Photochemical characteristics of diclofenac and its photodegradation of inclusion complexes with β-cyclodextrins

Abstract

Recebido em 3/7/11; aceito em 29/9/11; publicado na web em 6/12/11 Diclofenac is one of most frequently detected compounds in the water cycle. In this work, the effect of initial concentration, liquid inclusion complexes with β-Cyclodextrins (β-CDs) on the photodegradation of diclofenac were studied. Six phototransformation products were detected by HPLC chromatograms. UV-absorption spectra of diclofenac and phototransformation products were determined. One of the phototransformation products was identified. The degradation followed pseudo-first-order kinetics. The experiment showed that irradiation of diclofenac in the presence of β-CDs increase photodegradation rate and determined the optimal molar ratio of diclofenac to β-CDs as 1:2. The reduced photohaemolytic activity of diclofenac in the presence of β-CDs may be attributed to the sequestering and stabilizing of the radical intermediates and /or photoproducts by complexation.

TiO2-assisted photocatalytic degradation of diclofenac, metoprolol, estrone and chloramphenicol as endocrine disruptors in water

“…That was in agreement with the results obtained by Zhang et al (2011), Martínez et al (2011) or Qin et al (2012). (8-chloro-9H-carbazol-1-yl)acetic acid may be obtained as the result of *OH addition to 2-(8-chloro-9H-carbazol-1-yl)acetic acid, the product of photocyclization to the monohalogenated carbazole, involving loss of chlorine and hydrogen atoms, followed by structural rearrangement resulting in the formation of a new ring.…”

“…PPCPs in the environment are derived from usage by individuals and pets (in the households and intensive animal breeding farms as growth enhancers), disposal of outdated medications in sewage systems, release of treated and untreated hospital and veterinary wastes to domestic sewage systems, transfer of sewage solids (biosolids) to land, industrial waste streams and releases from aquaculture of medicated feeds, etc. (Ellis 2006;Fatta-Kassinos et al 2011;Qin et al 2012). A total of 170 pharmaceutical chemicals are estimated to be used in excess of 1 tone per year (Ellis 2006).…”

Diclofenac and its transformation products: Environmental occurrence and toxicity - A review

“…The half-life of DCF is estimated to be 3.3 h (Schmitt-Jansen et al, 2007). DCF followed first order kinetics during photodegradation and was detected in water cycle (Qin and Yang, 2012). Photodegradation was identified as the main removal process for the degradation of DCF in lakes and it was estimated that about 90% of DCF was eliminated by this process (Buser et al, 1998).…”

“…Photodegradation was identified as the main removal process for the degradation of DCF in lakes and it was estimated that about 90% of DCF was eliminated by this process (Buser et al, 1998). Many phototransformation products of DCF were identified by various researchers (Agüera et al, 2005;Moore et al, 1990;Qin and Yang, 2012). Most significant process of DCF phototransformation was identified as the photocyclisation to the corresponding monohalogenated carbazole (Eriksson et al, 2010).…”

A Review of Pharmaceuticals and Endocrine-Disrupting Compounds: Sources, Effects, Removal, and Detections

“…In the same vein, PPCPs and EDCs come into the aquatic environment through the discharge of residual chemicals by householders and by agronomy and manufacturing industries ( Fig. 1) (Boyd et al 2003;Bonefeld-Jorgensen et al 2007;Besse et al 2008;Besse and Garric 2009;Sellin et al 2009;Kümmerer and Al-Ahmad 2010;Vulliet and Cren-Olivé 2011;Brausch and Rand 2011;Besse et al 2012;Qin et al 2012). Houeto et al (2012) affirmed the presence of metabolized and partially metabolized drug residues in various water sources such as wastewater, groundwater, surface water, and drinking water.…”