Development of a multicomponent immunochromatographic test system for the detection of fluoroquinolone and amphenicol antibiotics in dairy products.

BACKGROUND: Ciprofloxacin (CIP) and chloramphenicol (CAP) are relevant antibiotics of the fluoroquinolone (FQ) and amphenicol (AP) groups, respectively, widely used in veterinary practice and they contaminate agricultural products. In this study, a rapid and sensitive immunochromatographic assay (ICA) was developed for simultaneous detection of CIP and CAP in dairy products. The ICA was carried out in a direct competitive format using gold nanoparticles as a label. RESULTS: The ICA developed here allowed for the detection of CIP and CAP in Triton X-100-containing buffered saline (PBST) within 15 min with instrumental detection limits of 20 pg mL-1 and 0.5 ng mL-1 , respectively, and with a visual detection limit of 5 ng mL-1 for both antibiotics. The ICA showed cross-reactivity (69-160%) to 19 antibiotics in the FQ group and no cross-reactivity (<0.1%) to 2 antibiotics of the AP group. The ICA allowed detection of CIP and CAP in a panel of dairy products by employing a simple procedure of preliminary sample preparation. The detection limits for the two antibiotics were the same as in PBST. The analytical recoveries of CIP and CAP in dairy products ranged from 83% to 120%. CONCLUSION: The analytical characteristics of the test system allow its use for the detection of antibiotics in milk and dairy products during all steps of production. © 2019 Society of Chemical Industry.

[The detection of amphetamines in urine samples using immunochromatographic test strips].

This study has demonstrated the possibility of using immunochromatographic test strips for the reliable qualitative detection of amphetamine and methamphetamine in the urine samples at a cut-off level of 300 ng/ml. The test strips obtained from different manufactures are shown to be slightly different in terms of specificity as appears from the frequency of cross-reactions with various pharmaceutical products and narcotic drugs. Also, the use of the immunochromatographic strips makes it possible to determine amphetamine in a range of concentrations from 100 to 1000 ng/ml by measuring the intensity of test-line colour with the help of a TotalLab TL120 programmer and special scanning programs. The analysis for amphetamine using the NrcoStop (Osiris S) immunochromatographic strips failed to confirm the presence of this substance in the urine samples from the subjects who had drunk 0.5 l of energy drinks, such as Adrenaline RUSH, Red Bull, and Burn. It means that the presence of amphetamine in the urine should not be attributed to the consumption of such drinks.