Dimethyl Phosphate Research Articles

Engineering a Mesoporous Silicon Nanoparticle Cage to Enhance Performance of a Phosphotriesterase Enzyme for Degradation of VX Nerve Agent.

The organophosphate (OP)-hydrolyzing enzyme phosphotriesterase (PTE, variant L7ep-3a) immobilized within a partially oxidized mesoporous silicon nanoparticle cage is synthesized and the catalytic performance of the enzyme@nanoparticle construct for hydrolysis of a simulant, dimethyl p-nitrophenyl phosphate (DMNP), and the live nerve agent VX is benchmarked against the free enzyme. In a neutral aqueous buffer, the optimized construct shows a ≈2-fold increase in the rate of DMNP turnover relative to the free enzyme. Enzyme@nanoparticles with more hydrophobic surface chemistry in the interior of the pores show lower catalytic activity, suggesting the importance of hydration of the pore interior on performance. The enzyme@nanoparticle construct is readily separated from the neutralized agent; the nanoparticle is found to retain DMNP hydrolysis activity through seven decontamination/recovery cycles. The nanoparticle cage stabilizes the enzyme against thermal denaturing and enzymatic (trypsin) degradation conditions relative to free enzyme. When incorporated into a topical gel formulation, the PTE-loaded nanoparticles show high activity toward the nerve agent VX in an ex vivo rabbit skin model. In vitro acetylcholinesterase (AChE) assays in human blood show that the enzyme@nanoparticle construct decontaminates VX, preserving the biological function of AChE when exposed to an otherwise incapacitating dose.

Enhancing the high temperature resistance of nanocomposite materials through dimethyl methyl phosphate impregnation‐coating treatment

AbstractIn order to enhance the thermal stability of polyvinyl alcohol (PVA), a modification scheme involving a dimethyl methyl phosphate (DMMP) impregnation‐coating treatment was adopted in this article. Initially, the interfacial compatibility of DMMP with PVA was characterized using scanning electron microscopy (SEM), inductively coupled plasma spectroscopy, elemental analysis and Fourier transform infrared spectroscopy (FTIR). Subsequently, the pyrolysis and combustion properties of DMMP‐coated PVA were evaluated via non‐isothermal thermogravimetric experiments and cone calorimeter tests. The pyrolysis products were then analyzed using a combination of thermogravimetric infrared chromatography and pyrolysis gas chromatography/mass spectrometry (Py‐GC/MS). Finally, a reaction model function closer to the actual co‐pyrolysis mechanism at high temperatures was established through thermal kinetics. The results indicated that the impregnation‐coating treatment could effectively distribute the DMMP molecules on the surfaces of PVA particles. Meanwhile, the DMMP coating could clearly slow the peak degradation rate of PVA grains and inhibit the combustion of PVA under fire conditions. Furthermore, the pyrolysis of DMMP‐coated PVA resulted in the formation of over 40 distinct compounds. The kinetic analysis revealed that the reaction model function established in this article could better characterize the actual reaction mechanism of the co‐pyrolysis of DMMP and PVA.

Complexation of diserinol isophthalamide with phosphorylated biomolecules in electrospray ionization mass spectrometry

Electrospray ionization (ESI) enables gentle transfer of biomolecules from solution to vacuum, facilitating the study of biomolecular structure under highly controlled conditions. However, biomolecules are desolvated during the ESI process, and the loss of ionic hydrogen bonds to solvent molecules can drive structural rearrangement, most prominently at solvent-exposed charge sites. Microsolvation reagents can bind to these bare charge sites in ESI mass spectrometry (ESI–MS) experiments, providing alternative intermolecular interaction partners. Previously, 18-crown-6 was shown to be an effective reagent for binding to cationic monoalkylammonium residues. More recently, diserinol isophthalamide (DIP) was reported as an analogous anionic microsolvation reagent, primarily for carboxylate residues of small model peptides. Herein, we expand upon this work to examine the complexation of DIP, 1,1’-(1,2-phenylene)bis(3-phenylurea) (PBP), and triclocarban (TCC) with molecules featuring a terminal or linking phosphate moiety. Specifically, using ESI–MS, we assess the binding of these reagents with dimethyl phosphate (DMP), cyclic adenosine monophosphate (cAMP), dibutyryl cAMP, RNA dinucleotides ApU and CpG, and angiotensin II phosphate (DRVpYIHPF). For DMP, the smallest target molecule, reagents TCC, PBP and DIP showed favorable adduction. However, for larger systems, PBP and TCC showed reduced complexation, which was attributed to steric hindrance from the terminal aromatic moieties of PBP and the limited hydrogen bonding network of TCC. Overall, of the three reagents, DIP showed the most consistent performance for anionic microsolvation of phosphate groups, facilitating future studies of gas-phase biomolecular structure and the effects of microsolvation.

A green and sensitive electromembrane extraction (EME) method for the determination of dialkylphosphates in maternal urine and amniotic fluid

Organophosphates compounds are extensively used pesticides, whose metabolites, dialkyl phosphates, are considered as bioindicators of human exposure. Recently, research has indicated that they can affect thyroid endocrine function. Pregnant women are a particularly vulnerable cohort to these effects due to concerns about prenatal exposure to environmental pollutants. For the first time an electromembrane microextraction method is proposed for the simultaneous determination of seven dialkylphosphate metabolites in maternal urine and amniotic fluid, which is compatible with mass spectrometry detection and achieves highly sensitive levels of quantitation. Dialkylphosphates were extracted from a 10 mL donor solution at pH 7 into a 50 µL acceptor solution at pH 12 using 1-octanol as the supported liquid membrane and applying 60 V for 10 min at 600 rpm. The obtained extracts were analysed by ion pair liquid chromatography coupled to a triple quadrupole mass spectrometer, using an Acquity UPLC® BEH C18 column (100 mm × 2.1 mm i.d., 1.7 µm particle size) at 30 °C. Under optimal extraction conditions, the preconcentration factors were achieved were up to 178-fold, allowing for high sensitivity levels, in the order of ng mL−1. The limits of quantitation were within 0.075 ng mL−1 (diethyl thiophosphate) and 1.67 ng mL−1 (dimethyl phosphate) in maternal urine samples and within 0.015 ng mL−1 (diethyl thiophosphate) and 0.5 ng mL−1 (dimethyl dithiophosphate) in amniotic fluid samples. The comparative study revealed a significant improvement in terms of analysis time, sensitivity, greenness, and practicality. Finally, the applicability of the method for the determination of selected dialkylphosphates was demonstrated in paired maternal urine and amniotic fluid samples. These results suggest potential placental transfer to the offspring.

Novel 1,3-Dimethylimidazolium Dimethyl Phosphate Ionic Liquid for Efficient Separation of the 1,3,5-Trioxane/Water Azeotropic System by Extractive Distillation: Molecular Insights and Process Enhancement

Novel 1,3-Dimethylimidazolium Dimethyl Phosphate Ionic Liquid for Efficient Separation of the 1,3,5-Trioxane/Water Azeotropic System by Extractive Distillation: Molecular Insights and Process Enhancement

Syntheses, structures and magnetisms of dimethyl phosphate-bridged dinuclear lanthanide complexes with pentadentate macrocyclic ligand

A series of air-stable dinuclear complexes, [HNEt3]2[Ln2(L)2((CH3O)2PO2)4](BPh4)4 (L = 2,14-dimethyl-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadeca1(19), 2,13,15,17-pentene, Ln = Dy, 1-Dy; Tb, 2-Tb; Gd, 3-Gd), has been synthesized and characterized using single-crystal X-ray crystallography and magnetic measurements. The crystal structures disclose that two dimethyl phosphate anions act as bridging ligands, linking two Ln(III) ions. Each Ln(III) ion is eight-coordinated by five nitrogen atoms from a pentadentate Schiff based ligand L and three oxygen atoms from three dimethyl phosphates, forming a triangular dodecahedral coordination geometry. Direct-current magnetic susceptibility measurements indicate an extremely weak antiferromagnetic exchange between Gd(III) ions in 3-Gd. Complex 1-Dy exhibits slow magnetic relaxation with an effective energy barrier (Ueff) of 13 K under an applied field of 1000 Oe, whereas 2-Tb does not exhibit single-molecule magnet behavior. This work presents a novel strategy for constructing polynuclear single-molecular magnets by using a pentadetate macrocycle as magnetic building blocks integrated with replaceable axial ligands.

A novel fluorescent and photothermal probe based on nanozyme-mediated cascade reaction for detecting organophosphorus pesticide residues

In this study, a nanozyme (ZIF-Co-Cys) with high oxidase-like catalytic activity was prepared, and a ratiometric fluorescent/photothermal dual-mode probe was constructed for organophosphorus pesticides (OPs) detection based on the competitive effect of ZIF-Co-Cys and the enzymatic reaction product of acid phosphatase (ACP) on o-phenylenediamine and the inhibition effect of OPs on ACP activity. Using dimethyl dichloroviny phosphate (DDVP) as the model, both the fluorescence intensity ratio and the temperature change of the probe solution exhibited an excellent correlation with OPs concentration. The detection limits were 1.64 ng/mL and 0.084 ng/mL, respectively. Additionally, the detection of DDVP residues in real samples verified the outstanding anti-interference and accuracy of the probe. This work not only provided a complementary dual-mode method for the accurate and rapid detection of OPs residues in complex samples, but also supplied a new insight into the design of a multi-mode sensing platform based on the cascade reaction of nanozyme.

Association between organophosphorus pesticides and obesity among American adults

ObjectiveTo investigate any connections between urinary organophosphorus pesticide (OPP) metabolites and adiposity measures.MethodsIn this study, data from the National Health and Nutrition Examination Survey (NHANES) projects from 2003 to 2008, 2011 to 2012, and 2015 to 2018 were analysed. Obesity was defined as a body mass index (BMI) of 30 kg/m² or higher. Abdominal obesity was defined as a waist circumference (WC) over 102 cm for men and 88 cm for women. Four urinary OPP metabolites (dimethyl phosphate [DMP], diethyl phosphate [DEP], dimethyl phosphorothioate [DMTP], and diethyl phosphorothioate [DETP]) and adiposity measures were examined using multiple linear regression and logistic regression analyses. The correlations between a variety of urinary OPP metabolites and the prevalence of obesity were investigated using weighted quantile sum regression and quantile g-computation regression.ResultsIn this analysis, a total of 9,505 adults were taken into account. There were 49.81% of male participants, and the average age was 46.00 years old. The median BMI and WC of the subjects were 27.70 kg/m2 and 97.10 cm, respectively. Moreover, 35.60% of the participants were obese, and 54.42% had abdominal obesity. DMP, DMTP, and DETP were discovered to have a negative correlation with WC and BMI in the adjusted models. DMP (OR = 0.93 [95% CI: 0.89–0.98]), DEP (OR = 0.94 [95% CI: 0.90–0.99]), DMTP (OR = 0.91 [95% CI: 0.86–0.95]), and DETP (OR = 0.85 [95% CI: 0.80–0.90]) exhibited negative associations with obesity prevalence. Similar correlations between the prevalence of abdominal obesity and the urine OPP metabolites were discovered. Moreover, the mixture of urinary OPP metabolites showed negative associations with adiposity measures, with DMTP and DETP showing the most significant effects.ConclusionTogether, higher levels of urinary OPP metabolites in the urine were linked to a decline in the prevalence of obesity.

Association between organophosphorus insecticides exposure and osteoarthritis in patients with arteriosclerotic cardiovascular disease

BackgroundOrganic phosphorus insecticides (OPPs) are a class of environmental pollutants widely used worldwide with potential human health risks. We aimed to assess the association between exposure to OPPs and osteoarthritis (OA) particularly in participants with atherosclerotic cardiovascular disease (ASCVD).MethodsParticipants’ information was obtained from data in the National Health and Nutrition Examination (NHANES). Weighted logistic regression models were utilized to detect associations between OPPs metabolites and OA. Restricted cubic spline plots (RCS) were drawn to visualize the dose-response relationship between each metabolite and OA prevalence. Weighted quantile sum (WQS) regression and Bayesian kernel-machine regression (BKMR), were applied to investigate the joint effect of mixtures of OPPs on OA.ResultsA total of 6871 samples were included in our study, no significant associations between OPPs exposure and OA incidence were found in whole population. However, in a subset of 475 individuals with ASCVD, significant associations between DMP (odds ratio [OR] as a continuous variable = 1.22, 95% confidence interval [CI]: 1.07,1.28), DEP ((odds ratio [OR] of the highest tertile compared to the lowest = 2.43, 95% confidence interval [CI]: 1.21,4.86), and OA were observed. DMP and DEP showed an increasing dose-response relationship to the prevalence of OA, while DMTP, DETP, DMDTP and DEDTP showed a nonlinear relationship. Multi-contamination modeling revealed a 1.34-fold (95% confidence intervals:0.80, 2.26) higher prevalence of OA in participants with high co-exposure to OPPs compared to those with low co-exposure, with a preponderant weighting (0.87) for the dimethyl dialkyl phosphate metabolites (DMAPs). The BKMR also showed that co-exposure of mixed OPPs was associated with an increased prevalence of OA, with DMP showing a significant dose-response relationship.ConclusionHigh levels of urine dialkyl phosphate metabolites (DAP) of multiple OPPs are associated with an increased prevalence of OA in patients with ASCVD, suggesting the need to prevent exposure to OPPs in ASCVD patients to avoid triggering OA and further avoid the occurrence of cardiovascular events caused by OA.

A smartphone-assisted portable on-site detection system for organophosphorus pesticides in vegetables and fruits based on all-in-one paper-based sensors: 2,2-Dichlorovinyl dimethyl phosphate as a model

The improper use of organophosphate pesticides (OPs) can lead to residue posing a serious threat to human health and environment. Therefore, the development of a simple, portable, and sensitive detection method is crucial. Herein, a bioenzyme-nanozyme-chromogen all-in-one paper-based sensor was synthesized. Initially, the Ce/Zr-MOF with peroxidase-like activity was grown on filter paper (FP) using in-situ solvent thermal method, resulting in Ce/Zr-MOF@FP. Subsequently, the AChE-ChO-TMB system was immobilized onto Ce/Zr-MOF@FP using biocompatible gelatin, which enhanced cascade catalysis efficiency through the proximity effect. Based on the inhibition principle of OPs on AChE, we integrated this sensor with Python-based image recognition algorithm to achieve detection of OPs. Using 2,2-dichlorovinyl dimethyl phosphate (DDVP) as a model of OPs, it has good detection performance with a detection limit of 0.32 ng mL−1 and a recovery rate range of 95–107%. The potential for on-site detection of DDVP residues in vegetables and fruit samples is highly promising.

On the Moisture Absorption Capability of Ionic Liquids.

Due to their many attractive physicochemical properties, ionic liquids (ILs) have received extensive attention with numerous applications proposed in various fields of science and technology. Despite this, the molecular origins of many of their properties, such as the moisture absorption capability, are still not well understood. For insight into this, we systematically synthesized 24 types of ILs by the combination of the dimethyl phosphate anion with various types of alkyl group-substituted cyclic cations─imidazolium, pyrazolium, 1,2,3-triazolium, and 1,2,4-triazolium cations─and performed a detailed analysis of the dehumidification properties of these ILs and their aqueous solutions. It was found that these IL systems have a high dehumidification capability (DC). Among the monocationic ILs, the best performance was obtained with 1-cyclohexylmethyl-4-methyl-1,2,4-triazolium dimethyl phosphate, whose DC (per mol) value is 14 times higher than that of popular solid desiccants like CaCl2 and silica gel. Dicationic ILs, such as 1,1'-(propane-1,3-diyl)bis(4-methyl-1,2,4-triazolium) bis(dimethyl phosphate), showed an even better moisture absorption, with a DC (per mol) value about 20 times higher than that of CaCl2. Small- and wide-angle X-ray scattering measurements of eight types of 1,2,4-triazolium dimethyl phosphate ILs were performed and revealed that the majority of these ILs form nanostructures. Such nanostructures, which vary with the identity of the IL and the water content, fall into three main categories: bicontinuous microemulsions, hexagonal cylinders, and micelle-like structures. Water in the solutions exists primarily in polar regions in the nanostructures; these spaces function as water pockets at relatively low water concentrations. Since the structure and stability of the aggregated forms of the ILs are mainly governed by the interactions of nonpolar groups, the alkyl side chains of the cations play an important role in the DC and temperature-dependent equilibrium water vapor pressure of the IL solutions. Our experimental findings and molecular dynamics simulation results shed light on the moisture absorption mechanism of the IL aqueous solutions from a molecular perspective.

Association of ambient air pollution and pesticide mixtures on respiratory inflammatory markers in agricultural communities

Air pollution exposure is associated with adverse respiratory health outcomes. Evidence from occupational and community-based studies also suggests agricultural pesticides have negative health impacts on respiratory health. Although populations are exposed to multiple inhalation hazards simultaneously, multidomain mixtures (e.g. environmental and chemical pollutants of different classes) are rarely studied. We investigated the association of ambient air pollution-pesticide exposure mixtures with urinary leukotriene E4 (LTE4), a respiratory inflammation biomarker, for 75 participants in four Central California communities over two seasons. Exposures included three criteria air pollutants estimated via the Community Multiscale Air Quality model (fine particulate matter, ozone, and nitrogen dioxide) and urinary metabolites of organophosphate (OP) pesticides (total dialkyl phosphates (DAPs), total diethyl phosphates (DE), and total dimethyl phosphates (DM)). We implemented multiple linear regression models to examine associations in single pollutant models adjusted for age, sex, asthma status, occupational status, household member occupational status, temperature, and relative humidity, and evaluated whether associations changed seasonally. We then implemented Bayesian kernel machine regression (BKMR) to analyse these criteria air pollutants, DE, and DM as a mixture. Our multiple linear regression models indicated an interquartile range (IQR) increase in total DAPs was associated with an increase in urinary LTE4 in winter (β: 0.04, 95% CI: [0.01, 0.07]). Similarly, an IQR increase in total DM was associated with an increase in urinary LTE4 in winter (β:0.03, 95% CI: [0.004, 0.06]). Confidence intervals for all criteria air pollutant effect estimates included the null value. BKMR analysis revealed potential non-linear interactions between exposures in our air pollution-pesticide mixture, but all confidence intervals contained the null value. Our analysis demonstrated a positive association between OP pesticide metabolites and urinary LTE4 in a low asthma prevalence population and adds to the limited research on the joint effects of ambient air pollution and pesticides mixtures on respiratory health.

Covalent adduct formation of histone with organophosphorus pesticides in vitro

It is established that organophosphorus pesticide (OPP) toxicity results from modification of amino acids in active sites of target proteins. OPPs can also modify unrelated target proteins such as histones and such covalent histone modifications can alter DNA-binding properties and lead to aberrant gene expression. In the present study, we report on non-enzymatic covalent modifications of calf thymus histones adducted to selected OPPs and organophosphate flame retardants (OPFRs) in vitro using a bottom-up proteomics method approach. Histones were not found to form detectable adducts with the two tested OPFRs but were avidly modified by a few of the seven OPPs that were tested in vitro. Dimethyl phosphate (or diethyl phosphate) adducts were identified on Tyr, Lys and Ser residues. Most of the dialkyl phosphate adducts were identified on Tyr residues. Methyl and ethyl modified histones were also detected. Eleven amino residues in histones showed non-enzymatic covalent methylation by exposure of dichlorvos and malathion. Our bottom-up proteomics approach showing histone-OPP adduct formation warrants future studies on the underlying mechanism of chronic illness from exposure to OPPs.

Fiber-optic Michelson interferometric trace dimethyl methyl phosphate sensor based on MnO2/ZnO composites film

A dimethyl-methyl phosphonate (DMMP) sensor based on MnO2/ZnO composite film integrated fiber-optic Michelson interference structure is proposed. The sensing structure is formed by a thick taper between a single-mode fiber (SMF) and a four-core fiber (FCF), and then the no-core fiber (NCF) is spliced at the other end of the FCF. To enhance reflection, the silver film was deposited on the end of the NCF, and the fiber optic Michelson interference structure is formed. MnO2/ZnO composite sensing film was deposited on the FCF surface, and the structure, morphology, and properties of the sensing material were analyzed by x-ray diffraction, Scanning electron microscopy, Fourier-transform infrared spectroscopy, x-ray photoelectron spectroscopy, etc. The sensitivity and the response time of the sensor are 0.3478 dB/ppm and 180 s, respectively. The sensor has good selectivity and stability, and it has a good application prospect in trace DMMP detection with high sensitivity.

BF3 Complexing Phosphate/Phosphonate Ionic Liquids: Synthesis, Characterization and Thermophysical Properties.

A new group of BF3 complexing phosphate/phosphonate ionic liquids (ILs) [Emim][X(BF3)2] (X=dimethyl phosphate, diethyl phosphate, methyl phosphonate, and ethyl phosphonate) were synthesized and characterized. Key thermophysical properties of the new complex ionic liquids, including density, viscosity, conductivity, surface tension, solid-liquid phase transition, and thermal stability were determined and compared with those of [Emim][X]. Some other important thermophysical properties such as isobaric thermal expansion coefficient, molecular volume, standard molar entropy, and lattice potential energy were obtained from measured density data, and the free volume was estimated by a linear equation presented in this article, while critical temperature, normal boiling temperature, and enthalpy of vaporization were estimated from measured surface tension and density data. Furthermore, Fragility study shows that [Emim][X(BF3)2] should be considered as fragile liquids, while [Emim][X] could be considered as extremely fragile liquids. The ionicity of [Emim][X(BF3)2] was predicted by Walden rule, and the result shows that these ILs fit well with Walden law. The key features of these complex ILs are their extremely low glass transition (-95.33~-98.46 °C) without melting, considerably low viscosities (33.876~58.117 mPa ⋅ s), and high values of free volume fraction (comparable to [Omim][BF4], [Emim][NTf2], and [Emim][TCB]).

Urethane Synthesis in the Presence of Organic Acid Catalysts-A Computational Study.

A general mechanism for catalytic urethane formation in the presence of acid catalysts, dimethyl hydrogen phosphate (DMHP), methanesulfonic acid (MSA), and trifluoromethanesulfonic acid (TFMSA), has been studied using theoretical methods. The reaction of phenyl isocyanate (PhNCO) and butan-1-ol (BuOH) has been selected to describe the energetic and structural features of the catalyst-free urethane formation. The catalytic activities of DMHP, MSA, and TFMSA have been compared by adding them to the PhNCO-BuOH model system. The thermodynamic properties of the reactions were computed by using the G3MP2BHandHLYP composite method. It was revealed that in the presence of trifluoromethanesulfonic acid, the activation energy was the lowest within the studied set of catalysts. The achieved results indicate that acids can be successfully employed in urethane synthesis and the mechanism was described.

Design and development of UiO-67-coated PIM-1-based composites and demonstration of their detoxification performance

Polymer-supported MOF composites have emerged as versatile candidates for various separation and catalytic applications. In this study, we demonstrate design and development of UiO-67-coated Ce(OH)4@PIM-1 composites via dip-coating, drop-casting, solid-phase coating, and supramolecular assembly, and assess their preparation-structure-performance relations. The catalytic performance of the composites was investigated through hydrolysis of dimethyl 4-nitrophenyl phosphate (DMNP), as a nerve agent simulant. The findings revealed that while dip-coating method was unable to achieve a thick and uniform coverage of the MOF layer on the Ce(OH)4@PIM-1, the supramolecular assembly gave rise to 16 wt% MOF loading and the composite prepared via this method exhibited superior catalytic activity by achieving 100% DMNP conversion within 15 min with a half-time of ∼ 4 min at a rate of 0.165 min−1. The enhanced DMNP hydrolysis of the UiO-67-coated Ce(OH)4@PIM-1 composites prepared via supramolecular assembly was driven by the well-connected pore structure and well-dispersed MOF crystals, which enabled greater active sites accessibility. Post-characterization results confirmed that the materials retained their functionality after hydrolysis by exhibiting 100% DMNP conversion efficiency over three cycles. The findings of this study provide valuable insights into the development of advanced protective materials for defense and civilian applications.

Determinants of urinary dialkyl phosphate metabolites in midlife women: the Study of Women's Health Across the Nation Multi-Pollutant Study (SWAN-MPS).

