GC-MS and LC-MS evaluation of pesticide degradation products generated through advanced oxidation processes: An overview

Agüera, Ana; Fernández‐Alba, Amadeo R.

doi:10.1051/analusis:199826060123

Cited by 26 publications

(6 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Despite the widespread use of GC-MS, in the majority of cases there are serious drawbacks due to difficulties in direct water injection, the formation of thermal artifacts, loss of polar compounds, etc. Many of the characteristic GC-MS limitations can be overcome by LC-MS with atmospheric pressure ionization (API) interfaces, which provides fast detailed information about the appear ance (see Figure ) and evolution of the DPs formed during water treatment ( − ).…”

Section: Resultsmentioning

confidence: 99%

Photocatalytic Treatment of Diuron by Solar Photocatalysis: Evaluation of Main Intermediates and Toxicity

Malato

Cáceres

Fernández‐Alba

et al. 2003

Environ. Sci. Technol.

Self Cite

154

View full text Add to dashboard Cite

The technical feasibility, mechanisms, and performance of degradation of aqueous diuron (22 mg/L) have been studied at pilot scale in two well-defined photocatalytic systems of special interest because natural UV light can be used: heterogeneous photocatalysis with titanium dioxide and homogeneous photocatalysis by photo-Fenton. Equivalent pilot-scale (made up of Compound Parabolic Collectors (CPCs) specially designed for solar photocatalytic applications) and field conditions used for both allowed adequate comparison of the degree of mineralization and toxicity achieved as well as the transformation products generated en route to mineralization by both systems. Total disappearance of diuron is attained by both phototreatments in 45 min. 100% of chlorine was recovered as chloride, but total recovery of nitrogen as inorganic ions was not attained. 90% of mineralization was reached after 200 min of photocatalytic treatment, but toxicity measured by two different bioassays (Daphnia magna and a Microalga) was reduced to below the threshold (EC50%) in a shorter time. Transformation products evaluated by LC-IT-MS by direct injection of the samples were the same in both cases. The main differences between the two processes were in the amount of transformation products (DPs) generated, not in the DPs detected, which were always the same.

show abstract

Section: Resultsmentioning

confidence: 99%

Photocatalytic Treatment of Diuron by Solar Photocatalysis: Evaluation of Main Intermediates and Toxicity

Malato

Cáceres

Fernández‐Alba

et al. 2003

Environ. Sci. Technol.

Self Cite

154

View full text Add to dashboard Cite

show abstract

“…In this in-depth pilot-scale study, diclofenac in aqueous media was degraded by photo-Fenton to identify the intermediate degradation products (DPs) formed and establish the reaction pathway. Gas and liquid chromatogra phy−mass spectrometry (GC/MS and LC/MS) techniques, as a valid simple approach to exhaustive study and identification of unknowns ( − ), were employed for this. In addition to the superior identification capability of the GC/EI-MS full scan mass spectra, LC/MS has become the preferred analytical instrument for analyzing relatively polar and nonvolatile organic molecules without derivation.…”

Section: Introductionmentioning

confidence: 99%

Photo-Fenton Degradation of Diclofenac: Identification of Main Intermediates and Degradation Pathway

Pérez-Estrada

Malato

Gernjak

et al. 2005

Environ. Sci. Technol.

375

View full text Add to dashboard Cite

In recent years, the presence of pharmaceuticals in the aquatic environment has been of growing interest. These new contaminants are important because many of them are not degraded under the typical biological treatments applied in the wastewater treatment plants and represent a continuous input into the environment. Thus, compounds such as diclofenac are present in surface waters in all Europe and a crucial need for more enhanced technologies that can reduce its presence in the environment has become evident. In this sense, advanced oxidation processes (AOPs) represent a good choice for the treatment of hazardous nonbiodegradable pollutants. This work deals with the solar photodegradation of diclofenac, an antiinflammatory drug, in aqueous solutions by photo-Fenton reaction. A pilot-scale facility using a compound parabolic collector (CPC) reactor was used for this study. Results obtained show rapid and complete oxidation of diclofenac after 60 min, and total mineralization (disappearance of dissolved organic carbon, DOC) after 100 min of exposure to sunlight. Although diclofenac precipitates during the process at low pH, its degradation takes place in the homogeneous phase governed by a precipitation-redissolution-degradation process. Establishment of the reaction pathway was made possible by a thorough analysis of the reaction mixture identifying the main intermediate products generated. Gas chromatography-mass spectrometry (GC/ MS) and liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOF-MS) were used to identify 18 intermediates, in two tentative degradation routes. The main one was based on the initial hydroxylation of the phenylacetic acid moiety in the C-4 position and subsequent formation of a quinone imine derivative that was the starting point for further multistep degradation involving hydroxylation, decarboxylation, and oxidation reactions. An alternative route was based on the transient preservation of the biphenyl amino moiety that underwent a similar oxidative process of C-N bond cleavage. The proposed degradation route differs from those previously reported involving alternative degradation processes (ozonization, UV/H2O2, or photolysis), indicating that diclofenac degradation follows different pathways, depending on the treatment applied.

show abstract

“…[1][2][3][4][5] Advanced oxidation processes (AOPs) are widely studied because they are fast, clean, and effective for decontaminating polluted water. 6 UV irradiation, in combination with oxidants or catalysts, as a subset of AOPs, has been considered an effective and practical method to degrade organic compounds in the aquatic environment. 7,8 Catalysts play a significant role in environmentally friendly and cost-effective processes.…”

Section: Introductionmentioning

confidence: 99%

Mechanistic investigation of the photocatalytic activity of PEDOT for aqueous contaminant removal: the role of iron and hydroxyl radicals

Jasemizad,

Malmström,

Padhye

2024

Environ. Sci.: Water Res. Technol.

View full text Add to dashboard Cite

show abstract

GC-MS and LC-MS evaluation of pesticide degradation products generated through advanced oxidation processes: An overview

Cited by 26 publications

References 19 publications

Photocatalytic Treatment of Diuron by Solar Photocatalysis: Evaluation of Main Intermediates and Toxicity

Photocatalytic Treatment of Diuron by Solar Photocatalysis: Evaluation of Main Intermediates and Toxicity

Photo-Fenton Degradation of Diclofenac: Identification of Main Intermediates and Degradation Pathway

Mechanistic investigation of the photocatalytic activity of PEDOT for aqueous contaminant removal: the role of iron and hydroxyl radicals

Contact Info

Product

Resources

About