Substituted Diphenylamine Antioxidants and Benzotriazole UV Stabilizers in Aquatic Organisms in the Great Lakes of North America: Terrestrial Exposure and Biodilution.

Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are industrial additives of emerging environmental concern. However, the bioaccumulation, biomagnification, and spatial distribution of these contaminants in the Great Lakes of North America are unknown. The present study addresses these knowledge gaps by reporting SDPAs and BZT-UVs in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), and their food web in the Great Lakes for the first time. Herring gull eggs showed much higher detection frequency and concentrations of target SDPAs and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) than that of the whole body fish homogenate. For herring gull eggs, the samples from upper Great Lakes contained significantly greater levels of SDPAs than those eggs from lower lakes, possibly due to the differences in terrestrial food in diet. Interestingly, the predominant SDPAs in herring gull eggs were dinonyl- (C9C9) and monononyl-diphenylamine (C9) which were previously shown to be less bioaccumulative than other SDPAs in fish. In contrast, dioctyl-diphenylamine (C8C8) was the major SDPA in lake trout, and biodilution of C8C8 was observed in a Lake Superior lake trout food web. Such variations in herring gull eggs and fish indicate the differences in accumulation and elimination pathways of SDPAs and BZT-UVs and require further elucidation of these mechanisms.

Distribution, Partitioning and Bioaccumulation of Substituted Diphenylamine Antioxidants and Benzotriazole UV Stabilizers in an Urban Creek in Canada.

Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs), previously under reported classes of organic contaminants, were determined in sediment, water, and freshwater biota in an urban creek in Canada. SDPAs and BZT-UVs were frequently detected in all matrices including upstream of the urban area in a rural agricultural/woodlot region, suggesting a ubiquitous presence and bioaccumulation of these emerging contaminants. Spatial comparisons were characterized by higher levels of SDPAs downstream compared with the upstream, implying a possible influence of the urban activities on the antioxidant contamination in the sampling area. In sediment, 4,4'-bis(α,α-dimethylbenzyl)-diphenylamine (diAMS), dioctyl-diphenylamine (C8C8), and dinonyl-diphenylamine (C9C9) were the most dominant congeners of SDPAs, with concentrations up to 191 ng/g (dry weight, d.w.). Benthic invertebrates Crayfish (Orcoescties spp.) had larger body burdens of SDPAs and BZT-UVs compared to pelagic fish (hornyhead chub (Nocomis biguttatus) and common shiner (Luxilus cornutus)) in the creek and partitioning coefficients demonstrated that sediment was the major reservoir of these contaminants. This is the first report of bioaccumulation and partitioning behaviors of SDPAs and BZT-UVs in freshwater environments.

Determination of beta-blockers and beta2-agonists in sewage by solid-phase extraction and liquid chromatography-tandem mass spectrometry.

A method using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of 12 beta-blockers and beta(2)-agonists in wastewater samples. Extraction of the drugs was effected by an Oasis MCX cartridge with a strong cation resin adsorbent. Matrix coextractives were removed from the SPE cartridge by methanol prior to the elution of the drugs with a mixture of dichloromethane, 2-propranol, and ammonium hydroxide. The extract was analyzed by LC-MS/MS with electrospray ionization operating in the positive mode. Recovery of the 12 compounds was in most cases better than 85% at the fortification levels of 500 and 50 ng/L, with standard deviations between 3 and 7%. Based on a concentration factor of 250, the method detection limits ranged from 6 to 11 ng/L for the target compounds. No degradation of these drugs in spiked sewage effluent samples was observed over a storage period of 7 days at 4 degrees C in the dark. Many beta-blockers were detected in the 14 wastewater samples collected from seven Canadian sewage treatment plants; those occurring at the highest concentrations were atenolol, acebutolol, sotalol, and metroprolol, with overall median concentrations of 1370, 339, 282, and 257 ng/L, respectively. However, there was only a small decrease in the median concentrations of these beta-blockers between the primary and final effluent, suggesting that these drugs are not easily removed by the sewage treatment processes. As a result of selective extraction and effective removal of coextractives, no matrix effect was observed for the samples during LC-MS/MS analyses.

Determination of ofloxacin, norfloxacin, and ciprofloxacin in sewage by selective solid-phase extraction, liquid chromatography with fluorescence detection, and liquid chromatography--tandem mass spectrometry.