Biomonitoring data and determinants of urinary dialkylphosphate (DAP) metabolites, markers of organophosphate pesticides, in racially diverse, non-occupationally exposed populations are scarce. This study evaluated urinary concentrations and potential determinants of DAP metabolites of organophosphate pesticides in a multi-site, multi-racial/ethnic cohort of women aged 45-56 years, the Study of Women's Health Across the Nation Multi-Pollutant Study (SWAN-MPS). We analyzed 963 urine samples collected in 1999-2000, the baseline of SWAN-MPS for longitudinal studies, and quantified DAP metabolites, including dimethyl alkylphosphates (DMAPs): dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP); and diethyl alkylphosphates (DEAPs): diethylphosphate (DEP), diethylthiophosphate (DETP), diethyldithiophosphate (DEDTP), using gas chromatography and triple quadrupole mass spectroscopy. Adjusted least squared geometric means (LSGMs) and 95% confidence intervals (CIs) were computed to compare DAP concentrations by socio-demographic, behavioral and dietary factors. The geometric means (geometric standard deviations) of total DAPs, DMAPs, and DEAPs were 141 (2.63) nmol/L, 102 (2.99) nmol/L, and 26.8 (2.46) nmol/L, respectively. Body mass index (BMI) was inversely associated with DMAPs and DEAPs: LSGM (95% CI) = 68.8 (55.7-84.9) and 21.0 (17.7-25.0) nmol/L for women with obesity vs. 102 (84.7-123) and 30.1 (25.7-35.1) nmol/L for women with normal/underweight, respectively. Fruit consumption was positively (74.9 (62.1-90.2) for less than 5-6 servings/week vs. 105 (84.8-130) nmol/L for 1 serving/day and more) whereas meat consumption was inversely associated with DMAPs (110 (95.0-128) for seldom vs. 82.3 (59.5-114) nmol/L for often consumption). Fresh apple consumption appears to be attributed to the DMAP differences. Alcohol consumption was positively associated with DEAPs (27.5 (23.1-32.7) for 2 drinks/week and more vs. 23.0 (20.0-26.6) nmol/L for less than 1 drink/month). Black women had higher concentrations of DEAPs compared with White women (27.3 (21.2-35.2) vs. 23.2 (20.2-26.7) nmol/L). Organophosphate pesticides (OPs) are synthetic chemicals and currently the most widely used type of insecticides. We examined multi-site, multi-ethnic cohort of midlife women in the U.S. that offers a unique opportunity to evaluate major determinants of OP exposure. We improved OP metabolite detection rates and obtained accurate concentrations using an improved analytical technique. Our findings suggest that consumptions of fruit, meat and alcohol are important determinants of OP exposure for midlife women. Higher concentrations of diethyl OP metabolites in Black women compared to White women, even after accounting for dietary intake, suggests additional, but unknown racial-ethnic differences that affect exposure.

Transesterification Induced Multifunctional Additives Enable High‐Performance Lithium Metal Batteries

AbstractThe electrolyte chemistry is crucially important for promoting the practical application of lithium metal batteries (LMBs). Here, we demonstrate for the first time that 1,3‐dimethylimidazolium dimethyl phosphate (DIDP) and trimethylsilyl trifluoroacetate (TMSF) can undergo in situ transesterification in carbonate electrolyte to generate dimethyl trimethylsilyl phosphate (DTMSP) and 1,3‐dimethylimidazolium trifluoroacetate (DITFA) as multifunctional additives for LMBs. H2O and HF can be removed by the Si−O group in DTMSP to improve the moisture resistance of electrolyte and the stability of cathode. Furthermore, the dissolution of lithium nitrate (LiNO3) in carbonate electrolyte can be promoted by the trifluoroacetate anion (TFA−) in DITFA, thereby optimizing the solvation structure and transport kinetics of Li+. More importantly, both DTMSP and DITFA tend to preferential redox decomposition due to the low lowest unoccupied molecular orbital (LUMO) and high highest occupied molecular orbital (HOMO). Consequently, a thin and robust layer rich in P/N/Si on the cathode and an inorganic‐rich layer (e.g. Li3N/Li3P) on the anode can be constructed and superior electrochemical performances are achieved. This artificial transesterification strategy to introduce favorable additives paves an efficient and ingenious route to high‐performance electrolyte for LMBs.

Transesterification Induced Multifunctional Additives Enable High-Performance Lithium Metal Batteries.

The electrolyte chemistry is crucially important for promoting the practical application of lithium metal batteries (LMBs). Here, we demonstrate for the first time that 1,3-dimethylimidazolium dimethyl phosphate (DIDP) and trimethylsilyl trifluoroacetate (TMSF) can undergo in situ transesterification in carbonate electrolyte to generate dimethyl trimethylsilyl phosphate (DTMSP) and 1,3-dimethylimidazolium trifluoroacetate (DITFA) as multifunctional additives for LMBs. H2O and HF can be removed by the Si-O group in DTMSP to improve the moisture resistance of electrolyte and the stability of cathode. Furthermore, the dissolution of lithium nitrate (LiNO3) in carbonate electrolyte can be promoted by the trifluoroacetate anion (TFA-) in DITFA, thereby optimizing the solvation structure and transport kinetics of Li+. More importantly, both DTMSP and DITFA tend to preferential redox decomposition due to the low lowest unoccupied molecular orbital (LUMO) and high highest occupied molecular orbital (HOMO). Consequently, a thin and robust layer rich in P/N/Si on the cathode and an inorganic-rich layer (e.g. Li3N/Li3P) on the anode can be constructed and superior electrochemical performances are achieved. This artificial transesterification strategy to introduce favorable additives paves an efficient and ingenious route to high-performance electrolyte for LMBs.