title: Aquatic photolysis of β2-agonist salbutamol: kinetics and mechanism studies.
abstract: Salbutamol (SAL) has been widely used as medicine both in treating asthma and in animal primary production; an increasing number of reports have detected SAL in natural waters. The photolysis kinetic and pathway of SAL in aquatic system were studied, as well as the effect of several natural water constituents, such as nitrate, dissolved oxygen (DO) and ferric ions. According to our research, the direct photolysis of SAL followed pseudo-first-order reaction kinetics. Alkaline condition could promote the degradation of SAL; the increase of solution pH would simultaneously increase the fraction of the deprotonated forms of SAL (including the deprotonated and zwitterionic species), which were easier to be excited, and result in the bathochromic shift of the UV-Vis spectrum and, finally, accelerate the degradation rate of SAL. The presence of nitrate could enhance the removal rate of SAL via generation hydroxyl radical (·OH) under irradiation. In addition, the absence of oxygen in the reaction solution could decrease the photolysis. Moreover, Fe(III) was able to chelate with SAL to form an octahedral complex, which was photochemically reactive. The octahedral complex could generate ·OH to oxidize SAL itself in turn. The pathways of SAL photolysis were also investigated by means of the solid phase extraction (SPE)-LC-MS method. The major pathways of SAL photodegradation included oxidation and side-chain cleavage.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China. lei.zhou@ircelyon.univ-lyon1.fr.|Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, 69626, Villeurbanne, France. lei.zhou@ircelyon.univ-lyon1.fr.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Nanjing, 210042, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Yuefei
authors.initials: Y
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China. yangxi@nju.edu.cn.
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
mesh_terms: D000420:Albuterol; D005290:Ferric Compounds; D017665:Hydroxyl Radical; D007501:Iron; D007700:Kinetics; D009566:Nitrates; D010100:Oxygen; D010782:Photolysis; D012996:Solutions; D014867:Water; D014874:Water Pollutants, Chemical
chemical_list: D005290:Ferric Compounds; D009566:Nitrates; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; D017665:Hydroxyl Radical; D007501:Iron; D000420:Albuterol; D010100:Oxygen
keywords: Dissolved oxygen; Iron ion; Nitrate; Photolysis; Salbutamol