Effects Of Several Natural Water Constitutes On Salbutamol Phototransformation

Pharmaceutical and personal care products(PPCPs)have great impact on our environment due to the environmental behavior,especially the photochemical behavior.Recently,salbutamol has been widely used as medicine which would do harm to human health.However,the photochemical behavior of salbutamol has drawn little attention.Photolysis of PPCPs may be largely influenced by many natural water constitutes,especially carbon-nanotubes,due to their photochemical activities.Our study focused on both the direct photolysis of salbutamol and the effects of several nature water constituents such as NO3-,Fe3+,SRFA and DO as well as three kinds of CNTs(SCNT?MWNT-COOH?MWNT-OH)on the photolysis.In addition,the interaction between CNTs and Fe(?)has been investigated.According to our research,(1)the direct photolysis follows pseudo-first order reaction kinetics while alkaline condition enhances the photodegradation,two possible pathways of SAL direct photolysis were carried out,including oxidation of alcoholic hydroxyl groups and substitution of amino.(2)Nitrate plays such a role as a significant promoter in the photolysis,due to ·OH that generated by nitrate under irradiation.(3)In addition,it is supposed that Fe(III)favors the photolysis process by participating in the chelating reaction with salbutamol.(4)SRFA accelerates the photolysis at higher concentration levels as a photosensitizer while shows an opposite effect at a lower concentration,probably with an energy transfer from SALa*to SRFA.(5)Inhibiting effect has been observed after decreasing the content of dissolved oxygen by means of N2-aeration,suggesting that DO play a positive role in SAL photolysis.(6)The photodegradation of salbutamol followed pseudo-first-order kinetics,which could be inhibited by all three of the CNTs through light screening effect.Singlet oxygen was detected to be formed during the photolysis,using the molecular probe furfuryl alcohol.(7)Fe3+ could adsorb on the surface of CNTs by electrostatic interaction.Consequently,the photochemical activity of Fe3+ has been inhibited.