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Application of time-of-flight mass spectrometry to the analysis of phototransformation products of diclofenac in water under natural sunlight.
J Mass Spectrom. 2005 Jul; 40(7):908-15.JM

Abstract

Exact mass capabilities of time-of-flight (TOF) mass spectrometry along with other mass spectrometric techniques have been evaluated to elucidate a complete range of dichlofenac phototransformation products. Photolysis experiments with diclofenac in water under direct solar irradiation were performed to characterise the main phototransformation products generated and to determine their stability. Photolysis experiments were performed in both demineralised water and reconstructed standard freshwater. Samples were extracted before analysis by solid phase extraction (SPE) with Oasis HLB and MAX cartridges. Separation and identification of the transformation products were accomplished by the combined use of gas chromatography-mass spectrometry (GC/MS) and liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOFMS). Both techniques provided complementary information that enabled the identification of 13 phototransformation products. Six of them were identified by GC/MS through the structural information provided by the full scan mass spectra obtained under electron impact (EI) ionisation and the confirmation of the molecular mass provided by positive chemical ionisation (PCI) analyses. Accurate mass measurements obtained by LC/TOFMS provided the elucidation of seven polar transformation products. The low mass error observed (<2 ppm) enabled the assignment of highly probable empirical formulas as well as identification of a process dimerisation route. The photoproducts identified demonstrated that photolysis of diclofenac occurs by two main routes. One is the consequence of the initial photocyclisation of diclofenac into carbazole derivatives. The other route goes through the initial decarboxilation of diclofenac and further oxidation of the alkyl-chain, which are typical photolytic process reactions. The main photoproduct identified was 8-chloro-9H-carbazole-1yl-acetic acid.

Authors+Show Affiliations

Pesticide Residue Research Group, Faculty of Sciences, University of Almería, 04071-Almería, Spain. aaguera@ual.esNo 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

15934037

Citation

Agüera, A, et al. "Application of Time-of-flight Mass Spectrometry to the Analysis of Phototransformation Products of Diclofenac in Water Under Natural Sunlight." Journal of Mass Spectrometry : JMS, vol. 40, no. 7, 2005, pp. 908-15.
Agüera A, Pérez Estrada LA, Ferrer I, et al. Application of time-of-flight mass spectrometry to the analysis of phototransformation products of diclofenac in water under natural sunlight. J Mass Spectrom. 2005;40(7):908-15.
Agüera, A., Pérez Estrada, L. A., Ferrer, I., Thurman, E. M., Malato, S., & Fernández-Alba, A. R. (2005). Application of time-of-flight mass spectrometry to the analysis of phototransformation products of diclofenac in water under natural sunlight. Journal of Mass Spectrometry : JMS, 40(7), 908-15.
Agüera A, et al. Application of Time-of-flight Mass Spectrometry to the Analysis of Phototransformation Products of Diclofenac in Water Under Natural Sunlight. J Mass Spectrom. 2005;40(7):908-15. PubMed PMID: 15934037.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Application of time-of-flight mass spectrometry to the analysis of phototransformation products of diclofenac in water under natural sunlight. AU - Agüera,A, AU - Pérez Estrada,L A, AU - Ferrer,I, AU - Thurman,E M, AU - Malato,S, AU - Fernández-Alba,A R, PY - 2005/6/4/pubmed PY - 2005/10/14/medline PY - 2005/6/4/entrez SP - 908 EP - 15 JF - Journal of mass spectrometry : JMS JO - J Mass Spectrom VL - 40 IS - 7 N2 - Exact mass capabilities of time-of-flight (TOF) mass spectrometry along with other mass spectrometric techniques have been evaluated to elucidate a complete range of dichlofenac phototransformation products. Photolysis experiments with diclofenac in water under direct solar irradiation were performed to characterise the main phototransformation products generated and to determine their stability. Photolysis experiments were performed in both demineralised water and reconstructed standard freshwater. Samples were extracted before analysis by solid phase extraction (SPE) with Oasis HLB and MAX cartridges. Separation and identification of the transformation products were accomplished by the combined use of gas chromatography-mass spectrometry (GC/MS) and liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOFMS). Both techniques provided complementary information that enabled the identification of 13 phototransformation products. Six of them were identified by GC/MS through the structural information provided by the full scan mass spectra obtained under electron impact (EI) ionisation and the confirmation of the molecular mass provided by positive chemical ionisation (PCI) analyses. Accurate mass measurements obtained by LC/TOFMS provided the elucidation of seven polar transformation products. The low mass error observed (<2 ppm) enabled the assignment of highly probable empirical formulas as well as identification of a process dimerisation route. The photoproducts identified demonstrated that photolysis of diclofenac occurs by two main routes. One is the consequence of the initial photocyclisation of diclofenac into carbazole derivatives. The other route goes through the initial decarboxilation of diclofenac and further oxidation of the alkyl-chain, which are typical photolytic process reactions. The main photoproduct identified was 8-chloro-9H-carbazole-1yl-acetic acid. SN - 1076-5174 UR - https://www.unboundmedicine.com/medline/citation/15934037/Application_of_time_of_flight_mass_spectrometry_to_the_analysis_of_phototransformation_products_of_diclofenac_in_water_under_natural_sunlight_ L2 - https://doi.org/10.1002/jms.867 DB - PRIME DP - Unbound Medicine ER -