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N-nitrosodimethylamine (NDMA) is a hepatotoxic agent and carcinogen contaminant in commonly used medications such as valsartan, losartan, irbesartan, and ranitidine. NDMA can be produced during manufacture, introduced from contaminated ingredients procured elsewhere, or introduced from contaminated solvents and catalysts. The Food and Drug Administration has established a maximum dose of NDMA that is permissible per tablet and guidance for manufacturers. However, many unanswered questions about NDMA contamination need rigorous investigation.

Despite the high abundance in the atmosphere, alcohols in general and methanol in particular are believed to play a small role in atmospheric new particle formation (NPF) largely due to the weak binding abilities of alcohols with the major nucleation precursors, e.g., sulfuric acid (SA) and dimethylamine (DMA). Herein, we identify a catalytic reaction that was previously overlooked, namely, the reaction between methanol and SO3, catalyzed by SA, DMA, or water. We found that alcohols can have unexpected quenching effects on the NPF process, particularly in dry and highly polluted regions with high concentrations of alcohols. Specifically, the catalytic reaction between methanol and SO3 can convert methanol into a less-volatile species-methyl hydrogen sulfate (MHS). The latter was initially thought to be a good nucleation agent for NPF. However, our simulation results suggest that the formation of MHS consumes an appreciable amount of atmospheric SO3, disfavoring further reactions of SO3 with H2O. Indeed, we found that MHS formation can cause a reduction of SA concentration up to 87%, whereas the nucleation ability of MHS toward new particles is not as good as that of SA. Hence, a high abundance of methanol in the atmosphere can lower the particle nucleation rate by as much as two orders of magnitude. Such a quenching effect suggests that the recently identified catalytic reactions between alcohols and SO3 need to be considered in atmospheric modeling in order to predict SA concentration from SO2, while also account for their potentially negative effect on NPF.

Methods for determining the genotoxic impurity N-nitrosodimethylamine (NDMA) in valsartan drug substance by gas chromatography (GC) with mass-spectrometric detection in SIM and MRM modes using direct introduction and vapor-phase analysis are compared. The obtained LOQ and DL differed insignificantly. The test results led to the conclusion that use of a method corresponding to the capabilities and equipment of the laboratory was advisable.

By introducing functional groups such as quaternary amine groups, sulfonic acid groups, triazine groups, and other mespore nanomaterials into the hydrogel, better separation effect of some organic framework materials has been obtained. Due to a reasonable design and preparation strategy, the hydrogel composite-modified silica can be used in the selective separation of various analytes such as pesticides, alkylbenzenes, polycyclic aromatic hydrocarbons, nucleosides/bases, benzoic acids, antibiotics, and carbohydrates. Through the exploration of chromatographic retention behavior, it is proved that the column can be used in mixed-mode liquid chromatography. The intra-day relative standard deviation for retention time of this new stationary phase is 0.12-0.16% (n = 10), and the inter-day relative standard deviation is less than 0.39% (n = 5). This new stationary phase can also be used for separation in complex samples. The limit of detection (LOD) for chlorotoluron in farm irrigation water is 0.21 µg/L and the linear range is 2-250 µg/L. After optimizing the chromatographic conditions, the highest efficiency of the hydrogel column in RPLC and HILIC modes has reached 32,400 plates/m (chlorobenzuron) and 41,300 plates/m (galactose). This new type of hydrogel composite is a porous network material with flexible functional design and simple preparation method and its application has been expanded in liquid chromatography separation successfully. The hydrogel composed of triallyl cyanate cross-linking agent and 3-(2-(methacryloyloxy) ethyl) dimethylamine) propane-1-sulfonate (SBMA) monomer which were co-modified on the surface of mesoporous silica with MOF-919 for separation in mixed-mode liquid chromatography.

Synergistic effects between different bases can greatly enhance atmospheric sulfuric acid (SA)-base cluster formation. However, only the synergy between two base components has previously been investigated. Here, we extend this concept to three bases by studying large atmospherically relevant (SA)3(base)3 clusters, with the bases ammonia (A), methylamine (MA), dimethylamine (DMA), trimethylamine (TMA) and ethylenediamine (EDA). Using density functional theory—ωB97X-D/6-31++G(d,p)—we calculate the cluster structures and vibrational frequencies. The thermochemical parameters are calculated at 29,815 K and 1 atm, using the quasi-harmonic approximation. The binding energies of the clusters are calculated using high level DLPNO-CCSD(T0)/aug-cc-pVTZ. We find that the cluster stability in general depends on the basicity of the constituent bases, with some noteworthy additional guidelines: DMA enhances the cluster stability, TMA decreases the cluster stability and there is high synergy between DMA and EDA. Based on our calculations, we find it highly likely that three, or potentially more, different bases, are involved in the growth pathways of sulfuric acid-base clusters.

Dear Editor,We have reviewed this article ‘DOI: 10.1080/14740338.2021.1917547,’ first published online 22 April 2021. The materials analyzed for nitrite and nitrate include POLYOX™ Polyethylene Oxi...

N-nitrosamines have been linked with cancer in humans due to their presence in drinking water and diets. This study evaluated the role of betulinic acid (BA) in abating oxidative stress, inflammation, and hyperlipidemia in rats treated with N-nitrosodimethylamine (NDMA). Twenty-four male rats were assigned into four equal groups. Group I served as the control, Group II received BA (25 mg/kg), Group III received NDMA (5 mg/kg) and, Group IV received BA (25 mg/kg) and NDMA (5 mg/kg). Results showed that the administration of NDMA significantly (p < 0.05) elevated malondialdehyde in the liver and kidney relative to controls. Activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase, and the level of glutathione were significantly (p < 0.05) decreased by NDMA, while treatment with BA elevated the activities of these enzymes in the liver and kidney. The BA lowered serum interleukin-6 and tumor necrosis factor-alpha levels against the NDMA effect. Furthermore, NDMA increased hepatic and renal triglyceride while phospholipids levels were decreased. NDMA significantly modulated the activities of drug-metabolizing enzymes (aniline hydroxylase, aminopyrine-N-demethylase, and uridyldiphosphoglucuronyltransferase), while BA was able to restore these enzymes to values close to controls. Histology revealed the presence of infiltration and fibroplasia in the liver, while cortical degeneration was noticed in the kidney in NDMA-administered rats. These lesions were reduced in the NDMA rats treated with BA. The findings suggest that BA improves NDMA-induced damage in the liver and kidney of rats through reactions that can be linked with antioxidant, anti-inflammatory, and lipid-lowering pathways.

Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide (NO) synthase inhibitor, inhibits NO synthesis and contributes to the pathogenesis of many human diseases. In adults, ADMA has been identified as a biomarker for chronic kidney disease (CKD) progression and cardiovascular risk. However, little attention is given to translating the adult experience into the pediatric clinical setting. In the current review, we summarize circulating and urinary ADMA reported thus far in clinical studies relating to kidney disease in children and adolescents, as well as systematize the knowledge on pathophysiological role of ADMA in the kidneys. The aim of this review is also to show the various analytical methods for measuring ADMA and the issues tht need to be addressed before transforming to clinical practice in pediatric medicine. The last task is to suggest that ADMA may not only be suitable as a diagnostic or prognostic biomarker, but also a promising therapeutic strategy to treat pediatric kidney disease in the future.

In this study, nanoscale zero-valent iron (nZVI) was added to motivate the functions of all the reactive oxidation species in peracetic acid (PAA) mixture under ultraviolet (UV) irradiation, and to enhance the removal of spiramycin, which is a typical precursor of N-nitrosodimethylamine (NDMA). Spiramycin (≤ 10 mg/L) could be completely removed within 20 min under the conditions of an initial pH of 4.0, a nZVI dose of 0.02 g/L and a PAA dose of 3.0 mg/L; additionally, 95.8% and 78.8% of PAA and H2O2 were consumed during the process. Electron paramagnetic resonance analysis and quenching experiments confirmed that 52.4% and 44.8% of spiramycin removal was contributed by hydroxyl radical (•OH) and carbon-centered radicals (R-C•), respectively; and Fe2+ released from nZVI played a critical role in radicals generation. Four degradation pathways of spiramycin were proposed and verified by the density of functional theory analysis. 65.2% of the NDMA formation potential (FP) was reduced after the reaction, and its residual was mainly contributed by the undegraded intermediate of dimethylamine. The results of multiple characterizations and continuous degradation experiments indicated that nZVI was stable in the system as the removal of spiramycin was hardly influenced even if reused three times. The nZVI/UV/PAA process is a promising advanced oxidation technology not only for the removal of refractory NDMA precursors (such as spiramycin) but also for significantly lowering the NDMA FP.

Developing highly competent and low-cost earth-plentiful metal-based oxygen evolution reaction (OER) electrocatalysts is critical for future electrochemical conversion technologies and renewable energy systems. Herein, two cobalt-based metal-organic frameworks (Co-MOFs), [Co6(btc)2(DMF)6(HCOO)6] (2D, MOF 1) and [Co3(CHOO)9{DMA}3] (3D, MOF 2), where btc = 1,3,5-benzenetricarboxylic acid, DMF = N,N-dimethylformamide, and DMA = dimethylamine, have been crystallized under hydrothermal conditions, from a single reaction. MOF 1 shows an extraordinary OER performance with 175 mV overpotential to attain 10 mA cm-2 current density with a low Tafel slope value of 80 mV dec-1, whereas MOF 2 achieves 10 mA cm-2 current density at 389 mV overpotential. Two different architecture-based MOFs have been synthesized from a single solution for the very first time. Also, the OER activity of MOF 1 overpowers the commercially used RuO2 and surpasses most of the reported OER electrocatalysts. Post OER characterization of MOF 1 revealed the in situ formation of Co(OH)2 and CoOOH, acting as active sites for the OER process.

Background For nearly three years, the concerns regarding trace levels of N-nitrosamines in pharmaceuticals and the associated cancer risk have significantly expanded and are a major issue facing the global pharmaceutical industry. N-nitrosodimethylamine (NDMA) found in formulations of the popular anti-diabetic drug metformin is a prominent example. This has resulted in product recalls raising the profile within the media. Issues of method robustness, sample preparation and several unexpected sources of nitrosamine contamination have been highlighted as false positive risks. It has become apparent that the identification of the root causes of artefactual formation of nitrosamines must be identified to mitigate risk associated with the analysis. Methods A comparison study between four laboratories, across three companies was designed, employing orthogonal mass spectrometric methods for the quantification of NDMA in two metformin immediate release (IR) formulations and one extended release (XR) formulation. These were 2x LC-MS/MS, GC–MS/MS and GC-HRMS. Results Good agreement of results was obtained for the IR formulations. However, we measured higher concentrations of NDMA in the XR formulation using GC-MS/MS compared to LC-MS/MS. We could show that this was due to artefactual (in situ) formation of NDMA when samples were extracted with dichloromethane. Removal of dimethylamine (DMA) and nitrite from the extracted sample or the addition of a nitrosation scavenger are shown to be effective remedies. NDMA in situ formation was not observed in 10% MeOH or acetonitrile. Conclusion Metformin pharmaceuticals contain traces of the API impurity DMA as well as inorganic nitrite from excipients. This can lead to artefactual formation of NDMA and hence false positive results if DCM is used for sample extraction. Similar artefacts are likely also in other pharmaceuticals if these contain the secondary amine precursor of the respective nitrosamine analyte.

Using a combination of first principles and semiempirical calculation, we explore the structural, electronic, and optical properties of a wide range of perovskite (ABX3) nanoparticle of different size and composition. The variations of the BX3 backbone structure considered include all possible combinations of the cations B=Pb,Sn and the anions X=Cl,Br,I, while the interstitial cation A is either methylamonium (MA), or formamidinium (FA), or guanidine amine (GA), or dimethylamine (DEA). Our results indicate that the orientational disorder of the A moieties may affect the structural and electronic properties of the NPs while the optical properties exhibit a clear dependence on the NPs’ size and the types of B cations and X anions, but they are quite insensitive to the type of A cation.

Nanoformulations of mononuclear Pt complexes cis-PtCl2 (PPh3 )2 (1), [Pt(PPh3 )2 (L-Cys)] ⋅ H2 O (3, L-Cys=L-cysteinate), trans-PtCl2 (PPh2 PhNMe2 )2 (4; PPh2 PhNMe2 =4-(dimethylamine)triphenylphosphine), trans-PtI2 (PPh2 PhNMe2 )2 (5) and dinuclear Pt cluster Pt2 (μ-S)2 (PPh3 )4 (2) have comparable cytotoxicity to cisplatin against murine melanoma cell line B16F10. Masking of these discrete molecular entities within the hydrophobic core of Pluronic® F-127 significantly boosted their solubility and stability, ensuring efficient cellular uptake, giving in vitro IC50 values in the range of 0.87-11.23 μM. These results highlight the potential therapeutic value of Pt complexes featuring stable Pt-P bonds in nanocomposite formulations with biocompatible amphiphilic polymers.

