Development and validation of LC-MS/MS method for trace analysis of acrylamide, acrylic acid and N, N-methylene bis acrylamide in sandy loam soil.

Acrylamide and N, N-methylene bis acrylamide are most commonly used monomer and crosslinker compounds employed in synthesis of super absorbent hydrogels. When applied as soil conditioners, there are apprehensions that these hydrogels degrade over time and thus may release the toxic monomers in the soil. A method was thus developed using Liquid Chromatography tandem mass spectrometry (LC-MS/MS) for the trace level quantification of acrylamide (AD), acrylic acid (AA) and N,N-methylene-bis-acrylamide (MBA) in sandy loam soil amended by two test hydrogels the Pusa Hydrogel and SPG 1118 hydrogel prepared using AD and MBA. The MRM (multiple reaction monitoring) transitions were optimized for both the compounds. Soil samples were extracted using dispersive solid-phase extraction (dSPE) with a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) technique, employing acetonitrile. All analytes were quantified at trace levels within a five-minute run using UHPLC equipped with a C-18 column. Single laboratory validation of the developed method in soil matrix was conducted based on specificity, linearity, sensitivity, accuracy, precision, matrix effect and measurement of uncertainty. LC-MS/MS exhibited a linear response in the concentration range of 0.001 to 1 µg mL-1, with correlation coefficient >+0.99. Acceptable recovery (within 70-120 %) with repeatability (%RSD ≤20 %) was obtained at 0.01 to 1 µg g-1 fortification levels. LOQ (Limit of quantification) of the method for AD, AA and MBA in soil matrix were 0.05, 1 and 0.01 µg g-1, respectively. Both intra-laboratory repeatability and intermediate precision at LOQ suggested well acceptable precise (HorRat≈ 0.3) method for quantification. Matrix enhancement effect was observed in the order: AA>AD>MBA. The Expanded Uncertainty (EU) in soil matrix at LOQ was 21.64 %, 28 % and 19 % for AD, AA and MBA respectively. Groundnut and wheat grown with application of the hydrogels showed no detectable residues of monomers in soil samples (total n = 60) near the root zone at the time of crop harvesting.

Competitive and noncompetitive fluorescence polarization immunoassays for the detection of benzothiostrobin using FITC-labeled dendrimer-like peptides.

Peptides obtained from phage display libraries are valuable reagents for small-molecule immunoassays. However, their application in fluorescence polarization immunoassays (FPIAs) is limited by phage particles. Here, monomer, dendrimer-like dimer, tetramer peptidomimetic and anti-immunocomplex tracers were designed and synthesized using lysine as special scaffolds and spacers to develop competitive and noncompetitive FPIAs for benzothiostrobin. The affinity between tracers and monoclonal antibodies or immunocomplexes increased with the tracer valence. A higher signal-to-noise ratio and sensitivity could be generated in the FPIAs based on tetramer tracers. The sensitivities of competitive (50% inhibitory concentration) and noncompetitive (50% saturation concentration) FPIAs were 19.71 ± 4.65 and 40.43 ± 2.73 ng mL-1, respectively. The spiked recoveries were 78.3%-105.2% with relative standard deviations (RSDs) of 0.7%-15.4% for the competitive FPIA, while 78.7%-115.3% with RSDs of 0.7%-12.5% for the noncompetitive FPIA. The amounts of benzothiostrobin in rice detected by the FPIAs were consistent with those detected by high performance liquid chromatography.

Environmental risk assessment of polycarboxylate polymers used in cleaning products in the United States.

Polycarboxylate polymers have been common components of consumer and institutional cleaning products for decades. With interest heightened in the potential environmental impact of polymers, the American Cleaning Institute, the industry trade association of the cleaning products industry in the United States, is reassessing the state of the science regarding the environmental safety of polymers in cleaning products. In this case study, acrylic acid homopolymers and acrylic acid-maleic acid copolymers are evaluated using historical ecotoxicity data that have been reported over the past three decades. The evaluation includes an environmental exposure assessment that is based on recent information regarding the occurrence of those ingredients in cleaning products and market sales data for cleaning products sold in the United States. The ecotoxicity of polycarboxylate polymers is generally low. Consequently, the potential environmental risks associated with their use in cleaning products in the United States are low even when applying very conservative assumptions to the environmental exposure assessment. In addition, there are recent supporting conclusions from assessments by the governments of Australia and Canada that polycarboxylate polymers are polymers of low concern, and the U.S. Environmental Protection Agency has included a number of polycarboxylate polymers among the ingredients on its Safer Chemical Ingredients List based on their low hazard profile.

