Determination of optical parameters for light penetration in particulate materials and soils with diffuse reflectance (DR) spectroscopy

Schober, Lars; Löhmannsröben, Hans‐Gerd

doi:10.1039/b004127k

Cited by 22 publications

(8 citation statements)

References 9 publications

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“…One study suggested that photolysis might play a role in degradation of tetracyclines and TYL on the surfaces of agricultural soils [47]. However, light only penetrates the soil from a few microns to a few millimeters, limiting photolysis to a very small portion of the soil mass [48], so it is unlikely to be a major process in antimicrobial degradation. It is a subject of debate whether microbial processes could play an important role in their degradation ([49,50]; for [49], see http://abstracts.co.allenpress.com/pweb/setaceu2003/document/?ID=22200).…”

Section: Discussionmentioning

confidence: 99%

Dissipation kinetics and mobility of chlortetracycline, tylosin, and monensin in an agricultural soil in Northumberland County, Ontario, Canada

Carlson

Mabury

2006

Environmental Toxicology and Chemistry

127

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A robust high-throughput method was refined to extract three growth-promoting antibiotics, tylosin (TYL), chlortetracycline (CTC), and monensin (MON), from soil. Analysis was performed by electrospray liquid chromatography tandem mass spectrometry. Soil dissipation rate studies were performed in a farm field soil for antibiotics applied with and without manure. Tylosin, CTC, and MON followed first-order dissipation kinetics with half-lives of 4.5, 24, and 3.3 d, respectively, with the addition of manure and 6.1, 21, and 3.8 d, respectively, without manure. Manure application significantly increased TYL dissipation rate, perhaps because of the introduced microbial flora, but had no significant effect on CTC or MON. Monensin dissipation half-life was found to be much shorter in the field study than in a controlled laboratory study, perhaps because of differences in microbial communities. The antimicrobials were not highly mobile. Chlortetracycline was the only antibiotic detected at 25 to 35 cm depth and only up to 2% of the initial concentration in a sandy loam soil. These antibiotics are therefore expected to degrade primarily in agricultural soils before moving to greater depths or to groundwater in significant concentrations in most agricultural systems.

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Section: Discussionmentioning

confidence: 99%

Dissipation kinetics and mobility of chlortetracycline, tylosin, and monensin in an agricultural soil in Northumberland County, Ontario, Canada

Carlson

Mabury

2006

Environmental Toxicology and Chemistry

127

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“…Light propagation in soil is important for the quantification of chemical and biological processes such as photochemical transformation of pesticides or other organic compounds (Hebert & Miller, 1990; Balmer et al ., 2000) (wavelength range 290–500 nm), and germination of seeds (Woolley & Stoller, 1978; Bliss & Smith, 1985; Benvenuti, 1995) (wavelength range 660–730 nm). It is also critical in measurement techniques such as laser‐induced fluorescence spectroscopy (Schober & Löhmannsröben, 2000) and remote sensing of soils because information is needed about the depth from which the measured signal originates. Therefore, it is necessary to know the light penetration depth in the soil and, for diffuse reflectance spectroscopic studies, to know from which depth spectroscopic information arises (information depth).…”

Section: Introductionmentioning

confidence: 99%

Light penetration in soil and particulate minerals

Ciani

Goss

Schwarzenbach

2005

European J Soil Science

149

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Knowledge of light penetration in soils is of particular interest for photolytic degradation of pesticides, for laser-induced fluorescence spectroscopy and remote sensing, and for understanding better the germination of seeds. To date little information has been available in the literature on this topic. In this paper light penetration in soils is determined successfully using diffuse reflectance and transmittance spectroscopy and the relatively simple Kubelka-Munk model. Using the latter model of light propagation in turbid media, the optical properties of kaolinite, montmorillonite, barium sulphate, goethite and 19 different soils were determined in the wavelength range 275-700 nm. In particular, the light absorption coefficient, k, and light scattering coefficient, s, were determined. The depth at which the light intensity at the surface is reduced by 99% (light penetration depth) and the depth of the sample contributing to the measured reflected radiation (information depth) could also be calculated from k and s. For kaolinite, the light penetration depth ranged between 10 and 200 mm for wavelengths between 275 and 700 nm, respectively; the information depth was between 5 and 80 mm. For soils, the penetration depth was in the range 17-110 mm at 275 nm and 120-300 mm at 700 nm, and the information depth was in the range 8-60 mm at 275 nm and 60-175 mm at 700 nm. Hence, the information depth is about half the penetration depth for media with reflectance smaller than 0.7 (e.g. soils). For dry soils, an empirical relationship was established between the light absorption coefficient and the amount of particlesize fractions. The effect of water content was also investigated: addition of water to kaolinite reduced its scattering coefficients, whereas the absorption coefficient was hardly affected. For the soils, addition of water had a more complex mode of action affecting both absorption and scattering coefficients. With the measured optical properties of dry minerals and soils it is possible to calculate light intensity profiles with depth and to quantify photochemical processes occurring in these media.

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“…In general, Reticulitermes termites encounter little or no UV light in their natural habitats (Schober and Lohmannsroben 2000), and it is possible that the ßu-orescence of norharmane is incidental to its biological role. However, the ßuorescence surrounding the eyes of Reticulitermes workers shows that these areas are opaque to UV light and may be allowing exposure of UV photosensors in the head.…”

Section: Discussionmentioning

confidence: 99%

Isolation and Characterization of Norharmane from <I>Reticulitermes</I> Termites (Isoptera: Rhinotermitidae)

Siderhurst¹,

James²,

Rithner³

et al. 2005

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Determination of optical parameters for light penetration in particulate materials and soils with diffuse reflectance (DR) spectroscopy

Cited by 22 publications

References 9 publications

Dissipation kinetics and mobility of chlortetracycline, tylosin, and monensin in an agricultural soil in Northumberland County, Ontario, Canada

Dissipation kinetics and mobility of chlortetracycline, tylosin, and monensin in an agricultural soil in Northumberland County, Ontario, Canada

Light penetration in soil and particulate minerals

Isolation and Characterization of Norharmane from <I>Reticulitermes</I> Termites (Isoptera: Rhinotermitidae)

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