Achieving high water recovery using reverse osmosis membranes is challenging during water recycling because the increased concentrations of organics and inorganics in wastewater can cause rapid membrane fouling, necessitating frequent cleaning using chemical agents. This study evaluated the potential of membrane distillation to purify reverse osmosis-concentrated wastewater and achieve 98% overall water recovery for potable water reuse. The results indicate that membrane fouling during membrane distillation treatment was low (4% reduction in permeability) until 98% water recovery. In contrast, membrane fouling during reverse osmosis treatments was high (73% reduction in permeability) before reaching 90% water recovery. Furthermore, membrane distillation showed superior performance in removing dissolved ions (99.9%) from wastewater as compared with reverse osmosis (98.9%). However, although membrane distillation removed most trace organic chemicals tested in this study, a negligible rejection (11%) was observed for N-nitrosodimethylamine, a disinfection byproduct regulated in potable water reuse. In contrast, RO treatment exhibited a high removal of N-nitrosodimethylamine (70%). Post-treatment (e.g., advanced oxidation) after reverse osmosis and membrane distillation may be needed to comply with the N-nitrosodimethylamine regulations. Overall, the membrane distillation process had the capacity to purify reverse osmosis concentrate with insignificant membrane fouling.

Nitrosodimethylamine (NDMA) is a nitrosated amine that has been associated with a 10-5 increase in lifetime cancer risk at the ng/L level. NDMA may be formed from a variety of anthropogenic amine precursors during drinking water treatment utilizing chloramines as a disinfectant. In this dissertation, ten veterinary antibiotics were tested for their ability to form NDMA. The antibiotics were tested at different pH, temperature, chlorine to ammonia weight ratio (Cl2/NH3) and time to determine the impact of these factors on formation. Molar conversions ranged from 0.04 to 4.9 percent, with antibiotics containing more than one dimethylamine (DMA) functional group forming significantly more NDMA. The highest formation for most of the compounds was seen near pH 8.4. The effect of Cl2/NH3 ratio, temperature, and hold time was somewhat varied for each chemical, suggesting that the effects of these parameters were compound-specific. This suggests that large-scale farming run-off may be a new source NDMA precursors. NDMA formation is slowed by the presence of natural organic matter (NOM). It is not currently known which components of NOM are responsible for the reduction in NDMA formation. In this dissertation, water containing NOM was fractionated into different MW size groups or separated based on polarity. The high molecular weight NOM fractions (> 10 kDa), polar and charged components were shown to be the most effective in reducing the amount of NDMA formed. Some precursors have high sorption coefficients to NOM, which is the likely mechanism for reduction of NDMA formation from these compounds. Lastly, NDMA formation can be highly impacted by numerous factors relevant to drinking water treatment. In this dissertation, water samples and treatment plant data were collected from approximately 20 drinking water treatment plants in the U.S. and Canada over 2 years. Linear mixed effects models with random intercepts, which account for variability between treatment plants, were used to assess variable significance and create predictive equations. UV254 concentration in the plant influent, sucralose concentration, polyDADMAC concentration, pre-chlorination time, Cl2/NH3 ratio, use of GAC, water pH, and biofiltration were associated with NDMA concentration in the distribution system.

New particle formation (NPF) occurs frequently in various atmospheric environments and it is a major source of ultrafine particles. This study proposes an indicator, I, for the occurrence of NPF in the atmosphere based on the mechanism of H2SO4-amine nucleation. It characterizes the synergistic effects of the governing factors for H2SO4-amine nucleation, including H2SO4 concentration, amine concentrations, the stability of H2SO4-amine clusters, and aerosol surface area concentration. Long-term measurements in urban Beijing were used to validate this indicator. Good consistency was found between this indicator and the occurrence of NPF. NPF was usually observed with I > 1 for typical conditions in urban Beijing. The derivation and expressions of I also indicate a good positive association between the H2SO4 dimer concentration and NPF, as also verified by measurements. I was shown to be also applicable in urban Shanghai. Copyright (c) 2021 American Association for Aerosol Research

Sulfuric acid and dimethylamine vapours in the atmosphere can form molecular clusters, which participate in new particle formation events. In this work, we have produced, measured and identified clusters of sulfuric acid and dimethylamine using an electrospray ionizer coupled with a planar differential mobility analyser, connected to an atmospheric pressure interface time-of-flight mass spectrometer (ESI–DMA–APi-TOF MS). This set-up is suitable for evaluating the extent of fragmentation of the charged clusters inside the instrument. We evaluated the fragmentation of 11 negatively charged clusters both experimentally and using a statistical model based on quantum chemical data. The results allowed us to quantify the fragmentation of the studied clusters and to reconstruct the mass spectrum removing the artifacts due to the fragmentation.

A solvent-free headspace gas chromatography-mass spectrometry (SF-HS-GC/MS) method was developed and validated for screening N-nitrosodimethylamine (NDMA) in various active pharmaceutical ingredients (APIs) and drug products. Experimental parameters such as incubation temperature, incubation time, and sample volume in solvent-free headspace conditions were optimized. The developed SF-HS-GC/MS method was validated in terms of linearity, limit of quantification (LOQ), precision, and accuracy. The results indicated excellent linearity from 5 to 500 ng g-1 with correlation coefficients higher than 0.9999. The LOQ of this method was 5 ng g-1 and matrix effects ranged from 0.97 to 1.11. The accuracy ranged from 92.77 to 106.54% and the precision RSDs were below 5.94%. No significant matrix effect was observed for any of the drug products. Also, artefactual NDMA formation in ranitidine, nizatidine, and metformin was investigated under HS conditions. Adjusted (mild) SF-HS conditions were suggested for precise quantification of NDMA in positive drug products by GC/MS. The present SF-HS-GC/MS method is a promising tool for the screening and determination of toxic NDMA in APIs and drug products.