A solid-phase extraction (SPE) and liquid chromatographic (LC) method was developed for the determination of selected fluoroquinolone (FQ) drugs including ofloxacin, norfloxacin, and ciprofloxacin in municipal wastewater samples. Extraction of the FQs was carried out with a weak cation exchanger SPE cartridge, the Oasis WCX. The cartridge was washed with water and methanol as a cleanup before the FQs were eluted by a mixture of methanol, acetonitrile, and formic acid. Separation of the FQs was achieved by using a Zorbax SB-C8 column under isocratic condition at a flow rate of 0.2mL/min. Recoveries of the FQs in spiked final effluent samples were between 87 and 94% with a relative standard deviation of less than 6%. Several techniques have been evaluated for the detection of FQs in sewage extracts; they included fluorescence detection and electrospray ionization (ESI) mass spectrometry using either mass-selective detection or tandem mass spectrometry (MS/MS). When they were applied to sewage influent and effluent samples, the LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode proved to be best suited for the determination of FQs in sewage samples as it provided the highest sensitivity (limit of quantification 5ng/L) and selectivity. The observation of signal suppression (matrix effect) for some FQs in ESI LC-MS and LC-MS/MS is discussed and a solution is proposed. The three FQs were detected in all the sewage samples tested in this work, with median concentrations between 34 and 251ng/L.

Occurrence and fate of substituted diphenylamine antioxidants and benzotriazole UV stabilizers in various Canadian wastewater treatment processes.

Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are additives used in industrial and consumer products to prevent degradation or color change of materials, but their environmental fate and disposition are not well characterized. In this study, SDPAs and BZT-UVs were analyzed in 68 liquid and 39 solid samples collected from 9 wastewater treatment plants (WWTPs) in Canada to investigate the occurrence and fate of these contaminants. The median concentrations of ΣSDPAs and ΣBZT-UVs was 483 and 76.2 ng L-1 in influent, 28.4 and 4.84 ng L-1 in effluent, and 2750 and 457 ng g-1 in biosolids (dry weight), respectively. Dinonyl-diphenylamine (C9C9) was the predominant congener of SDPAs in all matrices (>40%). For target BZT-UVs, the major components were 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (UV234) and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328). SDPAs and BZT-UVs were effectively removed (>90%) from the liquid stream in most WWTPs mainly through sludge sorption and separation, but biotransformation, UV treatment and filtration may also contribute to removal of some contaminants in advanced treatment plants. In contrast, the removal efficiency of target contaminants using chemically assisted primary treatment was low, likely due to the short hydraulic retention time of this site. Our results suggest that wastewater effluent is a vector of SDPAs and BZT-UVs to the aquatic environment. The results also highlight the high concentrations of SDPAs and BZT-UVs associated with the solid stream in WWTPs, which could affect the beneficial use of biosolids (e.g., compost or land applications).

Simultaneous determination of substituted diphenylamine antioxidants and benzotriazole ultra violet stabilizers in blood plasma and fish homogenates by ultra high performance liquid chromatography-electrospray tandem mass spectrometry.

Analytical methods were developed for the determination of eight substituted diphenylamines (SDPAs) and six benzotriazole UV stabilizers (BZT-UVs) in blood plasma and fish homogenate matrices. Liquid-liquid extraction by methyl tert-butyl ether and denaturation by KOH following silica gel packed column clean-up was employed for blood plasma preparation. For the fish homogenate samples, ultrasonic assisted solvent extraction combined with automated gel permeation chromatography and silica gel packed column clean-up was used. The target compounds were determined by optimized ultra performance liquid chromatography-tandem mass spectrometry in positive electrospray ionization mode. The method limits of quantification (MLOQs) of the 14 analytes ranged from 0.002 to 1.5ngg(-1) and 0.001 to 2.3ngg(-1) (wet weight, w.w.) for blood plasma and fish homogenate, respectively. The total recoveries of the target compounds varied from 61% to 100% (mean 77±9%). Eleven targets including monobutyl- (C4), dibutyl- (C4C4), monooctyl- (C8), monobutyl monooctyl- (C4C8), dioctyl-(C8C8), monononyl- (C9), dinonly-(C9C9) and 4,4'-bis(α,α-dimethylbenzyl)-(diAMS) DPAs, as well as 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (UV234), 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl) phenol (UV327) and 2-(2H-Benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) were identified in the environmental biota samples, with concentrations in the range of

Determination of endocrine-disrupting phenols, acidic pharmaceuticals, and personal-care products in sewage by solid-phase extraction and gas chromatography-mass spectrometry.

