Document Detail

Photochemical behaviour of musk tibetene. A chemical and kinetic investigation.
MedLine Citation:
PMID:  18504835     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Synthetic musk compounds are widely used as additives in personal care and household products. The photochemical degradation of musk tibetene in aqueous solutions or in acetonitrile/water mixtures under different conditions was studied in order to assess its environmental fate. METHODS: Musk tibetene dissolved (or suspended) in water and/or acetonitrile/water mixtures was irradiated at different times by UV-light and by solar light. The irradiation mixtures were analyzed by NMR and TLC. The photoproducts formed were identified by GC-MS and NMR data. RESULTS: The experimental results indicated that musk tibetene was photodegradable in water or acetonitrile/water mixtures with half-life reaction times close to 20 minutes. The irradiation mixtures were separated by chromatographic techniques yielding three photoproducts (3,3,5,6,7-pentamethyl-4-nitro-3H-indole, 3,3,5,6,7-pentamethyl-4-nitro-1H-indoline and 3,3,5,6,7-pentamethyl-4-nitro-3H-indolinone) identified by means of spectroscopic analysis. DISCUSSION: The numerical modelling of the photodegradation concentration-time profiles gave (8.13 +/- 0.15) x 10(-2) and (1.34 +/- 0.04) x 10(-2) mol/E for the overall primary quantum yield of direct photolysis for musk tibetene and the major intermediate (3,3,5,6,7-pentamethyl-4-nitro-3H-indolinone), respectively, in the wavelength range 305-366 nm. The half-life times of photodegradation of the both substances varied from 1-1.5 hours at 20 degrees N during the summer season to 6-10 hours for highest latitudes in winter. CONCLUSIONS: Under solar light, musk tibetene was photolabile in acetonitrile and acetonitrile/water 1/1, while it was slowly degraded when suspended in water. In all media, musk tibetene was photodegraded into three photoproducts. By using a kinetic model, the overall primary quantum yields of direct photolysis of musk tibetene and its main photoproduct, in the wavelength range 305-366 nm, were estimated, indicating that the photodegradation rate for musk tibetene is faster than the photolysis rate of the major by-product. RECOMMENDATIONS AND PERSPECTIVES: The results indicate that, in order to assess the environmental impact of musk tibetene on the aquatic ecosystem, great attention should be focused on the major photoproduct which is proved to be more persistent than the parent compound under light irradiation. The predicted half-life times of direct photolysis for both substances ranged from 1-1.5 hours at 20 degrees N during the summer season to about 6-10 hours for highest latitudes in winter, indicating that, from a photochemical point of view, the environmental persistence of these substances increases by increasing the latitudes and during the cold seasons, making more realistic an intake of these xenobiotic molecules into the food chain of aquatic living organisms. Tanabe reports in his Editorial (Tanabe 2005) that "It is necessary to have knowledge of the global picture of synthetic musk pathways. So, it is conceivable that now is the time to study the transport, persistency, distribution, bioaccumulation and toxic potential of this new environmental menace on a global scale, especially in developing countries". Therefore, the future environmental analysis and investigations on the eco-toxicity of nitro musk compounds should take into account not only the presence of the parent compounds but also their photochemical intermediates or end-by-products.
Marisa Canterino; Raffaele Marotta; Fabio Temussi; Armando Zarrelli
Related Documents :
8386045 - Identification of irradiated foodstuffs: results of a european test intercomparison.
12903955 - Influences of gamma-irradiation and storage on the carotenoids of sun-dried and dehydra...
2230505 - Morphological variations of the ulnar styloid process.
17674845 - Ultrasound as a pre-oxidation for biological landfill leachate treatment.
23287585 - Timing of introduction of solid food and risk of allergic disease development: understa...
1619105 - Differential development and reproduction of the german cockroach (dictyoptera: blattel...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Environmental science and pollution research international     Volume:  15     ISSN:  0944-1344     ISO Abbreviation:  Environ Sci Pollut Res Int     Publication Date:  2008 May 
Date Detail:
Created Date:  2008-05-26     Completed Date:  2008-06-10     Revised Date:  2009-08-14    
Medline Journal Info:
Nlm Unique ID:  9441769     Medline TA:  Environ Sci Pollut Res Int     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  182-7     Citation Subset:  IM    
Università di Napoli Federico II, Facoltà di Ingegneria, Dipartimento di Ingegneria Chimica, P.le V. Tecchio, 80-80125 Napoli, Italy.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Acetonitriles / chemistry
Dinitrobenzenes / chemistry,  radiation effects*
Humic Substances
Nitrates / chemistry
Potassium Compounds / chemistry
Ultraviolet Rays*
Water Pollutants, Chemical / chemistry,  radiation effects*
Reg. No./Substance:
0/Acetonitriles; 0/Dinitrobenzenes; 0/Humic Substances; 0/Nitrates; 0/Perfume; 0/Potassium Compounds; 0/Water Pollutants, Chemical; 145-39-1/musk tibetine; 75-05-8/acetonitrile; 7757-79-1/potassium nitrate

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Modeling the spill in the Songhua River after the explosion in the petrochemical plant in Jilin.
Next Document:  Biodegradation of phenolic mixtures in a sequencing batch reactor. A kinetic study.