The occurrence of several disinfectant byproducts has been investigated in swimming pools. Until now, there are only a few studies on nitrosamine, particularly N-nitrosodimethylamine in swimming pool water. This could be due to the lack of a suitable method that is sensitive enough for the measurement of N-nitrosodimethylamine in pool waters. Other disinfectant byproducts formed in pool water widely documented are trihalomethanes, haloacetic acids, halonitromethanes, and chloramines but inadequate information on N-nitrosodimethylamine. This paper provides a review of the nitrogenous disinfectant byproduct in swimming pools and its health implications. Anthropogenic substances introduced by swimmers such as sweat, lotions, and urine contribute to the formation of N-nitrosodimethylamine. The reaction of secondary amines such as dimethylamine with mono/dichloroamines produced dimethyl hydrazine and further undergo oxidation to form N-nitrosodimethylamine. The reaction of chlorine and other disinfectants with these anthropogenic sources in swimming pools cause cancer and asthma in human tissues. Thus, the assessment of N-nitrosodimethylamine in the swimming pool is less well documented. Therefore, the health consequences, mutagenic, and genotoxic potentials of N-nitrosodimethylamine should be the focus of more research studies.

A simple pH fluorescent probe based on dansyl derivative (Bu-Dns) was synthesized via one-step reaction between dansyl chloride and 4-bromobutan-1-amine hydrobromide. The obtained probe showed good selectivity and sensitivity toward H+ in acidic medium over two pH units (~4-2). At pH > 4, Bu-Dns solution emitted yellow fluorescent light, which became gradually weaker with decreasing pH value. At pH below 2, complete fluorescence quenching occurred. The pH response of Bu-Dns was ascribed to the protonation of dimethylamine group. The lack of influence of metal ion on pH response increases the prevalence of Bu-Dns in the potential detection of pH variation in acidic aqueous media. More importantly, it can sense the intracellular pH change in acidic range.

Importance In 2019, the US Food and Drug Administration (FDA) received a citizen petition indicating that ranitidine contained the probable human carcinogenN-nitrosodimethylamine (NDMA). In addition, the petitioner proposed that ranitidine could convert to NDMA in humans; however, this was primarily based on a small clinical study that detected an increase in urinary excretion of NDMA after oral ranitidine consumption. Objective To evaluate the 24-hour urinary excretion of NDMA after oral administration of ranitidine compared with placebo. Design, Setting, and Participants Randomized, double-blind, placebo-controlled, crossover clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) conducted in 18 healthy participants. The study began in June 2020, and the end of participant follow-up was July 1, 2020. Interventions Participants were randomized to 1 of 4 treatment sequences and over 4 periods received ranitidine (300 mg) and placebo (randomized order) with a noncured-meats diet and then a cured-meats diet. The cured-meats diet was designed to have higher nitrites, nitrates (nitrate-reducing bacteria can convert nitrates to nitrites), and NDMA. Main Outcome and Measure Twenty-four–hour urinary excretion of NDMA. Results Among 18 randomized participants (median age, 33.0 [interquartile range {IQR}, 28.3 to 42.8] years; 9 women [50%]; 7 White [39%], 11 African American [61%]; and 3 Hispanic or Latino ethnicity [17%]), 17 (94%) completed the trial. The median 24-hour NDMA urinary excretion values for ranitidine and placebo were 0.6 ng (IQR, 0 to 29.7) and 10.5 ng (IQR, 0 to 17.8), respectively, with a noncured-meats diet and 11.9 ng (IQR, 5.6 to 48.6) and 23.4 ng (IQR, 8.6 to 36.7), respectively, with a cured-meats diet. There was no statistically significant difference between ranitidine and placebo in 24-hour urinary excretion of NDMA with a noncured-meats diet (median of the paired differences, 0 [IQR, −6.9 to 0] ng;P = .54) or a cured-meats diet (median of the paired differences, −1.1 [IQR, −9.1 to 11.5] ng;P = .71). No drug-related serious adverse events were reported. Conclusions and Relevance In this trial that included 18 healthy participants, oral ranitidine (300 mg), compared with placebo, did not significantly increase 24-hour urinary excretion of NDMA when participants consumed noncured-meats or cured-meats diets. The findings do not support that ranitidine is converted to NDMA in a general, healthy population. Trial Registration ClinicalTrials.gov Identifier:NCT04397445

Atmospheric reaction mechanism and dynamics of phenol with nitrogen dioxide dimer were explored by the density functional theory and high-level quantum chemistry combined with statistical kinetic calculations within 220–800 K. The nitric acid and phenyl nitrite, the typical aerosol precursors, are the preponderant products because of the low formation free energy barrier (∼8.7 kcal/mol) and fast rate constants (∼10−15 cm3 molecule−1 s−1 at 298 K). Phenyl nitrate is the minor product and it would be also formed from the transformation of phenyl nitrite in NO2-rich environment. More importantly, kinetic effects and catalytic mechanism of a series of metal-free catalysts (H2O, NH3, CH3NH2, CH3NHCH3, HCOOH, and CH3COOH) on the title reaction were investigated at the same level. The results indicate that CH3NH2 and CH3NHCH3 can not only catalyze the title reaction by lowering the free energy barrier (about 1.4–6.5 kcal/mol) but also facilitate the production of organic ammonium nitrate via acting as a donor-acceptor of hydrogen. Conversely, the other species are non-catalytic upon the title reaction. The stabilization energies and donor-acceptor interactions in alkali-catalyzed product complexes were explored, which can provide new insights to the properties of aerosol precursors. Moreover, the lifetime of phenol determined by nitrogen dioxide dimer in the presence of dimethylamine may compete with that of determined by OH radicals, indicating that nitrogen dioxide dimer is responsible for the elimination of phenol in the polluted atmosphere. This work could help us thoroughly understand the removal of nitrogen oxides and phenol as well as new aerosol precursor aggregation in vehicle exhaust.

