Antibiotic Determination In Water Environment And Distribution In The Coastal Zone Of China By The Discharge Of Land-based Wastewater

Antibiotics are not only administered worldwide in human and animal medicine for the treatment of infections but are an integral part of modern animal production. After consumption, a great part of antibiotic pharmaceuticals mainly enter the environment unmetabolited and can eventually reach the aquatic environment. Their environmental occurrence and fate is of particular interest, due to the potential spread and maintenance of antibacterial resistance. The research focuses on the sulfonamides and chloramphenicol, which are used frequently as human and animal medicines.This research developed a rapid method for the determination of 14 kinds of sulfonamides (SAs) in wastewater using solid-phase extraction (SPE), and liquid chromatography tandem mass spectrometry (LC-MS/MS) with positive electrospray ionization (ESI(+)) and multiple reaction monitoring (MRM) mode. The SPE was performed on an Oasis HLB cartridge. Chromatographic separation on a C18 column was achieved using a binary eluent containing methanol and water with 0.2% formic acid. Typical recoveries of the analytes ranged from 22.3% to 87.0% at a fortification level of 100 ng/L. The limits of detection (LOD) in wastewater except sulfathiazole (3 ng/L) could be detected and quantified at levels as low as 1 ng/L.Chloramphenicol in water was extracted liquid-liquid extraction and determined by HPLC-MS/MS, using methanol-water (80:20) as the mobile phase. The spectral acquisition was done in the negative electron spray ionization utilizing multiple reaction monitoring of three parent- daughter ion pairs: m/z 321/121, 321/152 and 321/176. The ion pair of m/z 321/152 was used for quantitation. Linear plots were obtained between 0.1μg/L and 100μg/L, with linear correlation coefficient of 0.9993. The limit of detection was 10 ng/L. Ultrasonic assistance extraction followed by HPLC analysis was applied for the determination of the concentration in the sediment samples. In 2006, an antibiotic monitoring campaign was carried out, which focused on the distribution in the coastal zone of China by the discharge of land-based wastewater. The result shows the water occurred the sulfonamide antibiotics' residue. But they are lower than the water pollution level in the developed countries. However, with its large-scale production and application, the problem of pollution is becoming more and more serious. The municipal wastewater discharge is the most important source of sulfonamides in these sites. All 54 water samples have not been detected chloramphenicol residues. For the investigation in aquaculture environment, water samples were found chloramphenicol residues.