Fate of chlortetracycline in Korean arable soil

The widespread use of the pharmaceutical chlortetracycline to treat human and animal infectious diseases is raising concern in Korea regarding the potential development of antibiotic-resistant bacteria. This study investigated the fate of chlortetracycline in Korean arable soils, to assess its environmental impact. The estimated half-life of chlortetracycline was 26.70-27.17 days indoors and 18.63-30.16 days outdoors. The chlortetracycline epimers and metabolites, 4-epichlortetracycline and 4-epi-anydrochlotetracycline were determined using liquid chromatography tandem mass spectroscopy. The respective concentrations of 4-epi-anydrochlotetracycline and 4-epichlortetracycline were 1.91%-9.71% and 11.12%-23.92% of the total chlortetracycline residual concentration indoors and 2.96%-11.44% and 17.61%-40.73% outdoors.