Chromatographic quantification of drug residues in food of animal origin RS-502 (RSPAC 2-6)

Abstract

Nowadays, livestock marketed products represent forty percent of the daily diet. Meanwhile, veterinary drugs are also widely used for diverse intentions, including maintaining health and improving feed efficiency of animals. However, the most used class of veterinary drugs is antibiotics including Trimethoprim (TMP) and Sulfadiazine (SDZ). The overdosing or the sudden stop of these agents causes the accumulation of drug residue in different animal. Subsequently, consumption of livestock products containing such residues may impose negative effects on human health. Consequently, the present work is devoted to the development of sensitive HPLC-UV methods for the quantitative estimation of TMP and SDZ in chicken muscles. In method 1; the drugs were extracted using methanol. Chromatographic separation was accomplished on a C18 column and mobile phase of water: ethanol (90: 10 v/v) pH = 5.5 using 0.1N acetic acid. The UV detection was at 230 nm and 280 nm for TMP and SDZ, respectively. The method was linear in the range of 0.5-50 μg/mL and 0.5-60 μg/mL for TMP and SDZ, respectively. In method 2 (Micellar Chromatography); 0.1 M SDS was used to extract the two drugs. Chromatographic separation was performed on Xterra C18 column and mobile phase composed of 0.1M SDS: acetonitrile (90: 10 v/v) pH = 5.5 with 0.1 N citric acid. The UV detection was 254 nm. The developed method was linear in the range of 0.5-100 μg/mL for both drugs. The obtained recoveries in the spiked chicken samples were found satisfactory. The developed HPLC-UV methods were validated in accordance to the ICH guidelines proving the methods to be accurate, precise and selective.