Evaluation of pyraoxystrobin bioconcentration in zebrafish (Danio rerio) using modified QuEChERS extraction.

Pyraoxystrobin is a novel strobilurin fungicide that is widely used on many crops. The high log Kow of pyraoxystrobin implies that it tends to accumulate in aquatic organisms. This study optimized the sorbents of QuEChERS (quick, easy, cheap, effective, rugged, and safe) using 13C-labelled pyraoxystrobin as the internal standard (IS). It has been established a QuEChERS-LC-MS/MS IS method to study the bioconcentration and elimination of pyraoxystrobin in zebrafish (Danio rerio). The results indicated that the method had satisfactory linearity between 0.234 and 15 µg L-1 (R2 = 0.9996). The limits of detection (LOD) and quantification (LOQ) for pyraoxystrobin were 0.01 and 0.03 µg L-1, respectively. The LOQs of the method for water and zebrafish were 0.05 µg L-1 and 0.01 mg/kg, respectively. The mean recovery of pyraoxystrobin in zebrafish and water at fortification levels of 0.01-0.3 mg kg-1 and 0.05-1.5 µg L-1 ranged from 98.31 to 105.61% and 101.87 to 108.48%, respectively, with a % RSD (relative standard deviation) of 0.94-3.57%. The bioconcentration has been evaluated. The bioconcentration factors for pyraoxystrobin in zebrafish were 1,792 and 3,505 after exposure to 0.5 µg L-1 for 168 h and 0.05 µg L-1 for 216 h, respectively. The half-life of pyraoxystrobin in zebrafish was 9.0-9.5 d.

HPLC method transfer study for simultaneous determination of seven angiotensin II receptor blockers.

In this study, a sensitive high-performance liquid chromatography method was developed and validated for the simultaneous determination of seven angiotensin II receptor blockers, namely, hydrochlorothiazide, chlorthalidone, eprosartan mesylate, valsartan, losartan potassium, irbesartan, and candesartan cilexetil. Different chromatographic parameters were tested and fully optimized. Best chromatographic separation was accomplished on a reversed-phase octadecylsilyl column (250 × 4.6 mm id; 5 µm) under gradient elution using methanol/sodium phosphate monobasic buffer (0.01 M, pH 6.5) as mobile phase. The detection of target analytes was obtained at 254 nm. The pH of the buffer has been selected according to Marvin® sketch software. The proposed method was validated according to ICH guidelines and showed good precision (relative standard deviation < 1), good linearity (square of correlation coefficient ≥ 0.999), and high accuracy (between 98 and 102%) with detection limit and quantitation limit (40 and 160 ng/mL, respectively) for all the detected analytes.

Evaluation of Isobornyl Acrylate Content in Medical Devices for Diabetes Treatment.

Background: Along with increased usage of continuous glucose monitors, flash glucose monitors, and patch pumps by patients with diabetes, the frequency of skin reactions has also increased. Skin irritation and itching can be annoying to users. However, more serious contact allergies to one or more components of the adhesives or plastic material of the housing of the devices can become lifelong. Redness and itchiness are so strong that patients can no longer use a particular system. In August 2017, a major culprit allergen, isobornyl acrylate (IBOA), was identified for these more serious reactions. Objectives: Our objective was to evaluate IBOA content in different medical products. Methods: The plastic material used for the housing of the Freestyle Libre (n = 3), Dexcom G6 (n = 3), and Enlite (n = 4) was analyzed for IBOA content by gas chromatography-mass spectrometry. Adhesives of the different systems were also analyzed. Results: IBOA was found in the housings of Freestyle Libre and Enlite sensor, but not in the Dexcom G6. Conclusions: Patients with an IBOA allergy should consider switching to a medical product without IBOA. Furthermore, removal of IBOA from devices that contact the skin is encouraged.