In this study, spatiotemporal heterogeneities in the concentrations of alkaline gases and their particulate counterparts in the marine atmosphere over China's marginal seas were investigated in terms of causes and chemical conversion during two winter cruise campaigns, using semi-continuous measurements made by an onboard URG-9000D Ambient Ion Monitor-Ion chromatograph (AIM-IC, Thermofisher). During the cruise campaign over the East China Sea on December 27, 2019–January 6, 2020, the concentrations of atmospheric trimethylamine (TMAgas) varied by approximately one order of magnitude, with an average (±standard deviation) of 0.10 ± 0.04 µg m−3. Corresponding means were 0.037 ± 0.011 µg m−3 over the Yellow Sea on 7–16 January 2020 and 0.031 ± 0.009 μg m−3 over the Yellow Sea and the Bohai Sea on 9–22 December 2019. In contrast, the simultaneously observed concentrations of TMA in PM2.5, detected as TMAH+, over the East China Sea were 0.098 ± 0.068 µg m−3 and substantially smaller than 0.28 ± 0.18 μg m−3 over the Yellow Sea and the Bohai Sea on 9–22 December 2019. A significant correlation between TMAgas and particulate TMAH+ was obtained over the East China Sea, but no correlation existed over the Yellow Sea and Bohai Sea. The proportional or disproportional variations in concentrations of TMAgas with particulate TMAH+ over the sea zones were likely attributed to the difference in enrichment of TMAH+ in the sea surface microlayer. In addition, spatiotemporal heterogeneities in concentrations of atmospheric ammonia (NH3gas), atmospheric dimethylamine (DMAgas), and DMA in PM2.5, detected as DMAH+, were also investigated. Case analyses were performed to illustrate the formation and chemical conversion of particulate aminium ions in marine aerosols. Finally, we hypothesized a release of basic gases and particulate counterparts from the ocean to the atmosphere, together with secondary formation of DMAH+ and chemical conversion of TMAH+, in the marine atmosphere.

Clonorchis sinensis, a high-risk pathogenic human liver fluke, provokes various hepatobiliary complications, including epithelial hyperplasia, inflammation, periductal fibrosis, and even cholangiocarcinogenesis via direct contact with worms and their excretory–secretory products (ESPs). These pathological changes are strongly associated with persistent increases in free radical accumulation, leading to oxidative stress-mediated lesions. The present study investigated C. sinensis infection- and/or carcinogen N-nitrosodimethylamine (NDMA)-associated fibrosis in cell culture and animal models. The treatment of human cholangiocytes (H69 cells) with ESPs or/and NDMA increased reactive oxidative species (ROS) generation via the activation of NADPH oxidase (NOX), resulting in augmented expression of fibrosis-related proteins. These increased expressions were markedly attenuated by preincubation with a NOX inhibitor (diphenyleneiodonium chloride) or an antioxidant (N-acetylcysteine), indicating the involvement of excessive NOX-dependent ROS formation in periductal fibrosis. The immunoreactive NOX subunits, p47phox and p67phox, were observed in the livers of mice infected with C. sinensis and both infection plus NDMA, concomitant with collagen deposition and immunoreactive fibronectin elevation. Staining intensities are proportional to lesion severity and infection duration or/and NDMA administration. Thus, excessive ROS formation via NOX overactivation is a detrimental factor for fibrogenesis during liver fluke infection and exposure to N-nitroso compounds.

PEGylation is a reductive alkylation of a protein N-terminal/α-amine of protein with mPEG chain by reducing agent. To obtain quantitative and site-specific PEGylation, sodium cyanoborohydride is commonly used as a reducing agent. The reduction process of sodium cyanoborohydride produces highly poisonous hydrogen cyanide, which may render the final product toxic. Herein, we have studied various reducing agents such as dimethylamine borane, triethylamine borane, trimethylamine borane, pyridine borane, morpholine borane, 2-picoline borane, and 5-ethyl-2-methyl-pyridine borane were tested as alternatives to sodium cyanoborohydride for the PEGylation of L-asparaginase. The characterization of reacted pegaspargase was carried out by SDS-PAGE, Western blotting, SEC-HPLC, RP-HPLC, SEC-MALS, CD, enzyme activity, and cell proliferation assays using with lymphoblast cells and MTS/PMS as substrate. Pyridine borane was determined to be the best acceptable reducing agent for PEGylation in terms of purity and activity. As a result, instead of sodium cyanoborohydride, pyridine borane can be employed.

Background Helicobacter pylori (HP) has been detected in the hepatobiliary tract of cholangiocarcinoma (CCA) patients in regions both endemic and non-endemic for Opisthorchis viverrini (OV) infection. However, whether H. pylori infection promotes CCA development remains unknown. We investigated CCA development in hamsters induced by a combination of infection with H. pylori and administration of N-nitrosodimethylamine (NDMA) and compared findings with those in an OV plus NDMA group. Materials and methods Eighty-five hamsters were divided into four groups: (1) normal, (2) administered NDMA, (3) infected with cagA+ H. pylori and administered NDMA (HN group), and (4) infected with OV and administered NDMA (ON group). Animals were euthanized at 3 and 6 months post-infection. Histopathological changes of liver and the expression of markers associated with carcinogenesis were studied. Results At 3 months post-infection (p.i.), cholangitis and lymphoid follicles without tumor appearance were noted in the HN group, whereas extensive fibrosis was seen in members of the ON group, 10% of which had developed tumors. At 6 months p.i., 10% of hamsters administered NDMA alone had developed CCA, whereas in the HN and ON groups, 20% and 60% of hamsters, respectively, had developed CCA. Cytokeratin-19 (CK19) expression was observed in the CCA tissues of both the HN and the ON groups, confirming the bile duct origin of the CCA cells. CCA development in the HN group might be inflammation-mediated, as suggested by overexpression of HMGB1, PCNA, IL-8, and 8-OxodG in CCA tissues. Conclusion cagA+ H. pylori infection and carcinogen intake can induce CCA development with slow progression.

Two series of olmutinib derivatives containing an acrylamide moiety were designed and synthesized, and their IC50 values against cancer cell lines (A549, H1975, NCI-H460, LO2, and MCF-7) were evaluated. Most of the compounds exhibited moderate cytotoxic activity against the five cancer cell lines. The most promising compound, H10, showed not only excellent activity against EGFR kinase but also positive biological activity against PI3K kinase. The structure–activity relationship (SAR) suggested that the introduction of dimethylamine scaffolds with smaller spatial structures was more favorable for antitumor activity. Additionally, the substitution of different acrylamide side chains had different effects on the activity of compounds. Generally, compounds H7 and H10 were confirmed as promising antitumor agents.

