Electrochemical Abatement of Atrazine Solutions Using an Undivided Stirred Tank Cell with Pt or BDD Anode

Nowadays, the increasing pollution of natural water effluents with herbicides, such as atrazine (ATZ, 2-chloro-4-ethylamino-6-isopropylamino-s-triazine), is an emerging problem that has not received the sufficient attention. This work presents a study on ATZ degradation under an electrochemical advanced oxidation process (EAOP), such as anodic oxidation (AO). The degradation of 175 mL of 10 and 40 mg L-1 ATZ solutions was studied using Pt or BDD as anode. The assays were made with a stirred tank cell, using a supporting electrolyte of 0.050 mM of Na2SO4 at pH 3.0 by applying 0.18, 0.27 and 0.37 A cm-2. The degradation rate increased by increasing current density, regardless of the anode employed. Greater amounts of ATZ were removed at higher organic load. The pesticide decay always obeyed a pseudo-first-order kinetics. A high degradation efficiency of 97%-99% was obtained by the more powerful AO-BDD process at 0.37 A cm-2. High performance liquid chromatography (HPLC) was used to follow the evolution of major oxidation products by AO-BDD, such as desethyl atrazine, desethyl desisopropyl atrazine and cyanuric acid.

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Water ingestion during swimming activities in a pool: A pilot study

Journal of Water and Health ◽

10.2166/wh.2006.0026 ◽

2006 ◽

Vol 4 (4) ◽

pp. 425-430 ◽

Cited By ~ 142

Author(s):

Alfred P. Dufour ◽

Otis Evans ◽

Thomas D. Behymer ◽

Ricardo Cantú

Keyword(s):

High Performance ◽

Cyanuric Acid ◽

The Body ◽

Swimming Activity ◽

Swimming Pool ◽

Urinary Proteins ◽

Analytical Methodology ◽

Water Ingestion ◽

Pool Water ◽

Swimming Pool Water

Chloroisocyanurates are commonly added to outdoor swimming pools to stabilize chlorine disinfectants. The chloroisocyanurates decompose slowly to release chlorine and cyanuric acid. Studies conducted to determine if the chloroisocyanurates might be toxic to swimmers showed that they were not and that ingested cyanuric acid passed through the body unmetabolized. This fact was used to determine the amount of water swallowed during swimming activity. Fifty-three recreational swimmers, using a community swimming pool disinfected with cyanuric acid stabilized chlorine, participated in the study. The participants did not swim on the day before or after the test swim. The swimmers were asked to actively swim for at least 45 minutes and to collect their urine for the next 24 hours. Cyanuric acid was measured in pool water using high performance liquid chromatography and porous graphitic carbon columns with UV detection. The urine sample assay required a clean-up procedure to remove urinary proteins and interfering substances. Results of the study indicate that non-adults ingest about twice as much water as adults during swimming activity. The average amount of water swallowed by non-adults and adults was 37 ml and 16 ml, respectively. The design for this study and the analytical methodology used to assay cyanuric acid in swimming pool water and human urine were effective for measuring the volume of water swallowed during swimming activity.

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Reversed-phase gradient high-performance liquid chromatography of procyanidins and their oxidation products in ciders and wines, optimised by Snyder's procedures

Journal of Chromatography A ◽

10.1016/s0021-9673(00)81050-x ◽

1980 ◽

Vol 194 (1) ◽

pp. 62-68 ◽

Cited By ~ 45

Author(s):

Andrew G.H. Lea

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

High Performance ◽

Reversed Phase ◽

Oxidation Products ◽

Phase Gradient

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Potentiation of leukotriene production following sequestration of neutrophils in isolated lungs: indirect evidence for intercellular leukotriene A4 transfer

Blood ◽

10.1182/blood.v72.5.1687.1687 ◽

1988 ◽

Vol 72 (5) ◽

pp. 1687-1692 ◽

Cited By ~ 34

Author(s):

F Grimminger ◽

M Menger ◽

G Becker ◽

W Seeger

Keyword(s):

