TY - JOUR

T1 - Identification of ozonation by-products of 4- and 5-methyl-1H-benzotriazole during the treatment of surface water to drinking water

AU - Müller, A.

AU - Weiss, S.C.

AU - Beißwenger, J.

AU - Leukhardt, H.G.

AU - Schulz, W.

AU - Seitz, W.

AU - Ruck, W.K.L.

AU - Weber, W.H.

N1 - MEDLINE® is the source for the MeSH terms of this document.

PY - 2012/3/1

Y1 - 2012/3/1

N2 - During the treatment of surface water to drinking water, ozonation is often used for disinfection and to remove organic trace substances, whereby oxidation by-products can be formed. Here we use the example of tolyltriazole to describe an approach for identifying relevant oxidation by-products in the laboratory and subsequently detecting them in an industrial-scale process. The identification process involves ozonation experiments with pure substances at laboratory level (concentration range mgL -1). The reaction solutions from different ozone contact times were analyzed by high performance liquid chromatography - quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) in full scan mode. Various approaches were used to detect the oxidation by-products: (i) target searches of postulated oxidation by-products, (ii) comparisons of chromatograms (e.g., UV/VIS) of the different samples, and (iii) color-coded abundance time courses (kinetic) of all detected compounds were illustrated in a kind of a heat map. MS/MS, H/D exchange, and derivatization experiments were used for structure elucidation for the detected by-product. Due to the low contaminant concentrations (ngL -1-range) of contaminants in the untreated water, the conversion of results from laboratory experiments to an industrial-scale required the use of HPLC-MS/MS with sample enrichment (e.g., solid phase extraction.) In cases where reference substances were not available or oxidation by-products without clear structures were detected, reaction solutions from laboratory experiments were used to optimize the analytical method to detect ngL -1 in the samples of the industrial processes. We exemplarily demonstrated the effectiveness of the methodology with the industrial chemicals 4- and 5-methyl-1H-benzotriazole (4- and 5-MBT) as an example. Moreover, not only did we identify several oxidation by-products in the laboratory experiments tentatively, but also detected three of the eleven reaction products in the outlet of the full-scale ozonation unit.

AB - During the treatment of surface water to drinking water, ozonation is often used for disinfection and to remove organic trace substances, whereby oxidation by-products can be formed. Here we use the example of tolyltriazole to describe an approach for identifying relevant oxidation by-products in the laboratory and subsequently detecting them in an industrial-scale process. The identification process involves ozonation experiments with pure substances at laboratory level (concentration range mgL -1). The reaction solutions from different ozone contact times were analyzed by high performance liquid chromatography - quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) in full scan mode. Various approaches were used to detect the oxidation by-products: (i) target searches of postulated oxidation by-products, (ii) comparisons of chromatograms (e.g., UV/VIS) of the different samples, and (iii) color-coded abundance time courses (kinetic) of all detected compounds were illustrated in a kind of a heat map. MS/MS, H/D exchange, and derivatization experiments were used for structure elucidation for the detected by-product. Due to the low contaminant concentrations (ngL -1-range) of contaminants in the untreated water, the conversion of results from laboratory experiments to an industrial-scale required the use of HPLC-MS/MS with sample enrichment (e.g., solid phase extraction.) In cases where reference substances were not available or oxidation by-products without clear structures were detected, reaction solutions from laboratory experiments were used to optimize the analytical method to detect ngL -1 in the samples of the industrial processes. We exemplarily demonstrated the effectiveness of the methodology with the industrial chemicals 4- and 5-methyl-1H-benzotriazole (4- and 5-MBT) as an example. Moreover, not only did we identify several oxidation by-products in the laboratory experiments tentatively, but also detected three of the eleven reaction products in the outlet of the full-scale ozonation unit.

KW - Chemistry

KW - HPLC-QTOF-MS

KW - HPTLC/AMD-MS

KW - Ozonation by-products

KW - Tolyltriazole

KW - Water purification

UR - http://www.scopus.com/inward/record.url?scp=84855320820&partnerID=8YFLogxK

U2 - 10.1016/j.watres.2011.11.033

DO - 10.1016/j.watres.2011.11.033

M3 - Journal articles

C2 - 22154110

AN - SCOPUS:84855320820

VL - 46

SP - 679

EP - 690

JO - Water Research

JF - Water Research

SN - 0043-1354

IS - 3

ER -