N-acetylcysteine and zinc sulphate abate di-2-ethylhexyl phthalate-mediated reproductive dysfunction in rats:Focus on oxidative and sex hormone receptors mechanisms

Objective:To investigate the potential of N-acetylcysteine(NAC)and zinc sulphate(ZnSO_(4))in mitigating reproductive dysfunction caused by di-2-ethylhexyl phthalate(DEHP)in rats and to understand the underlying mechanisms,specifically oxidative stress and sex hormone receptor activity.Methods:Thirty-five male Wistar rats were randomly divided into five equal groups(n=7 per group).Group 1 was administered 0.5 mL of distilled water and served as the control group.Group 2 was given only DEHP(750 mg/kg/day),while group 3,4 and 5 were given DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day),DEHP(750 mg/kg/day)plus ZnSO_(4)(0.5 mg/kg/day),and DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day)as well as ZnSO_(4)(0.5 mg/kg/day),respectively.All treatments lasted for 21 days.Samples were obtained after the rats were sacrificed,and hormones levels in the serum and markers of oxidative stress in the testicles were analyzed using the enzyme-linked immunosorbent assay.The amount of androgen receptors in the testicles was determined by immunohistochemistry,and the susceptibility of testosterone and DEHP to bind to androgen receptor and 5α-reductase was determined by molecular docking studies.Results:DEHP decreased reproductive hormones,testicular antioxidant enzymes,increased malondialdehyde levels,and negatively impacted histology of the pituitary and testes.NAC or ZnSO_(4) treatment showed a marked improvement in testicular antioxidant status and hormone levels,as well as a positive effect on the histology of the pituitary and testes.The combination of both treatments appeared to be more effective.The affinity of DEHP to bind to androgen receptors may lead to disruption of androgen receptor signaling,which can further result in dysfunction of hormones related to androgen.However,NAC is more likely to form stronger binding interactions with follicle stimulating hormone and luteinizing hormone receptors,as well as gonadotropin-releasing hormone receptors,when compared to DEHP.Conclusions:The possibility that NAC and ZnSO_(4) could downregulate DEHP-induced sex hormone changes is suggested by their potential to reduce toxicity.

Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate

The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine(4-HP) with tributyl phosphate(TBP), di(2-ethylhexyl) phosphoric acid(D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio(D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50-4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate(i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP,(ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA(1:1) and 4-HP:2D2EHPA(1:2) type complexes, while(iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA(1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

Green tea polyphenols alleviate di-(2-ethylhexyl)phthalate-induced liver injury in mice

BACKGROUND Di(2-ethylhexyl)phthalate(DEHP)is a common plasticizer known to cause liver injury.Green tea is reported to exert therapeutic effects on heavy metal exposureinduced organ damage.However,limited studies have examined the therapeutic effects of green tea polyphenols(GTPs)on DEHP-induced liver damage.AIM To evaluate the molecular mechanism underlying the therapeutic effects of GTPs on DEHP-induced liver damage.METHODS C57BL/6J mice were divided into the following five groups:Control,model[DEHP(1500 mg/kg bodyweight)],treatment[DEHP(1500 mg/kg bodyweight)+GTP(70 mg/kg bodyweight),oil,and GTP(70 mg/kg bodyweight)]groups.After 8 wk,the liver function,blood lipid profile,and liver histopathology were examined.Differentially expressed micro RNAs(miRNAs)and mRNAs in the liver tissues were examined using high-throughput sequencing.Additionally,functional enrichment analysis and immune infiltration prediction were performed.The miRNA-mRNA regulatory axis was elucidated using the starBase database.Protein expression was evaluated using immunohistochemistry.RESULTS GTPs alleviated DHEP-induced liver dysfunction,blood lipid dysregulation,fatty liver disease,liver fibrosis,and mitochondrial and endoplasmic reticulum lesions in mice.The infiltration of macrophages,mast cells,and natural killer cells varied between the model and treatment groups.mmu-miR-141-3p(a differentially expressed miRNA),Zcchc24(a differentially expressed mRNA),and Zcchc24(a differentially expressed protein)constituted the miRNA-mRNA-protein regulatory axis involved in mediating the therapeutic effects of GTPs on DEHP-induced liver damage in mice.CONCLUSION This study demonstrated that GTPs mitigate DEHP-induced liver dysfunction,blood lipid dysregulation,fatty liver disease,and partial liver fibrosis,and regulate immune cell infiltration.Additionally,an important miRNAmRNA-protein molecular regulatory axis involved in mediating the therapeutic effects of GTPs on DEHP-induced liver damage was elucidated.

Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-(2-ethylhexyl) phosphoric acid from sulfuric acid medium

The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.

Glycerin Monostearate Aggravates Male Reproductive Toxicity Caused by Di(2-ethylhexyl)Phthalate in Rats

Human beings are increasingly exposed to phthalates,which are a group of chemicals used to make plastics more flexible and harder to break,and simultaneously ingesting abundant food emulsifiers via daily diet.The purpose of this study was to investigate the effect of the food emulsifier glycerin monostearate(GMS)on male reproductive toxicity caused by di(2-ethylhexyl)phthalate(DEHP,one of the phthalates)and explore the underlying mechanism.Thirty male Sprague-Dawley rats were randomly divided into control group,DEHP group and DEHP+GMS group.Rats in the DEHP group and DEHP+GMS group were orally administered with 200 mg/kg/d DEHP with or without 20 mg/kg/d GMS.After 30 days of continuous intervention,it was found that the serum testosterone level was significantly lowered in DEHP group and DEHP+GMS group than that in control group(P<0.01).The serum testosterone level and the relative testis weight were significantly decreased in the DEHP+GMS group as compared with those in the DEHP group and control group(P<0.05).More spermatids were observed to be shed off in DEHP+GMS group than in DEHP group.The expression levels of cell cycle checkpoint kinase 1(Chkl),cell division cycle gene 2(Cdc2),and cyclin-dependent kinase 2(CDK2)were down-regulated in DEHP group,and this tendency was more significant in DEHP+GMS group(P<0.05 or P<0.01).There was no significant difference in the P-glycoprotein(P-gp)expression between DEHP group and control group.However,P-gp was markedly down-regulated in DEHP+GMS group(P<O.Ol).The results indicated that the food emulsifier GMS aggravated the toxicity of DEHP on male reproduction by inhibiting the cell cycle of testicular cells and the expression of P-gp in testis tissues.

Reactive extraction for intensifying 2-ethylhexyl acrylate synthesis using deep eutectic solvent [Im:2PTSA]

2-Ethylhexyl acrylate(2-EHA)is one of the most widely used acrylates in the polymer industry,which is synthesized via Fisher esterification that is limited by chemical equilibrium.To intensify the esterification process,in this work,reactive extraction concept is proposed,with halogen-free deep eutectic solvent(DES[Im:2PTSA])as dual solvent-catalyst that consists of imidazole(Im)and p-toluenesulfonamide(PTSA).The bifunctional effects of the DES[Im:2PTSA]are evaluated by thermodynamic analysis and experimental study.Favorable phase splitting is verified byσ-potential analysis predicted by COSMO-RS theory,combined with experiments,and the optimal acid-to-alcohol molar ratio is set to 1.2.The esterification kinetics is then experimentally determined and fitted using the molar-based and activity-based pseudo-homogeneous(PH)models,respectively.The activity-based PH model,that considers the bifunctional roles of the DES,proves to be more accurate with small RMSD of 0.0344.The stability of DES after recycling is validated to further confirm the industrial prospects of DES[Im:2PTSA]in 2-EHA production.

Synergistic extraction of praseodymium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline

The synergistic extraction of Pr^3＋ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester （P507, HL） and 8-Hydroxyquinoline （HQ） in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3＋ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3＋.

Solvent extraction equilibrium of dysprosium(Ⅲ) from nitric acid solutions with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester

In view of the importance of solvent extraction of rare earth metals with the acidic organophosphorous reagent,the development of a chemically based model applicable to high concentration is desired.In the present study,the equilibrium distribution of dysprosium(Ⅲ)between an aqueous nitric acid solution and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A)was measured in the range of an initial aqueous dysprosium(Ⅲ)concentration from 1.0×10-3to 1.0×10-1kmol/m 3and PC88A concentration from 0.16 to 0.65 kmol/m3in Shellsol D70 as the diluent.The obtained data were analyzed using the chemically based model in order to correlate the equilibrium distribution ratios.In this model,dysprosium(Ⅲ)was assumed to be extracted with the PC88A dimer as a 1:3 complex,the activities were considered for the aqueous species,and the effective concentration of the PC88A dimer was calculated using Alstad's empirical equation.As a result,the apparent extraction equilibrium constant was determined to be 253(kmol·m- 3)-2with an excellent correlation between the experiment and calculation results in the wide range of the logarithm of the distribution ratio from-2 to 3.5.In conclusion,the methodology in this model would be effective for quantitative description of solvent extraction behavior of general rare earth elements as well as dysprosium.