[Simultaneous determination of four kinds methyl acrylate compounds in workplace air].

Objective: To develop a solvent desorption-gas chromatography method for simultaneous determination of methyl methacrylate (MMA) , ethyl methacrylate (EMA) , n-propyl methacrylate (PMA) and butyl methacrylate (BMA) in workplace air. Methods: MMA, EMA, PMA and BMA in workplace air were captured by charcoal tubes and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of MMA, EMA, PMA and BMA were 0-8 305.00 mg/L, 0-9 080.50 mg/L, 0-8 899.00 mg/L and 0-8 371.00 mg/L respectively, and the related coefficients were between 0.999 96-0.999 98. The relative standard deviations (RSD) within the group were 0.56%-1.71%, 0.45%-1.65%, 0.51%-1.49% and 0.45%-1.50% respectively, and the RSD between the group were 1.14%-2.79%, 0.79%-2.13%, 0.93%-2.30% and 1.09%-2.84% respectively. The average desorption efficiencies were 95.76%-99.58%, 97.82%-102.28%, 98.55%-102.28%and 98.70%-102.40% respectively. The minimum quantification concentrations were 0.12 mg/m(3), 0.10 mg/m(3), 0.07 mg/m(3) and 0.07 mg/m(3) respectively (3.00 L sample) . The samples could be stored at room temperature for at least 7 days. Conclusion: This method could be used for monitoring of MMA, EMA, PMA and BMA in workplace air.

Determination of adhesive acrylates in recycled polyethylene terephthalate by fabric phase sorptive extraction coupled to ultra performance liquid chromatography - mass spectrometry.

This article presents fabric phase sorptive extraction (FPSE) as a simple and effective pre-concentration method for the enrichment of acrylate compounds in different food simulants and subsequent analysis of the extracts by ultra-high-performance liquid chromatography with mass spectrometric detection (UPLC-MS). Acrylate compounds come from acrylic adhesives used commonly for sticking the paper labels on polyethylene terephthalate (PET) bottles and therefore, they may exist in recycled polyethylene terephthalate (rPET). Four acrylates were studied: ethylene glycol dimethacrylate (EGDM), pentaerythritol triacrylate (PETA), triethylene glycol diacrylate (TEGDA) and trimethylolpropane triacrylate (TMPTA). Five different types of FPSE media coated with different sol-gel sorbents were studied and finally sol-gel polyethylene glycol- polypropylene glycol-polyethylene glycol triblock copolymer (PEG-PPG-PEG) coated FPSE media was chosen for its satisfactory results. The optimal conditions affecting the extraction efficiency of compounds were determined in three different food simulants. Statistical evaluation of this method reveals good linearity and precision. Under the optimized conditions, the method provided limits of detection of the compounds in the range of (0.1-1.9 ng g-1, 0.1-1.2 ng g-1, 0.2-2.3 ng g-1) in EtOH 10%, HAc 3% and EtOH 20% and the enrichment factor values (EFs) after applying N2 were in the range of 11.1-25.0, 13.8-26.3, 8.3-21.9, in simulants A, B and C respectively. The optimized method was applied successfully to analyze thirteen types of recycled PET samples. Acrylates were found in some of the samples at ng g-1 levels.

Environmental risks associated with contaminants of legacy and emerging concern at European aquaculture areas.