High Performance ◽

Calcium Ionophore ◽

Indirect Evidence ◽

Oxidation Products ◽

Combined System ◽

Hydrolysis Products ◽

On Line ◽

Isolated Lungs ◽

Leukotriene A4

Abstract Granulocyte (polymorphonuclear leukocyte, PMN) sequestration in the microvascular bed with release of different mediators has been implicated in the pathogenesis of inflammatory and allergic disorders in many organs including the lung. In the present study, we investigated the profile and quantity of leukotriene (LT) generation in isolated blood-free perfused rabbit lungs, in isolated PMNs in vitro and in rabbit lungs, following administration of PMNs, mimicking pulmonary leukostasis. Following stimulation with increasing concentrations of the calcium ionophore A 23137 (0.1 to 2 mumol/L), LTs were detected in the buffer fluid by their chromatographic mobility in different high-performance liquid chromatography (HPLC) systems, by on- line peak spectrum analysis, and by post-HPLC radioimmunoassay (RIA). In isolated lungs, a dose-dependent generation of cysteinyl LTs greater than LTB4, in the complete absence of omega-oxidation products of LTB4 as well as nonenzymatic hydrolysis products of LTA4, was evoked. PMNs in vitro showed a typical profile of LT liberation (LTB4, 20-OH-, and COOH-LTB4, nonenzymatic LTA4 metabolites). In the model of pulmonary leukostasis, the presence of omega-oxidation products of LTB4 indicated metabolic integrity of the trapped PMNs. Nonenzymatic hydrolysis products of LTA4 were, however, not detected in the combined system, whereas the cysteinyl LTs increased markedly. This profile suggests intercellular transfer of PMN-derived LTA4 to lung cells in the microenvironment. In addition, at 2 mumol/L A23187, the sum of all LTA4- derived products surpassed the arithmetic sum of the isolated preparations more than threefold. This potentiation of an LT generation under conditions of pulmonary leukostasis may be of biologic significance for amplification of inflammatory events.

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Influence of Oxygen-Containing Sulfur Flavor Molecules on the Stability of β-Carotene under UVA Irradiation

Molecules ◽

10.3390/molecules24020318 ◽

2019 ◽

Vol 24 (2) ◽

pp. 318 ◽

Cited By ~ 1

Author(s):

Gong-Liang Zhang ◽

Hong-Yan Wu ◽

Ying Liang ◽

Jie Song ◽

Wei-Qi Gan ◽

...

Keyword(s):

Sulfur Atom ◽

Critical Role ◽

Oxidation Products ◽

First Order ◽

Uva Irradiation ◽

First Order Kinetics ◽

Dynamic Degradation ◽

The Stability ◽

Ethanol System ◽

Β Carotene

The influence of 11 kinds of oxygen-containing sulfur flavor molecules was examined on β-carotene stability under UVA irradiation in ethanol system. Both the effects of sulfides on dynamic degradation of β-carotene and the relation between structure and effect were investigated. The oxidation products of β-carotene accelerated by sulfides under UVA irradiation were also identified. The results indicated that the disulfides had more obvious accelerative effects on the photodegradation of β-carotene than mono sulfides. The degradation of β-carotene after methyl (2-methyl-3-furyl) disulfide (MMFDS), methyl furfuryl disulfide (MFDS) and bis(2-methyl-3-furyl) disulfide (BMFDS) exposure followed first-order kinetics. Furan-containing sulfides such as MMFDS and BMFDS showed more pronounced accelerative effects than their corresponding isomers. The oxidation products were identified as 13-cis-β-carotene, 9,13-di-cis-β-carotene and all-trans-5,6-epoxy-β-carotene. These results suggest that both the sulfur atom numbers and the furan group in oxygen-containing sulfides play a critical role in the photooxidation of β-carotene.

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Comparative study of microbiological, chemical and sensory properties of kefirs produced in Estonia, Latvia and Lithuania

Journal of Dairy Research ◽

10.1017/s0022029915000710 ◽

2016 ◽

Vol 83 (1) ◽

pp. 89-95 ◽

Cited By ~ 3

Author(s):

Dea Anton ◽

Piret Raudsepp ◽

Mati Roasto ◽

Kadrin Meremäe ◽

Sirje Kuusik ◽

...

Keyword(s):

High Performance ◽

Ion Trap ◽

Chemical Properties ◽

Principal Component ◽

Bacterial Count ◽

Starter Cultures ◽

Oxidation Products ◽

Total Bacterial Count ◽

Codex Standard ◽

Primary Oxidation

In the current study the microbiological, sensory and chemical properties of 24 kefirs (12 producers) from Estonian, Latvian and Lithuanian retail market were determined using gas chromatography (GC), high performance liquid chromatography (HPLC-MS/MS-Q-TOF and LC-ion trap MS/MS), spectrophotometry and other methods. Antihypertensive, angiotensin-converting enzyme (ACE) inhibiting, antioxidant and antibacterial peptides were found in the kefir samples. According to the results of principal component analysis of 200 most abundant compounds obtained with HPLC-MS/MS-Q-TOF analysis, Estonian kefirs differed from the rest. Kefirs of Latvian and Lithuanian origin showed similarities in several characteristics, probably related to the starter cultures and technological processes. The fatty acids composition of all Baltic kefirs was uniform. The antioxidant capacity of the kefirs varied slightly, whereas intermediate positive correlation (r= 0·32,P< 0·05) was found between antioxidativity and total bacterial count. The lipid oxidation level, estimated as the content of linoleic and oleic acid primary oxidation products, oxylipins, was very low in all studied kefirs. Only one third of analysed kefirs met the requirements of the minimum sum of viable microorganisms, indicated in the Codex Standard for Fermented Milks.

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