Sulfone Products Research Articles

Effect of the Oxygenated Diamond Surface on the Electrochemical Oxidation of DBT and 4,6-DMDBT

Boron-doped diamond (BDD) has been extensively studied by their ability to oxidize a wide range of contaminants in liquid mixtures. These electrodes have a wide potential window margin for water discharge and stability for extended periods of time (1,2). However their electrochemical activity depends on the surface composition and the degree of crystallinity. On the other hand, electrochemical oxidation techniques have received great importance in the electrochemical desulfurization of organic sulfur compounds (3,4). In the present work electrochemical oxidation of DBT and 4,6-DMDBT was studed using BDD electrode in acetonitrile-water medium (electrolyte). Also was studied the oxidation of above compounds mentioned on the preoxygenated diamond surface by VMC, Chronoamperometry and electrolysis at constant potentials. The results showed that the oxygenated species on the surface of the BDD electrode influence the electrode-analyte interactions, the kinetics and the mechanism of the oxidation process. The analysis of the extracts after the electrochemical oxidation of DBT and 4,6-DMDBT by GC / MS and HPLC-MS / MS showed that the oxidation is selective. At potentials lower than 1.75V, the main product is the formation of sulfoxide, while at potentials greater than 1.75V it is the corresponding sulfone. A mixture of sulfoxide, sulfone and other oxidation products was obtained due to the opening of the aromatic ring for potentials greater than 2.0 V and prolonged electrolysis times. Bibliography F. Zhi, H.B. Wang, T. Nakashima, Tata N. Rao, A. Fujishima. J. Phys. Chem. B (2003) 107, 13389-13395P. Chaplina, D. K. Hubler, J. Farrell. Electrochimica Acta 86 (2013) 122-131Méndez-Albores, M. A. González-Fuentes, M. M. Dávila-Jiménez, F. J. González. Journal of Electroanalytical Chemistry 751 (2015) 7–14Lam, G. Li, C. Song, J. Chen, C. Fairbridge, R. Hui, J. Zhang. Fuel Processing Technology 98 (2012) 30-38

Estudio cinético de la reacción de Famotidina S-oxidación utilizando caroato de potasio. Desarrollo y validación del método titrimétrico para la determinación cuantitativa de Famotidina en sustancia pura y preparación médica

Objetivos: Los estudios cinéticos de substancia y medicamento Famotidina (FMT) han sido realizados en las soluciones amortiguadoras en las condiciones de reacción del segundo orden a temperatura de 293 K. Nuevos métodos titrimétricos están descritos para determinar FMT. Materiales y métodos: La substancia y los comprimidos FMT han sido usados en la reacción analítica con KHSO5. El comportamiento cinético ha sido estudiado por el método de yodometría en diferentes ambientes de pH. Resultados: La reacción de oxidación de FMT se estudiaba para el producto del óxido S con pH = 2,0-5,0 y de la sulfona con pH = 7,0-8,4. La reacción a estudiar corresponde al segundo orden general. Las constantes de velocidad de la reacción de la formación de sulfona del óxido S FMT se encuentra en el intervalo de 14,49 a 32 l mol-1 min-1. La FMT fue determinada mediante la medición del exceso de solución estándar del caroata de potasio en la solución amortiguadora con pH 7 dentro de 20 minutos desde el inicio de la reacción, luego el oxidante restante fue determinado por el método de titulación yodométrica. El método titrimétrico se aplica en el diapasón de 1-10 mg, la reacción corresponde a la estequiometría 1: 2 (FMT: KHSO5). El método ha sido validado a la precisión, reproducción, linealidad, robustez y LOQ. El contenido del principio activo es del 99,2 al 100,5%, RSD del 1,09 al 1,70%, LOQ = 0,03 mg / ml para substancia. RSD para comprimidos se encuentra dentro del 1,17 al 2,87%. Conclusión: Han sido optimizadas las condiciones de formación del óxido S de FMT y sulfona. Los métodos elaborados son rápidos, sencillos y baratos y podrán aplicarse para determinar el fármaco de preparación farmacética.

Condensed Tannin Reacts with SO2 during Wine Aging, Yielding Flavan-3-ol Sulfonates.