This study investigated the effects of thirteen (photo/electro) chemical oxidation processes on the formation potential (FP) of N-nitrosodimethylamine (NDMA) during the chloramination of ranitidine in reverse osmosis (RO) permeate and brine. The NDMA-FP varied significantly depending on the pretreatment process, initial pH, and water matrix types. At higher initial pH values ( 7.0), most pretreatments did not reduce the NDMA-FP, presumably because few radical species and more chloramine-reactive byproducts were generated. At pH 7.0, however, electrochemical oxidation assisted by chloride and Fe

To study sea-derived gaseous amines, ammonia, and primary particulate aminium ions in the marine atmospheres of China's marginal seas, an onboard URG-9000D Ambient Ion Monitor-Ion chromatography (AIM-IC, Thermo Fisher) was set up on the front deck of the R/V Dongfanghong 3 to semi-continuously measure the spatiotemporal variations in the concentrations of atmospheric trimethylamine (TMAgas), dimethylamine (DMAgas), and ammonia (NH3gas) along with their particulate matter (PM2.5) counterparts. In this study, we differentiated marine emissions of the gas species originating from continental transport using data obtained from December 9 to 22, 2019 during the cruise over the Yellow and Bohai Seas, facilitated by additional measurements collected at a coastal site near the Yellow Sea during summer 2019. The data obtained during the cruise and the coastal site demonstrated that the observed TMAgas and protonated trimethylamine (TMAH+) in PM2.5 over the Yellow and Bohai Seas overwhelmingly originated from marine sources. During the cruise, there was no significant correlation (P > 0.05) between the simultaneously measured TMAH+ and TMAgas concentrations. Additionally, the concentrations of TMAH+ in the marine atmosphere varied around 0.28 ± 0.18 μg m−3 (average ± standard deviation), with several episodic hourly average values exceeding 1 μg m−3, which were approximately one order of magnitude larger than those of TMAgas (approximately 0.031 ± 0.009 μg m−3). Moreover, there was a significant negative correlation (P

Ceria supported ruthenium nanoparticles (Ru0/CeO2) are synthesized by impregnation of Ru3+ ions on CeO2 powders followed by sodium borohydride reduction of Ru3+/CeO2. Their characterization was achieved using analytical methods including TEM, XRD, BET, SEM, and XPS. All the results reveal the formation of ruthenium(0) nanoparticles in 1.8 ± 0.3 nm size on CeO2 support. Ru0/CeO2 nanoparticles show high activity in catalyzing the H2 evolution from dimethylamine borane (DMAB). Ru0/CeO2 nanoparticles with 0.55% wt Ru provide the highest turnover frequency (812 h−1) for releasing H2 from DMAB at 60 °C and a total of 2500 turnovers before deactivation. High activity of Ru0/CeO2 nanoparticles for catalytic dehydrogenation of DMAB is attributable to the reducible nature of CeO2 support. Ce3+ defects formation in ceria under reducing conditions of dehydrogenation causes accumulation of negative charge on the oxide support, which makes oxide surface attractive for the ruthenium(0) nanoparticles. This, in turn, causes an enhancement in the metal-support interaction and thus in catalytic activity. The XPS analysis of bare ceria and Ru0/CeO2 demonstrates the increase in the concentration of Ce3+ defects after catalysis. Ru0/CeO2 nanoparticles are also reusable catalyst for H2 evolution from DMAB retaining 40% of initial activity after 4th run of reaction. The catalytic activity of Ru0/CeO2 nanoparticles and activation energy of catalytic dehydrogenation are compared with those of the other ruthenium based catalysts known in literature.

The effective coagulation aid epichlorohydrin-dimethylamine was synthesized, its co-effect with three ferric iron species in polyferric chloride on humic acid elimination and membrane pollution in coagulation-ultrafiltration hybrid technique were appraised to improve the hybrid water treatment technology and generate cleaner water production by this research. To be specific, dosages of polyferric chlorides 2 and polyferric chlorides&epichlorohydrin-dimethylamine were adjusted according to their coagulation performance in jar tests. Furthermore, properties of generated flocs such as floc size (median particle diameter), strength/recovery factor and fractal dimension feature were monitored and combined with results of membrane fouling resistance under various shear forces to understand the mechanism of membrane fouling. Results indicated that epichlorohydrin-dimethylamine can observably enhance the coagulation performance of all polyferric chlorides, especially at low dosage of 4 mg/L. The higher the epichlorohydrin-dimethylamine dosage, the higher removal efficiencies achieved. In particular, for polyferric chloride with basicity of 1.5, the removal efficiency for dissolved organic carbon raised approximately from 15% to 32% as epichlorohydrin-dimethylamine dosage increased from zero to 1.5 mg/L. Meanwhile, for ultra-membrane 3 applied in this study, addition of the epichlorohydrin-dimethylamine also significantly reduced the total membrane fouling resistance of all coagulated water samples by forming cake layer of low compactness and reducing residual micro-particles, 4 even when shearing forces was introduced. Thereinto, the total membrane fouling resistance reduction of polyferric chloride with basicity of 1.5 was the most obvious, which dropped from 2.8 × 108 m−1 to 2.3 × 108 m−1, approximately.

