TY - JOUR
T1 - Photocatalytic transformation of acesulfame
T2 - Transformation products identification and embryotoxicity study
AU - Li, Adela Jing
AU - Schmitz, Oliver J.
AU - Stephan, Susanne
AU - Lenzen, Claudia
AU - YUE, Patrick Y K
AU - Li, Kaibin
AU - Li, Huashou
AU - LEUNG, Kelvin S Y
N1 - Funding Information:
We thank the Hong Kong Research Grants Council (HKBU 201113) for the financial support. Kelvin S.–Y. Leung also thanks the grants from the Partner State Key Laboratory of Environmental and Biological Analysis (SKLP-14-15-P006) and Faculty of Science (FRG/12–13/067 and FRG/13–14/069), Hong Kong Baptist University.
PY - 2016/2/1
Y1 - 2016/2/1
N2 - Artificial sweeteners have been recognized as emerging contaminants due to their wide application, environmental persistence and ubiquitous occurrence. Among them, acesulfame has attracted much attention. After being discharged into the environment, acesulfame undergoes photolysis naturally. However, acesulfame photodegradation behavior and identity of its transformation products, critical to understanding acesulfame's environmental impact, have not been thoroughly investigated. The present study aimed to fill this knowledge gap by a laboratory simulation study in examining acesulfame transformation products and pathways under UV-C photolysis in the presence of TiO2. Photodegradation products of acesulfame were isolated and analyzed using the LC-IM-QTOF-MS coupled with LC Ion Trap MS in the MSn mode. Our results show six new transformation products that have not been previously identified. The molecular structures and transformation pathways were proposed. Further embryotoxicity tests showed that acesulfame transformation products at the low g L-1 level produced significant adverse effects in tail detachment, heart rate, hatching rate and survival rate during fish embryo development. The identification of additional transformation products with proposed transformation pathways of acesulfame, the increased toxicity of acesulfame after photolysis, and the fact that the accumulation of acesulfame transformation products is increasingly likely make acesulfame contamination even more important. Water resource control agencies need to consider legislation regarding acesulfame and other artificial sweeteners, while further studies are carried out, in order to protect the safety of this most vital resource.
AB - Artificial sweeteners have been recognized as emerging contaminants due to their wide application, environmental persistence and ubiquitous occurrence. Among them, acesulfame has attracted much attention. After being discharged into the environment, acesulfame undergoes photolysis naturally. However, acesulfame photodegradation behavior and identity of its transformation products, critical to understanding acesulfame's environmental impact, have not been thoroughly investigated. The present study aimed to fill this knowledge gap by a laboratory simulation study in examining acesulfame transformation products and pathways under UV-C photolysis in the presence of TiO2. Photodegradation products of acesulfame were isolated and analyzed using the LC-IM-QTOF-MS coupled with LC Ion Trap MS in the MSn mode. Our results show six new transformation products that have not been previously identified. The molecular structures and transformation pathways were proposed. Further embryotoxicity tests showed that acesulfame transformation products at the low g L-1 level produced significant adverse effects in tail detachment, heart rate, hatching rate and survival rate during fish embryo development. The identification of additional transformation products with proposed transformation pathways of acesulfame, the increased toxicity of acesulfame after photolysis, and the fact that the accumulation of acesulfame transformation products is increasingly likely make acesulfame contamination even more important. Water resource control agencies need to consider legislation regarding acesulfame and other artificial sweeteners, while further studies are carried out, in order to protect the safety of this most vital resource.
KW - Acesulfame
KW - Catalytic UV irradiation
KW - Embryotoxicity
KW - Emerging contaminant
KW - Transformation pathway
KW - Transformation product
UR - http://www.scopus.com/inward/record.url?scp=84962630902&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2015.11.035
DO - 10.1016/j.watres.2015.11.035
M3 - Journal article
C2 - 26630044
AN - SCOPUS:84962630902
SN - 0043-1354
VL - 89
SP - 68
EP - 75
JO - Water Research
JF - Water Research
ER -