Numerous monomeric and oligomeric flavanol sulfonation products were observed in 10 wines. Levels of 0.85-20.06 and 0-14.72 mg/L were quantified for two monomeric sulfonated flavan-3-ols and, surprisingly, were generally higher than the well-known native flavan-3-ol monomers. Increasing SO2 levels during wine aging increased the sulfonate-modified flavan-3-ol monomers and dimers along with higher concentrations of native monomers. The results indicate that >10% of SO2 is reacting with the C-4 carbocation, formed from acid cleavage of the interflavan bond, perhaps by a bimolecular SN2-type reaction, and as a reducing agent. In addition, the high SO2 wine had the lowest protein-binding tannin levels, tannin activity, and mean degree of polymerization (mDP), and acidic SO2 treatment of condensed tannin abolishes protein binding. Thus, SO2 changes tannin composition during wine aging, and the substantial formation of sulfonate-modified flavan-3-ols may provide an additional explanation for the reduction in astringency of aged red wines.

The sulfoconjugation of androstenone and dehydroepiandrosterone by human and porcine sulfotransferase enzymes

Porcine sulfotransferase 2A1 (pSULT2A1) is a key enzyme involved in the testicular and hepatic sulfoconjugation of steroids such as dehydroepiandrosterone (DHEA) and potentially androstenone. This latter steroid is a major cause of boar taint, which is an unpleasant off-odour and off-flavour in pork from male pigs. Sulfotransferase 2B1 (pSULT2B1) may also be important, although no direct evidence exists for its involvement in sulfoconjugation of steroids. The purpose of this study was to investigate the sulfoconjugation activity of human and porcine sulfotransferases towards DHEA and androstenone. pcDNA 3.1 vectors expressing porcine (p) SULT2A1, pSULT2B1, human (h) SULT2A1, hSULT2B1a, and hSULT2B1b enzymes were transfected into human embryonic kidney cells. Transfected cells were then incubated with either androstenone or dehydroepiandrosterone (DHEA) in both time-course and enzyme kinetics studies. The production of sulfonates of androstenone metabolites and DHEA sulfonate increased over time for all enzymes with the exception of pSULT2B1. Enzyme kinetics analysis showed that androstenone and DHEA were poor substrates for the human orthologs, hSULT2B1a and hSULT2B1b. Human and porcine SULT2A1 showed substantially different substrate affinities for androstenone (Km 5.8 ± 0.6 µM and 74.1 ± 15.9 µM, respectively) and DHEA (Km 9.4 ± 2.5 µM and 3.3 ± 1.9 µM, respectively). However, these enzymes did show relatively similar sulfonation efficiencies for DHEA (Vmax/Km 50.5 and 72.9 for hSULT2A1 and pSULT2A1, respectively). These results highlight the species differences in sulfonation activity and provide direct evidence, for the first time, suggesting that pSULT2B1 is not involved in sulfonation of either androstenone metabolites or DHEA.

Selective Synthesis of Ortho-Substituted 2-Aryl-3-phenyl-1,3-thiazolidin-4-one Sulfoxides and Sulfones by S-Oxidation with Oxone®

S-oxidation of 2-aryl-3-phenyl-1,3-thiazolidin-4-ones with Oxone® was investigated. For all compounds evaluated, selective oxidation to the sulfoxide was realized using 3 equivalents of Oxone® at room temperature. Attempts to selectively prepare the sulfones of ortho-substituted 2-aryl-3-phenyl-1,3-thiazolidin-4-ones at high temperature by increasing the equivalents of Oxone® used were typically unsuccessful. These results contrast significantly with ortho-substituted 2-aryl-3-cyclohexyl-1,3-thiazolidin-4-ones evaluated previously. The extent of this selectivity was affected by the substituent and its position on the C2 aromatic ring. The ratio of the sulfoxide and sulfone products was quantified by isolating the products by liquid chromatography.Please find the scheme in PDF file.

Selective Synthesis of Substituted 3-Aryl-2-phenyl-1,3-thiazolidin-4-one Sulfoxides and Sulfones by S-Oxidation with Oxone

S-oxidation of 3-aryl-2-phenyl-1,3-thiazolidin-4-ones with Oxone® was investigated. For all compounds evaluated, selective oxidation to the sulfoxide was realized using 3 equivalents of Oxone® at room temperature. Alternatively, the sulfone was prepared selectively in most of the compounds evaluated at high temperature by increasing the equivalents of Oxone® used; the extent of this selectivity was affected by the substituent and its position on the N3 aromatic ring. The ratio of the sulfoxide and sulfone products was quantified by isolating the products by liquid chromatography.

