Development and evaluation of sunlight actinometers

Dulin, David; Mill, Theodore

doi:10.1021/es00105a017

Cited by 313 publications

(259 citation statements)

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“…1, the emission spectrum of the lamp recorded using fiber optics coupled with a charge-coupled device (CCD) spectrophotometer (Ocean Optics USD 2000+UV-VIS) is reported. The energy was normalized with the actinometry results using a paranitroanisole (PNA)/pyridine actinometer (Dulin and Mill, 1982). Over the wavelength range of 290- …”

Section: Irradiation Experimentsmentioning

confidence: 99%

A better understanding of hydroxyl radical photochemical sources in cloud waters collected at the puy de Dôme station – experimental versus modelled formation rates

et al. 2015

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Abstract. The oxidative capacity of the cloud aqueous phase is investigated during three field campaigns from 2013 to 2014 at the top of the puy de Dôme station (PUY) in France. A total of 41 cloud samples are collected and the corresponding air masses are classified as highly marine, marine and continental. Hydroxyl radical (HO q ) formation rates (R f HO q ) are determined using a photochemical setup (xenon lamp that can reproduce the solar spectrum) and a chemical probe coupled with spectroscopic analysis that can trap all of the generated radicals for each sample. Using this method, the obtained values correspond to the total formation of HO q without its chemical sinks. These formation rates are correlated with the concentrations of the naturally occurring sources of HO q , including hydrogen peroxide, nitrite, nitrate and iron. The total hydroxyl radical formation rates are measured as ranging from approximately 2 × 10 −11 to 4 × 10 −10 M s −1 , and the hydroxyl radical quantum yield formation ( HO q) is estimated between 10 −4 and 10 −2 . Experimental values are compared with modelled formation rates calculated by the model of multiphase cloud chemistry (M2C2), considering only the chemical sources of the hydroxyl radicals. The comparison between the experimental and the modelled results suggests that the photoreactivity of the iron species as a source of HO q is overestimated by the model, and H 2 O 2 photolysis represents the most important source of this radical (between 70 and 99 %) for the cloud water sampled at the PUY station (primarily marine and continental).

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Section: Irradiation Experimentsmentioning

confidence: 99%

A better understanding of hydroxyl radical photochemical sources in cloud waters collected at the puy de Dôme station – experimental versus modelled formation rates

et al. 2015

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“…The rate constant for photolysis, Kpa, found for the actinometer was 0.0042min-1. The quantum yield of the actinometer which we used in our calculations -1 ( qb a = 0.00169 mol Einstein ) was adapted from Dulin and Mill (22).…”

Section: Laboratory Dhotolvsis Eauinmentmentioning

confidence: 99%

A comparative study of the photolytic degradation of octachlorodibenzofuran (OCDF) and octachlorodibenzo-p-dioxin (OCDD)

