TY - JOUR
T1 - Environmental behavior of 12 UV filters and photocatalytic profile of ethyl-4-aminobenzoate
AU - Li, Adela Jing
AU - Sang, Ziye
AU - Chow, Chi Hang
AU - Law, Japhet Cheuk Fung
AU - Guo, Ying
AU - Leung, Kelvin S Y
N1 - Funding Information:
We thank the Science, Technology and Innovation Commission of Shenzhen (JCYJ20150630164505506) for the financial support. Kelvin S.?Y. Leung also thanks the grants from the inter-institutional Collaborative Research Scheme (RC-ICRS/14-15/02) and Faculty of Science (FRG2/15-16/069), Partner State Key Laboratory of Environmental and Biological Analysis (SKLP_1617_P03), Hong Kong Baptist University. Z. ?Y. Sang, J.C.-F. Law and C.-H. Chow gratefully acknowledge their receipt of postgraduate studentships from the University Grants Committee.
PY - 2017/9/5
Y1 - 2017/9/5
N2 - Ethyl-4-aminobenzoate (Et-PABA) is currently used as a substitute for 4-aminobenzoate (PABA) in sunscreens and anesthetic ointments. Despite its widespread use and hydrophilicity, Et-PABA has never been found in environmental waters. This study, probed the occurrence of Et-PABA in both seawater and drinking water sources in Hong Kong, and evaluated its transformation products (TPs) and environmental fate via cumulative potency and photocatalytic profile analyses. Another 11 UV filters used in skin-care products were also studied. Et-PABA was not detected in any water sample. Four other UV filters were dominant at ng/L level in both seawater and drinking water sources. UHPLC-QTOF-MS was used to elucidate the structure of TPs. With high resolution accurate mass data and fragment rationalization, 11 Et-PABA TPs were characterized, including seven intermediates firstly proposed as TPs; two compounds were reported for the first time. It is proposed that photocatalysis induces transformation pathways of (de)hydroxylation, demethylation and molecular rearrangement. Luminescent bacteria tests showed decreasing toxicity with increasing irradiation of Et-PABA, suggesting that irradiation TPs are less toxic than the parent compound. Transformation of Et-PABA appears to explain why Et-PABA has not been detected in the natural environment.
AB - Ethyl-4-aminobenzoate (Et-PABA) is currently used as a substitute for 4-aminobenzoate (PABA) in sunscreens and anesthetic ointments. Despite its widespread use and hydrophilicity, Et-PABA has never been found in environmental waters. This study, probed the occurrence of Et-PABA in both seawater and drinking water sources in Hong Kong, and evaluated its transformation products (TPs) and environmental fate via cumulative potency and photocatalytic profile analyses. Another 11 UV filters used in skin-care products were also studied. Et-PABA was not detected in any water sample. Four other UV filters were dominant at ng/L level in both seawater and drinking water sources. UHPLC-QTOF-MS was used to elucidate the structure of TPs. With high resolution accurate mass data and fragment rationalization, 11 Et-PABA TPs were characterized, including seven intermediates firstly proposed as TPs; two compounds were reported for the first time. It is proposed that photocatalysis induces transformation pathways of (de)hydroxylation, demethylation and molecular rearrangement. Luminescent bacteria tests showed decreasing toxicity with increasing irradiation of Et-PABA, suggesting that irradiation TPs are less toxic than the parent compound. Transformation of Et-PABA appears to explain why Et-PABA has not been detected in the natural environment.
KW - Environmental occurrence
KW - Ethyl-4-aminobenzoate
KW - Photocatalysis
KW - Transformation products
KW - Triolein-SPMD
UR - http://www.scopus.com/inward/record.url?scp=85019119476&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2017.04.067
DO - 10.1016/j.jhazmat.2017.04.067
M3 - Journal article
C2 - 28511043
AN - SCOPUS:85019119476
SN - 0304-3894
VL - 337
SP - 115
EP - 125
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
ER -