Synthesis of Highly-Selective Fibrous Adsorbent by Introducing 2-Ethylhexyl Hydrogen-2-Ethylhexylphosphonate for Scandium Adsorption

2-ethylhexyl hydrogen-2-ethylhexylphosphonate (EHEP) is commonly used as a metal extractant because it has a particular affinity for rare-earth metals like Scandium (Sc). To develop a highly-selective adsorbent of Sc(III), EHEP was introduced as a functional group onto a polyethylene fabric with radiation-induced graft polymerization(RIGP). The adsorption performances for Sc(III) were evaluated with aqueous solutions containing Sc(III) and Fe(III) in bath and column tests. As a result of column test, the adsorption capacities of Sc(III) and Fe(III) until the bed volume reached 5000 were 5.22 and 0.12 mg/g, respectively. It means that the amount of collected Sc(III) by the EHEP adsorbent was approximately 44 times higher than that of Fe(III). These results indicate that the grafted adsorbent containing EHEP has an extremely high selectivity for Sc(III) adsorption.

THE EXTRACTED COMPLEX FORMED BY MONO (2-ETHYLHEXYL)-2-ETHYLHEXYL PHOSPHATE WITH DIVALENT Mn

In order to clarify the mechanism and the complex formed in the extraction of divalent Mn by alkylphosphonic acid monoester, the solid complex has been prepared by mono (2-ethylhexyl)-2-ethylhexyl phosphate, HEH(EH)P, HA with divalent Mn. The elemental analysis, magnetic susceptibility and thermogravimetry have been determined for the solid complex of HEH(EH)P-Mn(II) and the infrared spectrum has been carried out in comparison to the extractant HEH(EH)P. The extracted compound has also been studied by electronic and electron spin resonance spectroscopy in octane solvent and solid state at room temperature. On the basis of the measurements, it is concluded that the structure of the solid polymeric species MnA_2 is in a tetrahedral arrangement.

Urine Metabonomic Analysis of Interventions Effect of Soy Isoflavones on Rats Exposed to Di-(2-ethylhexyl) Phthalate

Objective Di-(2-ethylhexyl) phthalate(DEHP) is a ubiquitous environmental contaminant.As an endocrine disruptor,it seriously threatens human health and ecological environmental safety.This study examines the impact of intervention with soybean isoflavones(SIF) on DEHP-induced toxicity using a metabonomics approach.Methods Rats were randomly divided into control(H),SIF-treated(A,86 mg/kg body weight),DEHP-treated(B,68 mg/kg),and SIF plus DEHP-treated(D) groups.Rats were given SIF and DEHP daily through diet and gavage,respectively.After 30 d of treatment,rat urine was tested using UPLC/MS with multivariate analysis.Metabolic changes were also evaluated using biochemical assays.Results Metabolomics analyses revealed that p-cresol glucuronide,methyl hippuric acid,N1-methyl-2-pyridone-5-carboxamide,lysophosphatidycholine [18:2(9 Z,12 Z)] {lyso PC [18:2(9 Z,12 Z)]},lyso PC(16:0),xanthosine,undecanedioic acid,and N6-acetyl-l-lysine were present at significantly different levels in control and treatment groups.Conclusion SIF supplementation partially protects rats from DEHP-induced metabolic abnormalities by regulating fatty acid metabolism,antioxidant defense system,amino acid metabolism,and is also involved in the protection of mitochondria.

Structure Reactivity Studies on the Extraction of Rare Earths by Di(2-ethylhexyl)chloroalkyl Phosphonates

The extractive separation properties and the extractive regularity of the lanthanide elements by five di(2-ethylhexyl)alkyl phosphonates with various alkyl structure:di(2-ethylhexyl)chloromethyl phosphonate CH_2ClP(O) (OC_8H_(17)-i)_2(1),di(2-ethylhexyl)β-chloroethyl phosphonate ClCH_2CH_2P(O) (OC_8H_(17)-i)_2 (2),di(2-ethylhexyl)α-chloroethyl phosphonate CH_3CHClP(O)(OC_8H_(17)-i)_2 (3),and corresponding di(2-ethylhexyl)methyl phosphonate CH_3P(O)(OC_8H_(17)-i)_2 (4),di(2-ethylhexyl)ethyl phosphonate C_2H_5P(O) (OC_8H_(17)-i)_2 (5),in nitrate system have been studied.The coordination compounds were prepared. The structure of these extractants and their coordination compounds were further explored by IR and ^(31)P NMR spectra.

