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Photolysis and UV/H2O2 of diclofenac, sulfamethoxazole, carbamazepine, and trimethoprim: Identification of their major degradation products by ESI-LC-MS and assessment of the toxicity of reaction mixtures

Journal Article


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Abstract


  • The photolysis of diclofenac (DCF), sulfamethoxazole (SMX), carbamazepine (CBZ), and trimethoprim (TMP) was investigated using a low-pressure (LP) mercury ultraviolet (UV) lamp (254nm) and a combination of UV with hydrogen peroxide (H 2 O 2 ). For each experiment, 5mg/L of each pharmaceutical was prepared in pure water and individually degraded by either UV alone or UV/H 2 O 2 . DCF and SMX were highly susceptible to UV treatment and completely degraded to below their LC-MS detection limit (1μg/L) after only 8min of UV irradiation. TMP and CBZ were more resistant to UV treatment, with only 58.2 and 25.2% degradation (after 1h UV exposure). The combination of H 2 O 2 addition (up to 0.2g/L) with UV significantly improved the removal rate of TMP and CBZ up to 91.2 and 99.7% of the initial concentration, respectively. A number of novel transformation compounds were identified as UV or UV/H 2 O 2 degradation products using LC-MS. The range and amount of these transformation compounds strongly depended on the applied treatment conditions. The toxicity of each pharmaceutical solution before and after treatment was also evaluated and all parent compounds were non-toxic at the tested concentration (i.e. 5mg/L). DCF, in particular, but also CBZ and SMX, showed an increase in solution toxicity after treatment with UV only, indicating the presence of photolytic degradation products that are more toxic than the parent compounds. Treatment with UV/H 2 O 2 reduced the toxicity of all solutions to below the detection limit of the assay.

Authors


  •   Alharbi, Sultan (external author)
  •   Kang, Jinguo (external author)
  •   Nghiem, Long D. (external author)
  •   Van De Merwe, Jason P. (external author)
  •   Leusch, Frederic (external author)
  •   Price, William E.

Publication Date


  • 2017

Citation


  • Alharbi, S. K., Kang, J., Nghiem, L. D., van de Merwe, J. P., Leusch, F. D. L. & Price, W. E. (2017). Photolysis and UV/H2O2 of diclofenac, sulfamethoxazole, carbamazepine, and trimethoprim: Identification of their major degradation products by ESI-LC-MS and assessment of the toxicity of reaction mixtures. Process Safety and Environmental Protection, 112 (Part B), 222-234.

Scopus Eid


  • 2-s2.0-85026512519

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=6151&context=smhpapers

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/5098

Has Global Citation Frequency


Number Of Pages


  • 12

Start Page


  • 222

End Page


  • 234

Volume


  • 112

Issue


  • Part B

Place Of Publication


  • United Kingdom

Abstract


  • The photolysis of diclofenac (DCF), sulfamethoxazole (SMX), carbamazepine (CBZ), and trimethoprim (TMP) was investigated using a low-pressure (LP) mercury ultraviolet (UV) lamp (254nm) and a combination of UV with hydrogen peroxide (H 2 O 2 ). For each experiment, 5mg/L of each pharmaceutical was prepared in pure water and individually degraded by either UV alone or UV/H 2 O 2 . DCF and SMX were highly susceptible to UV treatment and completely degraded to below their LC-MS detection limit (1μg/L) after only 8min of UV irradiation. TMP and CBZ were more resistant to UV treatment, with only 58.2 and 25.2% degradation (after 1h UV exposure). The combination of H 2 O 2 addition (up to 0.2g/L) with UV significantly improved the removal rate of TMP and CBZ up to 91.2 and 99.7% of the initial concentration, respectively. A number of novel transformation compounds were identified as UV or UV/H 2 O 2 degradation products using LC-MS. The range and amount of these transformation compounds strongly depended on the applied treatment conditions. The toxicity of each pharmaceutical solution before and after treatment was also evaluated and all parent compounds were non-toxic at the tested concentration (i.e. 5mg/L). DCF, in particular, but also CBZ and SMX, showed an increase in solution toxicity after treatment with UV only, indicating the presence of photolytic degradation products that are more toxic than the parent compounds. Treatment with UV/H 2 O 2 reduced the toxicity of all solutions to below the detection limit of the assay.

Authors


  •   Alharbi, Sultan (external author)
  •   Kang, Jinguo (external author)
  •   Nghiem, Long D. (external author)
  •   Van De Merwe, Jason P. (external author)
  •   Leusch, Frederic (external author)
  •   Price, William E.

Publication Date


  • 2017

Citation


  • Alharbi, S. K., Kang, J., Nghiem, L. D., van de Merwe, J. P., Leusch, F. D. L. & Price, W. E. (2017). Photolysis and UV/H2O2 of diclofenac, sulfamethoxazole, carbamazepine, and trimethoprim: Identification of their major degradation products by ESI-LC-MS and assessment of the toxicity of reaction mixtures. Process Safety and Environmental Protection, 112 (Part B), 222-234.

Scopus Eid


  • 2-s2.0-85026512519

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=6151&context=smhpapers

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/5098

Has Global Citation Frequency


Number Of Pages


  • 12

Start Page


  • 222

End Page


  • 234

Volume


  • 112

Issue


  • Part B

Place Of Publication


  • United Kingdom