N-Nitrosodimethylamine is a flammable, volatile, oily liquid with a yellow color and a weak, characteristic odor. It is obtained by the nitrosation of amines and ammonium salts. It is used in many technological processes in the rubber industry (as a vulcanization accelerator and antioxidant), leather industry (for hair removing), foundry and agriculture. N-Nitrosodimethylamine may be formed as a result of changes of nitrates added to the food products as preservatives; and endogenously in the gastrointestinal tract (in the reaction of amines and amides with nitrites formed from nitrates by denitrifying bacteria). In Poland, in the years 2005-2016, several dozen to several hundred people per year were exposed) on N-nitrosodimethylamine (in 3-7 plants). According to the measurements made in 1990, the highest concentrations, at which rubber industry workers in Poland were exposed, were 4.5 ÷ 9.2 µg/m3. Acute poisoning with N-nitrosodimethylamine in humans occurred as a result of accidents or criminal activities. At that time, mainly liver damage (necrosis) and hemorrhagic changes associated with a decrease in clotting time were observed. No data are available on the toxic effects of occupational exposure to N-nitrosodimethylamine. After intragastric administration of N-nitrosodimethylamine to rats, LD50 was below 50 mg/kg bw. The sensitivity of laboratory animals (expressed in LD50) increases with their size and decreases with the relative weight of the liver. Administration of N-nitrosodimethylamine to animals at doses of 20 ÷ 40 mg/kg bw. caused hepatic necrosis, leading to death. After a single intraperitoneally, intramuscularly or subcutaneously administration of the compound to rats in the doses of 18 ÷ 30 mg/kg a shortened lifespan and tumors, mainly of kidneys and liver were observed. In mice treated with the compound intraperitoneally or subcutaneously in doses of 0.5 ÷ 14 mg/kg primarily lung cancer was found. After doses of 7 ÷ 15 mg/kg liver and kidney tumors have also been reported. After 30-week exposure of rats to N-nitrosodimethylamine in drinking water in doses of 0.14 ÷ 0.82 mg/kg/day, liver tumors (at a frequency of 70% to 100%) and lung tumors (5% to 100%) was noted in animals. Chronic orally exposure (45-52 weeks) of rats to N-nitrosodimethylamine at doses of 0.144 ÷ 3.6 mg/kg/day resulted in a dose-dependent increase in the cancer incidence of liver (from 2.7% to 83%), kidneys (in 50% of animals) and lungs (80%); and shortening of lifespan. Increased number of liver and kidney tumors after subcutaneous administration of N-nitrosodimethylamine to hamsters (once a week injections throughout life, at doses of 1.4 ÷ 8.6 mg kg) was also reported. In rats exposed on N-nitrosodimethylamine at concentrations 120, 600 or 3000 µg/m3 for 207 days, concentration-related increases in animal mortality and nasal cancers of 36%, 86% and 53% of animals were observed, respectively. The most information about the relationship between the toxic effects and level of exposure come from an experiment performed on rats, in which N-nitrosodimethylamine was administered chronically in drinking water at doses of 0.001 ÷ 0.697 mg/kg body weight/day (male) or 0.002 ÷ 1.244 mg/kg bw./day (females). The experiment showed that for doses up to 0.2 mg/kg/day, the risk of liver cancer has been increasing (depending on the dose), and females were more sensitive than males. Chronic exposure of laboratory animals (rats, mice, hamsters), irrespective of the route of exposure (intragastric, subcutaneous, inhalation) resulted mainly in liver damage and tumors of the liver, kidneys, lungs and nasal cavity. N-Nitrosodimethylamine showed mutagenic and genotoxic effects in in vitro and in vivo experiments after metabolic activation. This is related to the mechanism of genotoxic and carcinogenic action of the metabolites formed in a reaction of N-nitrosodimethylamine hydroxylation followed by its demethylation. N-Nitrosodimethylamine is a transplacental carcinogen, most pronounced when the compound has been administered to animals at the end of pregnancy. The International Agency for Research on Cancer (IARC) has included N-nitrosodimethylamine to 2A group (probably carcinogenic to humans), ACGIH (2001) has qualified N-nitrosodimethylamine to A3 group (proven carcinogenicity to animals and unknown human carcinogenicity), MAK-Commission - to category 2 (substances that are considered carcinogenic to humans). The European Union, according to the CLP classification, has classified the compound to the category 1B with the inscription "H350 - can cause cancer". EPA has included a compound to group B2 - probably carcinogenic to humans. The basis for the calculation of threshold limit value-time weighted average (TLV-TWA; maximum acceptable concentration – MAC) for N-nitrosodimethylamine was the chronic exposure of rats to the compound in drinking water and observed changes in the liver. On the basis of these studies, an assessment of the risk of an additional tumor was made, which has been used to propose MAC-TWA values at 0.0025 mg/m3 (2.5 μg/m3), for which the cancer risk would be 6.15 · 10-4. There is no basis for the short-term exposure limit (STEL) and biological limit value (BLV). The notations "Carc. 1B" (carcinogenic substance Cat. 1B) and "skin" (absorption through the skin may be as important as in the case of inhalation) were proposed. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Проведена сравнительная оценка методик определения генотоксичной примеси н-нитрозодиметиламина (НДМА) в фармацевтической субстанции валсартана методом ГХ c масс-спектрометрическим детектированием в режимах SIM и MRM с использованием прямого ввода и анализа паровой фазы. Сравнение методик показало незначительные различия в полученных показателях LOQ и LD. По итогу проведенных испытаний был сделан вывод о целесообразности использования метода, отвечающего возможностям и оснащению лаборатории.

We describe a new and direct route to obtain Al-SBA-15-modified materials with different groups on their surface using diazonium salts. For comparison, modification using surfactants was also used. In the present study, we decided to examine the applicability of these materials in the adsorption of compounds released from dental fillings. The effectiveness of modification was proved by results of Fourier transform infrared spectroscopy and energy-dispersive spectrometry. The results indicate the formation of characteristic groups on the surface of the materials. The materials after modification are characterized by smaller surface area and pore volume, which is result of covering the surface with an aryl or surfactant layer. The adsorption properties change after modification and depend on the used modifier. Diazonium modification has a positive effect on sorptive properties when hydroxyl and dimethylamine groups are obtained. The methods of material modification presented in this work may in the future lead to the improvement in the properties of sorbents used in solid-phase extraction.

Palladium(II) 2,4-pentanedionate, impregnated on alumina nanopowder, was reduced by dimethylamine borane (DMAB) forming Pd(0) nanoparticles (NPs) at room temperature. Pd(0) NPs could be isolated from solution and characterized by ATR-IR, UV–vis, XRD, SEM, TEM, XPS and BET. The results obtained from TEM images reveal the formation of palladium(0) nanoparticles on gamma-alumina, having a mean particle size of 7.1 ± 2.6 nm. Alumina supported Pd(0) NPs with various metal loadings were employed as catalyst in dehydrogenation of DMAB at room temperature and the sample with 5.0% wt. Pd provides the highest turnover frequency (TOF = 73 h−1) at 25.0 ± 0.5 °C. Kinetics of the catalytic dehydrogenation was also investigated depending on Pd concentration and temperature to determine the kinetic parameters of the H2 release reaction.

Organic amines, including amine groups and carbon groups, are highly toxic chemicals with regard to both human health and ecosystems. However, the treatment of organic amines in wastewater remains a challenge using existing methods because of poisonousness of amines to microorganisms and simultaneous poor denitrification. In this work, we used a photoelectrochemical-chlorine radicals process to selectively and efficiently degrade organic amines into N2 and CO2. The proposed process was based on the reaction of organic amines with chlorine radicals (Cl ) and hydroxyl radicals (HO ) and a fast reduction reaction of nitrate-N on a porous Pd-Cu/porous nickel cathode (Pd-Cu/PN). For dimethylamine (DMA), this system achieved removal rates of 99.20% and 51.34% for total nitrogen (TN) and total organic carbon (TOC) within 2.5 h, respectively. Four main intermediate products, including methylamine (MA), ammonia (NH4+), nitrate (NO3−) and nitrite (NO2−), were observed, and no chlorohydrocarbon was detected. The analysis of electron-spin resonance (ESR) and a free-radical capture experiment confirmed that free radicals, especially Cl , played an important role in the denitrification of DMA. Trimethylamine (TMA), ethylamine (EA) and diethylamine (DEA) were also degraded to demonstrate the general applicability of this system, and the corresponding TN removal rates were 96.23%, 93.85% and 92.37%, respectively. This work provides a new, efficient, highly selective and environmentally friendly treatment method for removing organic amines from wastewater.