The contamination of marine ecosystems by contaminants of emerging concern such as personal care products or per- and polyfluoroalkyl substances is of increasing concern. This work assessed the concentrations of selected contaminants of emerging concern in water and sediment of European aquaculture areas, to evaluate their co-variation with legacy contaminants (polycyclic aromatic hydrocarbons) and faecal biomarkers, and estimate the risks associated with their occurrence. The 9 study sites were selected in 7 European countries to be representative of the aquaculture activities of their region: 4 sites in the Atlantic Ocean and 5 in the Mediterranean Sea. Musks, UV filters, preservatives, per- and polyfluoroalkyl substances and polycyclic aromatic hydrocarbons were detected in at least one of the sites with regional differences. While personal care products appear to be the main component of the water contamination, polycyclic aromatic hydrocarbons were mostly found in sediments. As expected, generally higher levels of personal care products were found in sewage impacted sites, urbanised coasts and estuaries. The risk assessment for water and sediment revealed a potential risk for the local aquatic environment from contaminants of both legacy and emerging concern, with a significant contribution of the UV filter octocrylene. Despite marginal contributions of per- and polyfluoroalkyl substances to the total concentrations, PFOS (perfluorooctane sulfonate) aqueous concentrations combined to its low ecotoxicity thresholds produced significant hazard quotients indicating a potential risk to the ecosystems.

Electrochemical simultaneous analysis of dopamine and epinephrine using double imprinted One MoNomer acryloylated graphene oxide-carbon black composite polymer.

A novel One MoNomer dual imprinted graphene oxide/carbon black composite polymer was developed applying 'surface-grafting from' approach on the screen printed carbon electrode for the electrochemical sensing of dopamine and epinephrine. Acryloylated-graphene oxide/carbon black was synthesized for the first time. This served both as a crosslinker and monomer leading to the fast electron transfer from the redox centre to the electrode. The oxidation peak potentials of both the targets were found separated by 200 mV which enabled their simultaneous analysis in real world samples, without any cross reactivity, interferences, and false-positives. The detection limits realized by the proposed sensor, under optimized analytical conditions, were found to be as low as 0.028, 0.028,0.061 and 0.029 ng mL-1 for dopamine and 0.017, 0.018, 0.019 and 0.020 ng mL-1 for epinephrine (S/N = 3) in aqueous, blood serum, urine and pharmaceutical samples. Such sensor could be considered suitable for the primitive diagnosis of several chronic diseases, manifested at ultra-trace level.

Metabolomics Reveal That Octocrylene Accumulates in Pocillopora damicornis Tissues as Fatty Acid Conjugates and Triggers Coral Cell Mitochondrial Dysfunction.

Octocrylene (OC) is an ingredient used in many sunscreens and cosmetics worldwide. Our group evaluated the toxicity of OC in corals. Adult Pocillopora damicornis coral was treated with OC at concentrations of 5, 50, 300, and 1000 µg/L. Most polyps were closed at concentrations of 300 µg/L and higher. Further, metabolomic profiling provided crucial information regarding OC accumulation in coral tissues and OC toxicity. First, we demonstrated that OC was transformed into fatty acid conjugates via oxidation of the ethylhexyl chain, yielding very lipophilic OC analogues that accumulate in coral tissues. Second, the differential analysis of coral profiles revealed higher levels of 15 acylcarnitines, suggesting abnormal fatty acid metabolism related to mitochondrial dysfunction. The formation of OC analogues suggests that OC concentrations measured in the environment, and organisms may have been largely underestimated. Overall, these results call for an in-depth evaluation of OC toxicity and the reevaluation of the actual OC accumulation rate in the ocean's food chain, including OC-fatty acid conjugates.

Moisturizers: A Comparison Based on Allergens and Economic Value.

BACKGROUND: The economic burden of cosmetics, such as moisturizers, has been increasing. Despite the high price of some market moisturizers, there have been no studies evaluating the allergenicity of these products. OBJECTIVE: The aim of this study was to evaluate the potential allergens within moisturizers based on economic value, by analyzing the substances found in moisturizers available online at the largest drugstore chain-CVS Health (CVS Health, Woonsocket, RI). METHODS: In this cross-sectional study, ingredients found in 50 expensive and 50 inexpensive moisturizers were matched with sensitizers within the Core Allergen Series published by the American Contact Dermatitis Society and the North American Contact Dermatitis Group. Student t test was used to compare the mean number of allergens present in each group. A χ test or Fisher exact test, where necessary, was used to compare the rates of specific allergen groups between the expensive and inexpensive products. RESULTS: Twenty-six allergenic substances were present overall in the 100 total products surveyed. The expensive moisturizers averaged significantly more allergens per product (8.28 vs 5.60, P = 0.003) than the inexpensive products. CONCLUSIONS: The sensitizing potential of expensive moisturizers may be higher than that of inexpensive moisturizers. Physicians may counsel cosmetic-induced allergic contact dermatitis (ACD) patients that monetary value is not a suitable proxy for evaluating the risk of ACD.

