Determination of Trace Oxytetracycline in Wasterwater by Phase-Separation Floatation with Ultraviolet Detection

In the present work, a novel analytical method was proposed for the determination of trace oxytetracycline(OTC) in wastewater by phase-separation floatation(PSF) coupled with an ultraviolet detector setting at 375 nm. OTC can be transformed into tenary complex(Co-OTC-DNA) in the presence of cobalt(II) and deoxyribonucleic acid (DNA) which can be separated by phase-separation floatation easily. The optimum phase-separation floatation was performed on phase-separation reagent using 1 mol·L^-1 sodium chloride, caustic soda solution as acidity regulator and tetrahydrofuran(THF) as solvent. The linear regression equation is A=7.85×10⁵C-0.002, linear range is from 5.0×10^-8-1.0×10^-5 mol·L^-1, lower limit of detection (LOD) was 3.82×10^-9 mol·L^-1. The recoveries of OTC in water samples were 99.1-99.4%.