The fate of prazosin and levonorgestrel after electrochemical degradation process: Monitoring by-products using LC-TOF/MS
Fouad FadhilAl-Qaim , Zainab Haider Mussa , Ali Yuzir , Jalifah Latip , Mohamed Rozali Othman
DOI:10.1016/j.jes.2018.02.019
Received January 01, 1900,Revised January 01, 1900, Accepted January 01, 1900, Available online January 01, 1900
Volume 30,2018,Pages 134-146
Prazosin (PRZ) and levonorgestrel (LNG) are widely used as an anti-disease drugs due to their biological activity in the human body. The frequent detection of these compounds in water samples requires alternative technologies for the removal of both compounds. After electrochemical degradation of PRZ and LNG, the parent compounds could be completely removed after treatment, but the identification and characterization of by-products are necessary as well. In this study, the effects of NaCl concentration and applied voltage were investigated during the electrochemical degradation process. The results revealed that the increase of NaCl concentration and applied voltage could promote the generation of hypochlorite OCl− and then enhance the degradation of PRZ and LNG. After initial study, 6 V and 0.2 g NaCl were selected for further experiments (96% and 99% removal of PRZ and LNG after 40 min, respectively). Energy consumption was also evaluated and calculated for PRZ and LNG at 3, 6 and 8 V. Solid phase extraction (SPE) method plays an important role in enhancing the detection limit of by-products. Furthermore, characterization and identification of chlorinated and non-chlorinated by-products were conducted using an accurate liquid chromatography-time of flight/mass spectrometry LC-TOF/MS instrument. The monitoring of products during the electrochemical degradation process was performed at 6 V and 0.2 g NaCl in a 50 mL solution. The results indicated that two chlorinated products were formed during the electrochemical process. The toxicity of by-products toward E. coli bacteria was investigated at 37°C and 20 hr incubation time.