Kinetic analysis of aerobic biotransformation pathways of a perfluorooctane sulfonate (PFOS) precursor in distinctly different soils

With the phaseout of perfluorooctane sulfonate (PFOS) production in most countries and its well known recalcitrance, there is a need to quantify the potential release of PFOS from precursors previously or currently being emitted into the environment. Aerobic biodegradation of N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE) was monitored in two soils from Indiana, USA: an acidic forest silt loam (FRST-48, pH = 5.5) and a high pH agricultural loam (PSF-49, pH = 7.8) with similar organic carbon contents (2.4 and 2.6%) for 210 d and 180 d, respectively. At designated times, triplicate samples were sacrificed for which headspace samples were taken followed by three sequential extractions. Extracts were analyzed using HPLC-tandem mass spectrometry. Measured profiles of EtFOSE degradation and generation/degradation of subsequent metabolites were fitted to the Indiana soils data as well as to a previously published data set for a Canadian soil using an R-based model (KinGUII) to explore pathways and estimate half-lives (t1/2) for EtFOSE and metabolites. EtFOSE degradation ranged from a few days to up to a month. PFOS yields ranged form 1.06–5.49 mol% with the alkaline soils being four to five times higher than the acidic soil. In addition, a direct pathway to PFOS had to be invoked to describe the early generation of PFOS in the Canadian soil. Of all metabolites, the sulfonamidoacetic acids were the most persistent (t1/2 ≥ 3 months) in all soils. We hypothesized that while pH-pKa dependent speciation may have impacted rates, differences in microbial communities between the 3 soils arising from varied soil properties including pH, nutrient levels, soil management, and climatic regions are likely the major factors affecting pathways, rates, and PFOS yields.

Aerobic biodegradation of 2 fluorotelomer sulfonamide-based aqueous film-forming foam components produces perfluoroalkyl carboxylates.

The biodegradation of 2 common fluorotelomer surfactants used in aqueous film forming foams (AFFFs), 6:2 fluorotelomer sulfonamide alkylamine (FTAA) and 6:2 fluorotelomer sulfonamide alkylbetaine (FTAB), was investigated over 109 d with aerobic wastewater-treatment plant (WWTP) sludge. Results show that biodegradation of 6:2 FTAA and 6:2 FTAB produces 6:2 fluorotelomer alcohol (FTOH), 6:2 fluorotelomer carboxylic acid (FTCA), 6:2 fluorotelomer unsaturated carboxylic acid (FTUCA), 5:3 FTCA, and short-chain perfluoroalkyl carboxylates (PFCAs). Additional degradation products included 6:2 fluorotelomer sulfonamide (FTSAm), which was a major degradation product in the presence of either active or sterilized sludge, whereas 6:2 fluorotelomer sulfonate (FTSA) production was measured with sterilized sludge only. Six additional degradation products were tentatively identified by quadrupole time-of-flight mass spectrometry (qTOF-MS) and attributed to N-dealkylation and oxidation of 6:2 FTAA. Environ Toxicol Chem 2017;36:2012-2021. © 2017 SETAC.

Iodine/TBHP‐Promoted One‐Pot Deoxygenation and Direct 2‐Sulfonylation of Quinoline N‐Oxides with Sodium Sulfinates: Facile and Regioselective Synthesis of 2‐Sulfonylquinolines

A highly efficient iodine/TBHP‐mediated one‐pot deoxygenative and regioselective 2‐sulfonylation of quinoline N‐oxides with sodium sulfinate salts has been developed. This metal‐, base‐, and phosphorus‐free protocol employs readily accessible and easy‐to‐handle reagents and can be conveniently carried out at room temperature under mild conditions, providing an alternative access to a series of 2‐sulfonylquinolines and other related heteroaryl sulfone products in moderate‐to‐excellent yields within a short reaction time.

