Tags

Type your tag names separated by a space and hit enter

Lorazepam photofate under photolysis and TiO2-assisted photocatalysis: identification and evolution profiles of by-products formed during phototreatment of a WWTP effluent.
Water Res. 2013 Oct 01; 47(15):5584-93.WR

Abstract

This manuscript reports on the study of Lorazepam (LZP) phototransformation pathways under artificial UV and natural solar irradiation, through photolytic and TiO2-assisted photocatalytic processes. Three experimental set-ups were employed: two lab-scale photoreactors, each provided with an UV lamp (one medium pressure mercury lamp and one blacklight blue lamp), and a pilot-scale Solar Plant with Compound Parabolic Collectors (CPCs). Samples collected along the different phototreatment experiments were analyzed by ultra-high performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UHPLC/QqToF-MS). The key assumption of the analytical approach was that related compounds (LZP and its by-products (LBPs)) provide identical "diagnostic fragment ions". Identification was also based on the chlorine atoms specific isotopic pattern, as well as accurate masses. Six major LBPs were identified and elucidated, with nominal [M + H](+) masses of 337, 303, 319, 275, 291 and 293 Da. The proposed LZP photodegradation mechanism included the initial opening of the diazepinone seven-membered ring, followed by a rearrangement into a highly stabilized six-membered aromatic ring and subsequent cleavage and/or hydroxylation reactions. The evolution profiles of LBPs were described for each of the three experimental prototypes and the CPCs Solar Pilot Plant proved to be the most efficient one. Finally, LZP photocatalytic degradation was further assessed on a municipal effluent, where the photoproducts generated showed to be more persistent than LZP itself.

Authors+Show Affiliations

Department of Bromatology and Hydrology, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; IAREN - Water Institute of the Northern Region, Rua Dr. Eduardo Torres 229, 4450-113 Matosinhos, Portugal.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

23998389

Citation

Sousa, M A., et al. "Lorazepam Photofate Under Photolysis and TiO2-assisted Photocatalysis: Identification and Evolution Profiles of By-products Formed During Phototreatment of a WWTP Effluent." Water Research, vol. 47, no. 15, 2013, pp. 5584-93.
Sousa MA, Lacina O, Hrádková P, et al. Lorazepam photofate under photolysis and TiO2-assisted photocatalysis: identification and evolution profiles of by-products formed during phototreatment of a WWTP effluent. Water Res. 2013;47(15):5584-93.
Sousa, M. A., Lacina, O., Hrádková, P., Pulkrabová, J., Vilar, V. J., Gonçalves, C., Boaventura, R. A., Hajšlová, J., & Alpendurada, M. F. (2013). Lorazepam photofate under photolysis and TiO2-assisted photocatalysis: identification and evolution profiles of by-products formed during phototreatment of a WWTP effluent. Water Research, 47(15), 5584-93. https://doi.org/10.1016/j.watres.2013.06.029
Sousa MA, et al. Lorazepam Photofate Under Photolysis and TiO2-assisted Photocatalysis: Identification and Evolution Profiles of By-products Formed During Phototreatment of a WWTP Effluent. Water Res. 2013 Oct 1;47(15):5584-93. PubMed PMID: 23998389.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Lorazepam photofate under photolysis and TiO2-assisted photocatalysis: identification and evolution profiles of by-products formed during phototreatment of a WWTP effluent. AU - Sousa,M A, AU - Lacina,O, AU - Hrádková,P, AU - Pulkrabová,J, AU - Vilar,Vítor J P, AU - Gonçalves,C, AU - Boaventura,Rui A R, AU - Hajšlová,J, AU - Alpendurada,M F, Y1 - 2013/06/26/ PY - 2013/03/04/received PY - 2013/06/13/revised PY - 2013/06/17/accepted PY - 2013/9/4/entrez PY - 2013/9/4/pubmed PY - 2014/4/12/medline KW - By-products KW - CPCs solar pilot plant KW - Lorazepam KW - TiO(2)-photocatalysis KW - Ultra-high performance liquid chromatography–high resolution mass spectrometry SP - 5584 EP - 93 JF - Water research JO - Water Res VL - 47 IS - 15 N2 - This manuscript reports on the study of Lorazepam (LZP) phototransformation pathways under artificial UV and natural solar irradiation, through photolytic and TiO2-assisted photocatalytic processes. Three experimental set-ups were employed: two lab-scale photoreactors, each provided with an UV lamp (one medium pressure mercury lamp and one blacklight blue lamp), and a pilot-scale Solar Plant with Compound Parabolic Collectors (CPCs). Samples collected along the different phototreatment experiments were analyzed by ultra-high performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UHPLC/QqToF-MS). The key assumption of the analytical approach was that related compounds (LZP and its by-products (LBPs)) provide identical "diagnostic fragment ions". Identification was also based on the chlorine atoms specific isotopic pattern, as well as accurate masses. Six major LBPs were identified and elucidated, with nominal [M + H](+) masses of 337, 303, 319, 275, 291 and 293 Da. The proposed LZP photodegradation mechanism included the initial opening of the diazepinone seven-membered ring, followed by a rearrangement into a highly stabilized six-membered aromatic ring and subsequent cleavage and/or hydroxylation reactions. The evolution profiles of LBPs were described for each of the three experimental prototypes and the CPCs Solar Pilot Plant proved to be the most efficient one. Finally, LZP photocatalytic degradation was further assessed on a municipal effluent, where the photoproducts generated showed to be more persistent than LZP itself. SN - 1879-2448 UR - https://www.unboundmedicine.com/medline/citation/23998389/Lorazepam_photofate_under_photolysis_and_TiO2_assisted_photocatalysis:_identification_and_evolution_profiles_of_by_products_formed_during_phototreatment_of_a_WWTP_effluent_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0043-1354(13)00520-4 DB - PRIME DP - Unbound Medicine ER -