Environmental occurrence and hazard of organic UV stabilizers and UV filters in the sediment of European North and Baltic Seas.

UV absorbing compounds are of emerging concern due to their large production volumes, their persistence or pseudo-persistence, and their potential adverse effects. This is the first study investigating the environmental occurrence and potential hazard of organic UV stabilizers and UV filters in the North and Baltic Sea surface sediments, including the connecting Skagerrak and Kattegat straits. In total, nineteen substances were identified over the entire study area, including the rarely studied compounds ethylhexyl triazone (EHT) and bisoctrizole (UV-360). Octocrylene (OC) was the predominant compound in this study with regard to detection frequency (79%) and concentrations (up to 9.7 ng/g dw). OC accounted for more than 65% of UV stabilizer contamination in the German Bight. The triazine derivative EHT was quantified in the Rhine-Meuse-Delta and the German Bight in concentrations up to 2.0 ng/g dw. In the Baltic Sea, benzotriazole UV stabilizers accounted for 60% of the contamination, with UV-360 as the main substance. The estimated environmental hazard quotients indicated a negligible impact on benthic and sediment-dwelling organisms in the North and Baltic Seas. Region-specific contamination pattern and riverine influences were revealed. The results suggest that both direct and indirect sources contribute to the UV stabilizer and UV filter contamination in the study area.

Simple method for the determination of personal care product ingredients in lettuce by ultrasound-assisted extraction combined with solid-phase microextraction followed by GC-MS.

A simple method for the simultaneous determination of personal care product ingredients: galaxolide, tonalide, oxybenzone, 4-methylbenzyliden camphor, padimate-o, 2-ethylhexyl methoxycinnamate, octocrylene, triclosan, and methyl triclosan in lettuce by ultrasound-assisted extraction combined with solid-phase microextraction followed by gas chromatography with mass spectrometry was developed. Lettuce was directly extracted by ultrasound-assisted extraction with methanol, this extract was combined with water, extracted by solid-phase microextraction in immersion mode, and analyzed by gas chromatography with mass spectrometry. Good linear relationships (25-250 ng/g, R2  > 0.9702) and low detection limits (1.0-25 ng/g) were obtained for analytes along with acceptable precision for almost all analytes (RSDs < 20%). The validated method was applied for the determination of personal care product ingredients in commercial lettuce and lettuces grown in soil and irrigated with the analytes, identifying the target analytes in leaves and roots of the latter. This procedure is a miniaturized and environmentally friendly proposal which can be a useful tool for quality analysis in lettuce.

Adsorption and leaching of novel fungicide pyraoxystrobin on soils by 14C tracing method.

Pyraoxystrobin, (E)-2-(2-((3-(4-chlorophenyl)-1-methyl-1H-pyrazole-5-yloxy)methyl)phenyl)-3-methoxyacrylate, is a newly developed strobilurin fungicide with high antifungal efficiency. It has high potential to enter soil environments that might subsequently impact surface and groundwater. Therefore, 14C-labeled pyraoxystrobin was used as a tracer to study the adsorption/desorption and migration behavior of this compound under laboratory conditions in three typical agricultural soils. The adsorption isotherms conformed with the Freundlich equation. Single factor analysis showed that organic matter content was the most important factor influencing the adsorption. The highest adsorption level was measured in soil with low pH and high organic carbon content. Once adsorbed, only 2.54 to 6.41% of the adsorbed compound could be desorbed. In addition, the mobility results from thin-layer chromatography and column leaching studies showed that it might be safe to use pyraoxystrobin as a fungicide without causing groundwater pollution from both runoff and leaching, which might be attributed to its strong hydrophobicity. High organic matter content enhanced pyraoxystrobin adsorption and desorption because of the rule of similarity (lipid solubility). In the column leaching study, 95.02% (minimum value) of the applied 14C remained within the upper 4.0-cm layer after 60 days.