et al. 1995

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A comparative study of the photolytic degradation of octachlorodibenzofuran (OCDF) and octachlorodibenzo-p-dioxin (OCDD). Wagenaar, W.J.; Boelhouwers, E.J.; de Kok, H.A.M.; Groen, C.P.; van Houtenlaan, C.J.; Govers, H.A.J.; Olie, K.; de Gerlache, J.; de Rooij, C.G. Published in: Chemosphere DOI:10.1016/0045-6535(95)00158-5 Link to publication Citation for published version (APA):Wagenaar, W. J., Boelhouwers, E. J., de Kok, H. A. M., Groen, C. P., van Houtenlaan, C. J., Govers, H. A. J., ... de Rooij, C. G. (1995). A comparative study of the photolytic degradation of octachlorodibenzofuran (OCDF) and octachlorodibenzo-p-dioxin (OCDD). Chemosphere, 31, 2983-2992. DOI: 10.1016/0045-6535(95)00158-5 General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. ABSTRACT Photolysis at 290 nm and higher wavelengths of octachlorodibenzofuran (OCDF) and octachlorodibenzo-p-dioxin (OCDD) was studied in three organic solvents hexane, 1,4-dioxane and methanol. It appeared that the degradation kinetics strongly depended on the type of solvent. OCDD degraded fastest in hexane, whereas OCDF degraded fastest in methanol. Less than 5% of the total loss of OCDD degraded by reductive dechlorination, with preferential loss of chlorine atoms at the 1 or 9 positions. 35 to 50% of the total loss of OCDF degraded via reductive dechlorination, with preferential loss of lateral chlorine. OCDF degraded faster than OCDD in all studied solvents.Photolysis at 290 nm and higher wavelengths of OCDD and OCDF adsorbed onto alumina impregnated with copper (alumina/Cu) in the presence of natural and distilled water was also investigated. Under these more relevant environmental aquatic conditions, photolysis of OCDD and OCDF was much slower than photolysis in the studied organic solvents. Significant loss was only found for OCDF. A part of the loss of OCDF could be explained by reductive dechlorination; the results suggested that other mechanisms of degradation occurred in addition to reductive dechlorination.All photolysis experiments showed that OCDF was photochemically less stable than OCDD. INTRODUCTION.In general, polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are

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“…These have often been complex and unwieldy making them more suitable for use by experts in well-controlled situations than for use under field conditions (Phillips 1983). Photochemical reactions which produce calorimetric or other measurable responses have also been used (Parker 1953;Marwaha et al 1980;Dulin and Mill 1982;Phillips 1983). A great deal of effort has concentrated on the role of UV in producing sunburn in humans.…”

Section: Acknowledgmentsmentioning

confidence: 99%

The measurement and penetration of ultraviolet radiation into tropical marine water

Fleischmann

1989

Limnology & Oceanography

146

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An inexpensive, easily deployed polymer film was used to measure the penetration of ultraviolet (UV) radiation in nearshore tropical water. Measurements were made to a depth of 25 m in Discovery Bay, Jamaica, with a UV-sensitive polymer film in which o-nitrobenzaldehyde is converted to o-nitrosobenzoic acid. The film is sensitive in the range of 400-300 nm. UV radiation ranged from 5 pmol quanta s-l m-2 at the surface to 0.05 at 25 m. The diffuse attenuation coefficient (k) varied between 2.6 and 0.09 m-l with an average of 0.33 m-l. Diurnal measurements of UV at 1 m showed the shape of the curve to be similar to that of surface photosynthetically active radiation, with a maximum at 1200 hours. Integrated measurements ofUV are useful in conjunction with the response of aquatic organisms to changes in this radiation.This paper describes the use of a film actinometer to measure penetration of ultraviolet (UV) radiation into clear marinc waters. The film has the advantage of being sensitive over almost the entire range of solar UV radiation reaching the earth's surface. This method offers a suitable way in which to make field measurements that may then be related to biological processes or used as descriptors of a particular water type.The measurement of solar radiation is of concern both to physicists interested in its inherent properties of penetration through the earth's atmosphere and waters and to biologists who study the effects of radiant energy on organic processes such as photosynthesis, development, and behavior. An important component of the solar spectrum is UV radiation which is subdivided somewhat arbitrarily into three groups: UV-A (400-320 nm), UV-B (320-280 nm), and UV-C (280-200 nm). UV is high energy radiation and therefore produces disproportionate biological effects relative to its 5% ' Current

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Development and evaluation of sunlight actinometers

Cited by 313 publications

References 4 publications

A better understanding of hydroxyl radical photochemical sources in cloud waters collected at the puy de Dôme station – experimental versus modelled formation rates

A better understanding of hydroxyl radical photochemical sources in cloud waters collected at the puy de Dôme station – experimental versus modelled formation rates

A comparative study of the photolytic degradation of octachlorodibenzofuran (OCDF) and octachlorodibenzo-p-dioxin (OCDD)

The measurement and penetration of ultraviolet radiation into tropical marine water

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