Electrochemical behavior of 2-aminodiphenylamine and efficient factors on the site-selectivity of sulfonylation reaction: Experimental and theoretical studies

The electrochemical dimerization of 2-aminodiphenylamine (2ADPA) has been studied. The data indicate that electrochemically generated (Z)-N-(6-iminocyclohexa-2,4-dien-1-ylidene) aniline (2ADPAox) can serve as a Michael acceptor in the reaction with starting molecular (2ADPA) form and converts to the corresponding dimer. The mechanism of dimerization has been studied using both controlled-potential coulometry and cyclic voltammetry. The anodic dimerization of 2-aminodiphenylamine has been successfully performed under constant current condition in good yield and purity in an undivided cell. Furthermore, electrochemical oxidation of 2ADPA has been studied both experimentally and theoretically to provide insight into the influence of some factors on the type of chemical reaction which follows 2ADPAox. The effect of natural charge of 2ADPAox on the reaction site was calculated using PBE/def2-SVP level of theory to identify regioselective sulfonation of 2ADPA. The results indicate that the natural charge of Michael acceptor 2ADPAox and thermodynamic stability of products lead to site-selectivity sulfonylation of 2ADPA. In addition, the sulfone products were evaluated for their in vitro antibacterial activity against two bacterial ATCC strains (Staphylococcus aureus, and Escherichia coli).

COMPOSITE OF CHITOSAN VANILIN / SULFONATED POLYSTYRENE AS POLYMER ELECTROLYTE MEMBRANES : CATIONIC EXCHANGE CAPACITY, SWELLING DEGREE AND THERMAL PROPERTIES

Research on the preparation and characterization of sulfonated polystyrene (PST) /chitosan vanillin (KV) composite as electrolyte membranes has been conducted in order to investigate the effect of PST and KV composition to its chemical and physical properties. Polystyrene was modified by sulfonation reaction to produces PST<strong>, </strong>meanwhile chitosan was modified by schift base reaction to produces KV. The composite membranes were prepared by casting method and were characterized in order to identify the functional groups contained in the composite, the cation exchange capacity (CEC), the Swelling Degree (SD), the thermal properties and the morphology. The peak of imine vibration in the FTIR spectrum indicates that the chitosan vanilin was succesfully synthesized. Meanwhile, the peak of sulfonate vibration indicates the product of sulfonation on polystyrene. The result of CEC analysis shows that the addition of sulfonate groups on polystyrene and the addition of phenolic groups on chitosan increase the CEC value. The increasing of PST and KV concentration in membrane enhance the CEC value. However, the increasing of PST concentration in membrane composition even decrease the Swelling Degree of membranes. Meanwhile, the increasing of KV concentration increase the swelling degree of membranes. Thermal analysis shows that the thermal decomposition of membranes occurs in three stages i.e. the dehydration of water molecules, the degradation of the subtituen groups and the plasticizer and the degradation of the back bone of chitosan and polystyrene.

COMPOSITE OF CHITOSAN VANILIN / SULFONATED POLYSTYRENE AS POLYMER ELECTROLYTE MEMBRANES : CATIONIC EXCHANGE CAPACITY, SWELLING DEGREE AND THERMAL PROPERTIES

Research on the preparation and characterization of sulfonated polystyrene (PST) /chitosan vanillin (KV) composite as electrolyte membranes has been conducted in order to investigate the effect of PST and KV composition to its chemical and physical properties. Polystyrene was modified by sulfonation reaction to produces PST<strong>, </strong>meanwhile chitosan was modified by schift base reaction to produces KV. The composite membranes were prepared by casting method and were characterized in order to identify the functional groups contained in the composite, the cation exchange capacity (CEC), the Swelling Degree (SD), the thermal properties and the morphology. The peak of imine vibration in the FTIR spectrum indicates that the chitosan vanilin was succesfully synthesized. Meanwhile, the peak of sulfonate vibration indicates the product of sulfonation on polystyrene. The result of CEC analysis shows that the addition of sulfonate groups on polystyrene and the addition of phenolic groups on chitosan increase the CEC value. The increasing of PST and KV concentration in membrane enhance the CEC value. However, the increasing of PST concentration in membrane composition even decrease the Swelling Degree of membranes. Meanwhile, the increasing of KV concentration increase the swelling degree of membranes. Thermal analysis shows that the thermal decomposition of membranes occurs in three stages i.e. the dehydration of water molecules, the degradation of the subtituen groups and the plasticizer and the degradation of the back bone of chitosan and polystyrene.