Developmental toxicity and potential mechanisms of pyraoxystrobin to zebrafish (Danio rerio).

As a newly developed, highly efficient strobilurin fungicide, pyraoxystrobin has been reported to be highly toxic to some aquatic organisms. However, the toxicity of pyraoxystrobin to different life stages of fish and the potential underlying mechanisms are still unknown. Hence, in the present study, the acute toxicity of pyraoxystrobin to different life stages of zebrafish (embryo, larva, and adult) was assessed. The developmental toxicity of pyraoxystrobin to zebrafish embryos and its effects on gene transcription in the embryo were also investigated. The results showed that the 96-h LC50 values of pyraoxystrobin to embryos [2h post-fertilization (hpf)], 12h post-hatching (hph) larvae (84 hpf), 72 hph larvae (144 hpf), and adult zebrafish were 4.099, 1.069, 3.236, and 5.970µg/L, respectively. This suggests that pyraoxystrobin has very high toxicity to different life stages of zebrafish, while the newly hatched larvae constitute the most sensitive period of zebrafish to pyraoxystrobin. Decreased heart rate, hatching inhibition, growth regression, and morphological deformities were observed in zebrafish embryos after acute exposure to different concentrations of pyraoxystrobin. The rate of malformation increased in a time- and concentration-dependent manner in embryos, and the most pronounced abnormality was pericardial edema and yolk sac edema. Pyraoxystrobin (2 and 4µg/L) significantly altered the mRNA levels of genes related to mitochondrial respiratory chain and ATP synthesis (NDI, uqcrc, and ATPo6), oxidative stress (Mn-Sod, Cat, and Gpx), apoptosis (p53, Bcl2, Bax, and Cas3), and immune system (TNFα, IFN, and IL-1b) in zebrafish embryos. This result indicates that the alteration of these genes is a potential mechanism underlying the toxic effects of pyraoxystrobin on zebrafish.

Occurrence of pharmaceuticals and UV-filters in riverine run-offs and waters of the German Baltic Sea.

The occurrence of pharmaceuticals and personal care products (PPCPs) in the marine environment is of great concern. This study was done to determine the emergence of eight pharmaceuticals and eleven ultraviolet filters (UV-Filters) in 5 rivers/streams discharging into the Baltic Sea. Furthermore, a focus was put on the influence of wastewater treatment plant as indirect source and the occurrence of the PPCPs in close beach proximity. Two pharmaceuticals (sulfamethoxazole, salicylic acid) and two UV-filters (2-phenylbenzimidazole-5-sulfonic acid, octocrylene) were detected in all analyzed water samples, with concentration ranging from 0.6ng/L to 836.3ng/L. In all rivers the PPCP concentration decreases towards the Baltic Sea. Sulfamethoxazole was detected at comparable concentration along the coast, which leads to the assumption of stable concentration in beach proximity. Along the coast UV-filters appeared in varying concentrations, leading to the conclusion that the direct input into the marine environment plays a bigger role than the indirect input.

Accurate determination of residual acrylic acid in superabsorbent polymer of hygiene products by headspace gas chromatography.

This work reports on a method for the determination of residual acrylic acid (AA) in the superabsorbent polymers for hygiene products by headspace analysis. It was based on water extraction for the polymer sample at a room temperature for 50min. Then, the AA in the extractant reacted with bicarbonate solution in a closed headspace sample vial, from which the carbon dioxide generated from the reaction (within 20min at 70°C) was detected by gas chromatography (GC). It was found that there is adsorption partition equilibrium of AA between solid-liquid phases. Therefore, an equation for calculating the total AA content in the original polymers sample was derived based on the above phase equilibrium. The results show that the HS-GC method has good precision (RSD<2.51%) and good accuracy (recoveries from 93 to 105%); the limit of quantification (LOQ) was 373mg/kg. The present method is rapid, accurate, and suitable for determining total residual acrylic acid in a wide variety of applications from processing of superabsorbent polymer to commercial products quality control.