Synthesis and Performances of Poly(2-ethylhexyl acrylate-co-acrylic acid) Used for Warp Sizing

A series of poly （ 2-ethylhexyl acrylate-co-acrylic acid ） s （ P （2-EHA-co-AA） ）s with different mole contents of 2-ethylhexyl acrylate （ 2-EHA ） were synthesized through free radical copolymerization in ethanol for investigating the influences of copolymer composition upon the performance such as apparent viscosity, film behaviors, and adhesion to fibers for warp sizing. The content of 2-EHA was varied from 80 % to 40 %. The adhesion was estimated by measuring tensile strength and work-to-break of impregnated roving. The film behaviors were evaluated in terms of breaking strength, breaking elongation, work-to-break, and flex- fatigue resistance. It was observed that the viscosity, adhesion, and film behaviors of the copolymers strongly depended on the content of 2-EHA. Excessively increasing or decreasing the content of 2-EHA units incorporated into the copolymeric chains reduces the serviceability of P（2-EHA-co-AA） in warp sizing. The adhesion and film behaviors of the copolymcr reach their maximal values at mole content of 50 % simultaneously. Therefore, the copolymer used as sizing agent should be synthesized under equal mole of 2-EHA and AA in monomer formulation.

Impairment of Di(2-Ethylhexyl) Phthalate on Cellular Immunity in Kunming Mice

Immunity is crucial to the health of animals and it can determine their survival and fitness. Di(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer and hence is the most abundant phthalate in the environment. Exposure to DEHP is of great concern for human health. In the present study, we tested the hypothesis that exposure to DEHP would suppress T cell-mediated immunity in mice. Twenty adult male Kunming mice were randomly assigned into the control (n = 10) and the DEHP treatment (n = 10) groups. Both groups have free access to food and water, while the mice in the latter group drank DEHP solution (2000 mg/L) for 42 days. T cell-mediated immunity assessed by phytohaemagglutinin (PHA) response was depressed in the DEHP treated mice compared with the controls, however, wet thymus and spleen mass, white blood cells were not influenced by DEHP treatment. Taken together, different immunological parameters responded differently to DEHP treatment in Kunming mice.

Spectral Properties and Solubilization Location of 2′-Ethylhexyl 4-（N,N-Dimethylamino）benzoate in Micelles

Dual fluorescence and UV absorption of 2′-ethylhexyl 4-（N,N-dimethylamino）benzoate （EHDMAB） were investigated in cationic, non-ionic and anionic micelles. When EHDMAB was solubilized in different micelles, the UV absorption of EHDMAB was enhanced. Twisted intramolecular charge transfer （TICT） emission with longer wavelength was observed in ionic micelles, whereas TICT emission with shorter wavelength was obtained in non-ionic micelles. In particular, dual fluorescence of EHDMAB was significantly quenched by the positively charged pyridinium ions arranged in the Stern layer of cationic micelles. UV radiation absorbed mainly decays via TICT emission and radiationless deactivation. The dimethylamino group of EHDMAB experiences different polar environments in ionic and non-ionic micelles according to the polarity dependence of TICT emission of EHDMAB in organic solvents. In terms of the molecular structures and sizes of EHDMAB and surfactants, each individual EHDMAB molecule should be buried in micelles with its dimethylamino group toward the polar head groups of different micelles and with its 2′-ethylhexyl chain toward the hydrophobic micellar core. Dynamic fluorescence quenching measurements of EHDMAB provide further support for the location of EHDMAB in different micelles.