Formaldehyde (FA) in fish is formed as a result of fish quality decreasing, in particular the freshness of fish. The level of fish freshness can not be increased but maintained. Quality of fish can be maintained by proper handling processes, one of them is handling with low temperatures. The purpose of this study was to determine the formation process of FA lizardfish (Saurida tumbil) during freezing storage. The treatments applied were gutted and ungutted. Observations were made every 2 weeks for 22 weeks. The parameters measured were sensoric, pH, total volatile base (TVB), trimethylamine (TMA), formaldehyde (FA) and dimethylamine (DMA). The results obtained showed that FA formed after two weeks. Levels of FA formed in gutted lizardfish are 12.96 ppm and 17.77 ppm for ungutted. Formaldehyde (FA) formation occurs when the condition of the fish is still fresh with TVB content of below 20 mg N/100 g. Dimethylamine (DMA) levels when FA is formed of 7.99 ppm for gutted lizardfish and 5.50 ppm for ungutted. Formaldehyde (FA) formation also accompanied by the increation of other decay indicators.

Methods have been developed for the synthe-sis of a series of monomeric and dimeric surfactants functionalized by an oxime group based on imid-azole, pyridine and alkylamines. Alkyl radicals of varying degrees of branching were used, both as sub-stituents at the nitrogen atom of the head group and as spacers in the formation of dimeric products. This allowed to create a whole spectrum of supramo-lecular systems with different physicochemical pro-perties and reactivity.Methods of obtaining a number of intermedi-ate products were improved, primarily for the reac-tion of the imidazole alkylation using interphase ca-talysis conditons — solid phase-liquid. The method of obtaining surfactants based on imidazole consisted in the interaction of alkylimidazoles with chloro-acetaloxime in a suitable solvent or with chloro-acetone and subsequent reaction with a hydroxyla-mine solution. In the preparation of pyridine-based surfactants, the corresponding oxo-substituted pyri-dine was reacted with a hydroxylamine solution, fol-lowed by reaction of the obtained product with al-kyl halide. A method has been developed for the syn-thesis of functionalized surfactants based on alipha-tic amines, where for monomeric products a path is chosen that is associated with the sequential alkyla-tion of 1-chloroacetoxime with dimethylamine and dodecyl bromide, and for dimeric ones, the direct interaction of 1,3-dichloroacetoxime with 1,1-dime-thyl-1-dodecylamine.The composition, structure and purity of the obtained compounds were confirmed by NMR spec-troscopy, thin-layer chromatography and elemental analysis. NMR spectra were recorded on a BRUKER Avance II 400 instrument (400 MHz), TMS was used as an internal standard. Chromatography in a thin layer of silica gel was performed on Merck Si-licaGel 60 F254 plates (eluent — chloroform: meth-anol = 10:1).The data presented by us testify to the pro-spects of the chosen pathway for structural modifica-tion of surfactants functionalized by the oxime group, and give direction for the further design of such microheterogeneous systems.

CO2 foam can be used for mobility control and blocking gas breakthrough channels during CO2 injection for enhanced oil recovery, and specially designed and formulated foam agents are needed to enhance the stability of the foams especially under reservoir conditions. In this study, the performance of CO2 foams with various surfactants has been investigated, including amide based surfactants (e.g. coconut monoethanol amide (CMEA), lauryl diethanol amide (LDEA)), amine based surfactants (cocoacyl propyl dimethylamine (UC11AMPM)), sodium dodecyl sulfate (SDS) and its mixtures with the amides and amines. A visualized high pressure and high temperature foam meter and a sand-pack flooding setup were used to assess the foam's performance, along with the surface tension measurement of the surfactant solutions in the presence of CO2. The influence of temperature, the surface tension of the aqueous solution, and SDS on CO2 foam performance of amide and amine based surfactant were investigated. The experimental results indicate that the amide or amine based surfactant alone all show poor foam performance, while their CO2 foam stability and their mobility control capability can be greatly enhanced at high temperature up to 100 °C with the salinity of 50000 mg/L. After adding SDS to CMEA, LDEA, or UC11AMPM, an excellent synergistic effect can be formed among the molecules, which can reduce the surface tensions of individual surfactant solution and enhance the stability of CO2 foams.

We report results of the studies relating to the fabrication of a surface plasmon resonance (SPR) based label-free immunosensor for real-time monitoring of endothelin-1 (ET-1), a colon cancer biomarker. A gold disk modified with a self-assembled monolayer (SAM) of 11-mercaptoundecanoic acid (11-MUA) was functionalised via covalent immobilization of monoclonal anti-ET-1 antibodies using EDC-NHS (1-(3-(dimethylamine)-propyl)-3-ethylcarbodiimide hydrochloride, N-hydroxy succinimide) chemistry. This immunosensing platform (ethanolamine/anti-ET-1/11-MUA/Au) was characterized via atomic force microscopy (AFM), contact angle (CA) and Fourier transform infrared (FT-IR) spectroscopic techniques. The fabricated SPR electrode was further used to detect ET-1 in the broad concentration range 2–100 pg mL−1, with a detection limit of 0.30 pg mL−1 and remarkable sensitivity of 2.18 mo pg−1mL. The adsorption mechanism was studied using monophasic model and the values of association (ka) and dissociation (kd) constants for anti-ET-1 and ET-1 binding were calculated to be 4.4 ± 0.4 × 105 M−1 s−1 and 2.04 ± 0.0003 × 10−3 s−1, respectively. The results obtained via analysis of serum samples of colorectal cancer patients were found to be in good agreement with those obtained from enzyme-linked immunosorbent assay (ELISA) technique. Further, electrochemical studies were performed to prove the efficacy of the fabricated platform as a point of care device for the detection of ET-1.