The occurrence, fate, and effects of phenols with endocrine-disrupting properties as well as some pharmaceuticals and personal-care products in the environment have frequently been discussed in recent literature. In many cases, these compounds were determined by using individual methods which can be time-consuming if results for multiple parameters are required. Using a solid-phase extraction procedure with an anion exchanger in this work, we have developed and optimized a multi-residue method for the extraction of 21 phenols and acids in sewage influent and effluent. The phenols and acids were then selectively eluted in separate fractions and were converted into pentafluoropropionyl (PFP) and tert-butyldimethylsilyl (TBDMS) derivatives, respectively, for gas chromatography-mass spectrometric (GC/MS) determination. When applied to the sewage samples under study, the results for nonylphenol, bisphenol A (BPA), triclosan (TCS), 17ss-estradiol (E2), estrone (E1), salicylic acid, ibuprofen, naproxen, diclofenac, and a few other acidic drugs were consistent with those determined previously by individual methods. Using the same procedure, we also report, for the first time, the occurrence of 2-phenylphenol and parabens in those sewage samples.

Selected chloro and bromo derivatives of triclosan--syntheses and their occurrence in Canadian sewage and biosolid samples.

The occurrence of triclosan (TCS), a general purpose antibacterial agent contained in numerous consumer and personal-care products, in the aquatic environment is well known. To a lesser degree, the formation of chlorinated and brominated derivatives of TCS during the chlorination of the antibacterial has also been reported. Presumably due to the lack of authentic standards, very few reports have been published on the levels of these halogenated TCSs in the environment. For this purpose, we have synthesized six selected halogenated derivatives of TCS, namely, 3-Cl-, 5-Cl-, 3,5-Cl2-, 3-Br-, 5-Br-, and 3,5-Br2- TCSs, with supporting (1)H-NMR (nuclear magnetic resonance) and GC-MS (gas chromatography-mass spectrometry) data for their structural assignments. Using these model compounds together with sensitive analytical methods, we were able to identify and quantify the above compounds together with their precursor compound TCS in Canadian municipal wastewater and biosolid samples for the first time. While detected in all influent (range from 1.4 to 24.1 ng L(-1)) and biosolid (range from 7.7 to 274 ng g(-1)) samples, the concentrations of these chlorinated TCS were generally from 100- to 1,000-fold lower than TCS in the same sample. Even lower levels (<20 ng/g in 85% of the results) of brominated TCS were found in biosolids, and they were mostly undetected in sewage.

Occurrence and fate of rosuvastatin, rosuvastatin lactone, and atorvastatin in Canadian sewage and surface water samples.

Rosuvastatin (RST) and atorvastatin (ATO) are prescription drugs and members in the statin family used for the treatment of elevated cholesterol levels. A method using solid-phase extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of ATO, RST and its metabolite rosuvastatin lactone (RSTL) in sewage and surface water samples has been developed. In the influent and effluent samples collected from 11 sewage treatment plants located in Ontario, Canada, ATO, RST, and RSTL were detected in all samples with median concentrations of 166 ng L(-1) (influent) and 77 ng L(-1) (effluent) for ATO, 448 ng L(-1) (influent) and 324 ng L(-1) (effluent) for RST, as well as 158 ng L(-1) (influent) and 41 ng L(-1) (effluent) for RSTL. Due to the inter-conversion between RST and RSTL, the total concentration of RST and RSTL in a sewage sample should be reported. The median removal rate by wastewater treatment was 66% for ATO and 22% for RST and RSTL combined. These statins were quite persistent in sewage. After a storage period of 21 and 62 days, there was only a slight decrease in ATO concentration and no change in the total RST concentrations. These three compounds were also detected in a number of surface water samples at low ng L(-1) concentrations. This is the first reported occurrence and fate of RST and RSTL in the Canadian aquatic environment.