Adsorption by Liquid-Liquid Extraction of Hg(II) from Aqueous Solutions Using the 2-Butyl-imidazolium Di-(2-ethylhexyl) Phosphate as Ionic Liquid

In this work, a novel room temperature ionic liquid (2-butyl-imidazolium di-(2-ethylhexyl) phosphate) ([C4mim] [D2EHPA]) was synthesized and tested as extractant in the mercury(II) liquid-liquid extraction. The effects of parameters such as aqueous to organic phase’s volume ratio, metal concentration IL concentration, pH levels, ionic strength, and temperature were reported. For the extraction of metal, [C4mim]3[R.HR]3[HgCl2]org and [C4mim]3[R.HR]3 [HgClOH]org species were formed where (H2R2) was D2EHPA. In the case of ionic strength, the results showed that the addition of sodium acetate at 0.302 mmol·L?1 to the aqueous phase strongly increased the mercury extraction yield (R = 100%). The extracted species were investigated by a calculation program using CHEAQS V. L20.1 inorder to determine the relation between the percentages of the extracted species and the extraction yield. The results showed that the extracted species in the best conditions were HgCl2 and HgClOH with respective percentages 80.66% and 18.29%.

Reducing children’s exposure to di(2-ethylhexyl)phthalate in homes and kindergartens in China:Impact on lifetime cancer risks and burden of disease

Exposure to di(2-ethylhexyl)phthalate(DEHP)in the indoor environment has been linked with significant health risks for Chinese children.Multi-phase DEHP concentrations in Chinese residences and kindergartens were estimated using a mass balance model based on the current baseline condition and control strategies(i.e.,increasing ventilation rate,reducing area of sources,using mechanical ventilation systems,and using portable air cleaners).The health benefits of each control strategy were quantified as the reduction in lifetime cancer risks(LCR)and burden of disease(BoD).In the current situation,the mean LCR and disability-adjusted life years(DALY)number attributable to indoor DEHP exposure for Chinese children were around 6.0×10^(−6) and 155 thousand,respectively.The mean LCR and DALY might be reduced by 25%-54%and 16%-40%,respectively,by increasing air exchange rates by 100%,reducing the use of source materials by two-thirds or deploying commercial air cleaners in naturally ventilated buildings.Meanwhile,avoidable DALYs could result in a reduction of mean economic losses of 2.2-5.3 billion RMB.Mechanical ventilation systems with filtration units may not be helpful for reducing children’s health risks.House-specific and tailor-made control measures are critical in lowering indoor exposure to DEHP to promote sustainable buildings and children’s health in China.

Maslinic acid supplementation prevents di(2-ethylhexyl)phthalate-induced apoptosis via PRDX6 in peritubular myoid cells of Chinese forest musk deer

Chinese forest musk deer(FMD),an endangered species,have exhibited low reproductive rates even in captivity due to stress conditions.Investigation revealed the presence of di(2-ethylhexyl)phthalate(DEHP),an environmental endocrine disruptor,in the serum and skin of captive FMDs.Feeding FMDs with maslinic acid(MA)has been observed to alleviate the stress response and improve reproductive rates,although the precise molecular mechanisms remain unclear.Therefore,this study aims to investigate the molecular mechanisms underlying the alleviation of DEHP-induced oxidative stress and cell apoptosis in primary peritubular myoid cells(PMCs)through MA intake.Primary PMCs were isolated and exposed to DEHP in vitro.The results demonstrated that DEHP significantly suppressed antioxidant levels and promoted cell apoptosis in primary PMCs.Moreover,interfering with the expression of PRDX6 was found to induce excessive reactive oxygen species(ROS)production and cell apoptosis in primary PMCs.Supplementation with MA significantly upregulated the expression of PRDX6,thereby attenuating DEHP-induced oxidative stress and cell apoptosis in primary PMCs.These findings provide a theoretical foundation for mitigating stress levels and enhancing reproductive capacity of in captive FMDs.

An Estimation of the Daily Intake of Di(2-ethlhexyl) Phthalate(DEHP) among Workers in Flavoring Factories

Objective To estimate the daily intake of DEHP among workers in flavoring factories. Methods 71 workers in two flavoring manufacturers, 27 administrators in those factories and 31 laboratory technicians in a research institute were recruited and assigned to exposure group, control group 1 and control group 2 respectively. Their urinary DEHP metabolites, mono（2-ethylhexyl） phthalate （MEHP）, mono-（2-ethyl-5-hydroxyhexyl） phthalate （MEHHP）, mono-（2-ethyl-5-oxohexyl） phthalate （MEOHP）, were detected by isotope dilution-ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）. The urinary metabolites concentrations were converted into DEHP intake levels using two pharmacokinetic models： the urine creatinine-excretion （UCE） one and the urine volume （UV） one. Results No significant differences were found among the three groups. