The role of irradiation source setups and indirect phototransformation: Kinetic aspects and the formation of transformation products of weakly sunlight-absorbing pesticides

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@article{85701553393f4a57abea97b827d02580,
title = "The role of irradiation source setups and indirect phototransformation: Kinetic aspects and the formation of transformation products of weakly sunlight-absorbing pesticides",
abstract = "In this study, emission spectra of three different commonly used xenon irradiation sources were analyzed and compared for the first time to ascertain the most suitable setup to simulate natural solar radiation. In order to demonstrate setup differences, absolute photon fluxes of irradiation sources were received by actinometry. Verification was done by measuring quantum yields of the model compounds Penconazole, Terbutryn, and Mecoprop in every setup. Differences regarding kinetic aspects and the formation of transformation products (TPs) was evaluated by analyzing direct phototransformation and additionally photolysis in presence of Nitrate as a photosensitizer in one irradiation setup (optical bench). Results showed that a precise setup characterization is needed to estimate whether irradiation sources are suitable to simulate terrestrial sunlight. This was found to be especially important for weakly sunlight-absorbing substances. In comparison with direct photolysis, indirect photolysis led to an enhancement of degradation rate constants for all substances and in case of Mecoprop to different types of TPs that were formed during irradiation. This study underlined that there are big knowledge gaps regarding irradiation sources setups and conditions. It is therefore absolutely necessary to consider those factors while simulating substance degradation and the TP formation under environmental conditions.",
keywords = "Quantum yields, Setup comparison, Simulated sunlight, Spectral overlap, Transformation products, Chemistry",
author = "Birte Hensen and Oliver Olsson and Klaus K{\"u}mmerer",
year = "2019",
month = dec,
day = "10",
doi = "10.1016/j.scitotenv.2019.133808",
language = "English",
volume = "695",
journal = "Science of the Total Environment",
issn = "0048-9697",
publisher = "Elsevier B.V.",

}

RIS

TY - JOUR

T1 - The role of irradiation source setups and indirect phototransformation

T2 - Kinetic aspects and the formation of transformation products of weakly sunlight-absorbing pesticides

AU - Hensen, Birte

AU - Olsson, Oliver

AU - Kümmerer, Klaus

PY - 2019/12/10

Y1 - 2019/12/10

N2 - In this study, emission spectra of three different commonly used xenon irradiation sources were analyzed and compared for the first time to ascertain the most suitable setup to simulate natural solar radiation. In order to demonstrate setup differences, absolute photon fluxes of irradiation sources were received by actinometry. Verification was done by measuring quantum yields of the model compounds Penconazole, Terbutryn, and Mecoprop in every setup. Differences regarding kinetic aspects and the formation of transformation products (TPs) was evaluated by analyzing direct phototransformation and additionally photolysis in presence of Nitrate as a photosensitizer in one irradiation setup (optical bench). Results showed that a precise setup characterization is needed to estimate whether irradiation sources are suitable to simulate terrestrial sunlight. This was found to be especially important for weakly sunlight-absorbing substances. In comparison with direct photolysis, indirect photolysis led to an enhancement of degradation rate constants for all substances and in case of Mecoprop to different types of TPs that were formed during irradiation. This study underlined that there are big knowledge gaps regarding irradiation sources setups and conditions. It is therefore absolutely necessary to consider those factors while simulating substance degradation and the TP formation under environmental conditions.

AB - In this study, emission spectra of three different commonly used xenon irradiation sources were analyzed and compared for the first time to ascertain the most suitable setup to simulate natural solar radiation. In order to demonstrate setup differences, absolute photon fluxes of irradiation sources were received by actinometry. Verification was done by measuring quantum yields of the model compounds Penconazole, Terbutryn, and Mecoprop in every setup. Differences regarding kinetic aspects and the formation of transformation products (TPs) was evaluated by analyzing direct phototransformation and additionally photolysis in presence of Nitrate as a photosensitizer in one irradiation setup (optical bench). Results showed that a precise setup characterization is needed to estimate whether irradiation sources are suitable to simulate terrestrial sunlight. This was found to be especially important for weakly sunlight-absorbing substances. In comparison with direct photolysis, indirect photolysis led to an enhancement of degradation rate constants for all substances and in case of Mecoprop to different types of TPs that were formed during irradiation. This study underlined that there are big knowledge gaps regarding irradiation sources setups and conditions. It is therefore absolutely necessary to consider those factors while simulating substance degradation and the TP formation under environmental conditions.

KW - Quantum yields

KW - Setup comparison

KW - Simulated sunlight

KW - Spectral overlap

KW - Transformation products

KW - Chemistry

UR - http://www.scopus.com/inward/record.url?scp=85070573657&partnerID=8YFLogxK

U2 - 10.1016/j.scitotenv.2019.133808

DO - 10.1016/j.scitotenv.2019.133808

M3 - Journal articles

C2 - 31426002

AN - SCOPUS:85070573657

VL - 695

JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 0048-9697

M1 - 133808

ER -

DOI