Copper‐Catalyzed Hydrosulfonylation of Alkynes Employing Sulfonohydrazides toward the Synthesis of Vinyl Sulfones

AbstractThe hydrosulfonylation of terminal alkynes employing sulfonohydrazides has been accomplished with copper‐catalysis in the presence of BPO (benzoic peroxyanhydride). Generally, excellent yield of the vinyl sulfone products has been acquired by heating the reaction at 70°C in DMSO.

Cholesterol Sulfonation Enzyme, SULT2B1b, Modulates AR and Cell Growth Properties in Prostate Cancer.

Cholesterol accumulates in prostate lesions and has been linked to prostate cancer incidence and progression. However, how accumulated cholesterol contributes to prostate cancer development and progression is not completely understood. Cholesterol sulfate (CS), the primary sulfonation product of cholesterol sulfotransferase (SULT2B1b), accumulates in human prostate adenocarcinoma and precancerous prostatic intraepithelial neoplasia (PIN) lesions compared with normal regions of the same tissue sample. Given the enhanced accumulation of CS in these lesions, it was hypothesized that SULT2B1b-mediated production of CS provides a growth advantage to these cells. To address this, prostate cancer cells with RNAi-mediated knockdown (KD) of SULT2B1b were used to assess the impact on cell growth and survival. SULT2B1b is expressed and functional in a variety of prostate cells, and the data demonstrate that SULT2B1b KD, in LNCaP and other androgen-responsive (VCaP and C4-2) cells, results in decreased cell growth/viability and induces cell death. SULT2B1b KD also decreases androgen receptor (AR) activity and expression at mRNA and protein levels. While AR overexpression has no impact on SULT2B1b KD-mediated cell death, the addition of exogenous androgen is able to partially rescue the growth inhibition induced by SULT2B1b KD in LNCaP cells. These results suggest that SULT2B1b positively regulates the AR either through alterations in ligand availability or by interaction with critical coregulators that influence AR activity. These findings provide evidence that SULT2B1b is a novel regulator of AR activity and cell growth in prostate cancer and should be further investigated for therapeutic potential. Mol Cancer Res; 14(9); 776-86. ©2016 AACR.

Optimization of conditions for synthesizing sulfonated hydrazides of benzoic and benzenesulfonic acids

The kinetic relationships of arenesulfonation of benzoic and benzenesulfonic acid hydrazides were studied. Based on the data obtained, the conditions for synthesizing these products were optimized. The synthesis can be performed using aqueous-organic solvents containing 2-propanol, 1,4-dioxane, or tetrahydrofuran as nonaqueous component. The thermal stability of benzenesulfohydrazide and its sulfonation product was compared on the basis of data of gas chromatography–mass spectrometry. The fragmentation pathways of the reactants and target product, sulfonated benzenesulfohydrazide, were suggested.

Oxidation of cefazolin by potassium permanganate: Transformation products and plausible pathways

Cefazolin was demonstrated to exert high reactivity toward permanganate (Mn(VII)), a common oxidant in water pre-oxidation treatment. In this study, five transformation products were found to be classified into three categories according to the contained characteristic functional groups: three (di-)sulfoxide products, one sulfone product and one di-ketone product. Products analyses showed that two kinds of reactions including oxidation of thioether and the cleavage of unsaturated CC double bond occurred during transformation of cefazolin by Mn(VII). Subsequently, the plausible transformation pathways under different pH conditions were proposed based on the identified products and chemical reaction principles. More importantly, the simulation with real surface water matrix indicated that the proposed transformation pathways of cefazolin could be replayed in real water treatment practices.

Kinetics and Mechanism of Oxidation of d-Penicillamine in Acidified Bromate and Aqueous Bromine

The oxidation of the biologically active compound d-penicillamine (Depen) by acidic bromate has been studied. The stoichiometry of the reaction is strictly 1 : 1, in which Depen is oxidized only as far as the sulfonic acid with no cleavage of the C–S bond to yield sulfate. Electrospray ionization spectroscopy shows that Depen is oxidized through addition of oxygen atoms on the sulfur centre to successively yield sulfenic and sulfinic acids before the product sulfonic acid. In conditions of excess Depen over the oxidant, sulfenic acid was not observed. Instead, nearly quantitative formation of the dimer was obtained. The dimer, which is the d-penicillamine disulfide species, was formed from a reaction of the putative highly electrophilic sulfenic acid with unreacted Depen in a condensation-type reaction and not through a radical-mediated pathway. Further oxidation of the dimer is slow because it is the most stable intermediate in the oxidation of Depen. In excess oxidant conditions, negligible dimer formation is observed. The reaction of bromine with Depen gives a stoichiometry of 3 : 1 with the same sulfonic acid product. This reaction is so fast that it is essentially diffusion controlled. Our stopped-flow instrument could not capture the oxidation by the first 2 moles of bromine, only the section of the reaction in which the sulfinic acid is oxidized to sulfonic acid.

Selective Photooxidation of a Mustard‐Gas Simulant Catalyzed by a Porphyrinic Metal–Organic Framework

AbstractThe photooxidation of a mustard‐gas simulant, 2‐chloroethyl ethyl sulfide (CEES), is studied using a porphyrin‐based metal–organic framework (MOF) catalyst. At room temperature and neutral pH value, singlet oxygen is generated by PCN‐222/MOF‐545 using an inexpensive and commercially available light‐emitting diode. The singlet oxygen produced by PCN‐222/MOF‐545 selectively oxidizes CEES to the comparatively nontoxic product 2‐chloroethyl ethyl sulfoxide (CEESO) without formation of the highly toxic sulfone product. In comparison to current methods, which utilize hydrogen peroxide as an oxidizing agent, this is a more realistic, convenient, and effective method for mustard‐gas detoxification.

Selective Photooxidation of a Mustard-Gas Simulant Catalyzed by a Porphyrinic Metal-Organic Framework.

The photooxidation of a mustard-gas simulant, 2-chloroethyl ethyl sulfide (CEES), is studied using a porphyrin-based metal-organic framework (MOF) catalyst. At room temperature and neutral pH value, singlet oxygen is generated by PCN-222/MOF-545 using an inexpensive and commercially available light-emitting diode. The singlet oxygen produced by PCN-222/MOF-545 selectively oxidizes CEES to the comparatively nontoxic product 2-chloroethyl ethyl sulfoxide (CEESO) without formation of the highly toxic sulfone product. In comparison to current methods, which utilize hydrogen peroxide as an oxidizing agent, this is a more realistic, convenient, and effective method for mustard-gas detoxification.

Occurrence and ecological risks from fipronil in aquatic environments located within residential landscapes

This study investigated the occurrence of fipronil and its metabolites in aquatic environments in residentially-developed landscapes, including five canals and three retention ponds. Fipronil was detected at four of the sites, with concentrations of 0.5–207.3ngL−1. Fipronil sulfone and fipronil sulfide were detected at three sampling sites, with concentrations ranging from 0.46 to 57.75 and 0.40–26.92ngL−1, respectively. Multiple risk assessment methods were performed to characterize potential ecological risks, including deterministic screening and probabilistic risk assessment techniques. The deterministic method indicated no risk to certain biotic groups (i.e. aquatic plants, fish, molluscs, and algae–moss–fungi), but did indicate risks to larval insects and crustaceans. Results from the probabilistic risk assessment indicated significant ecological risks (acute and chronic) ranging from 0.75 to 58.9% and 3.9–35.0% when organisms were exposed to the maximum and median concentrations detected, respectively. The potentially affected fraction of species (PAF) likely to be acutely impacted ranged from 4.6 to 8.1% (fipronil), 0.2–1.6% (fipronil sulfone), and 1.9–3.1% (fipronil sulfide) in the ponds with frequent detectable concentrations. The PAF likely to be impacted at chronic toxicity levels ranged from 16.5 to 23.8% for fipronil. Joint probability curve analysis indicated that concentrations exceeded the LC50 of the most sensitive 5% of species 8.5–18.8% of the time at two of the sites with the most frequent detections. Using the more conservative NOEC/LOEC values, there was a 75–78% probability that concentrations were high enough to negatively affect the most sensitive 5% of species at the same two sites, indicating significant risks for chronic toxicity. JPCs indicated a ≤2.6% probability of fipronil sulfone exceeding the LC50 concentrations for the most sensitive 5% of species at the same two sites; and a 4.3–6.8% probability of fipronil sulfide exceeding the LC50 concentrations at the same sites. Results indicate that fipronil and its sulfone and sulfide degradation products may present significant risks to aquatic organisms in some residentially-developed areas.