SA residues. The longer the duration of deep-frying and the higher the temperature, the lower SA concentrations were observed. Deep-frying process could help in reducing the SA residues in chicken meat-balls where the maximum reductions obtained were 37.5, 27.5, 40.7, and 27.6% for SDZ, SMZ, SMX, and SQX, respectively at the maximum frying time and temperature. However, controlling the time and temperature of cooking at its best is still needed to retain the taste and appearance of the food. In this study, chicken meat balls fried at 180 degrees C for 6 min resulted in the best condition for outward appearance and consumption as well as reduction in SA residues.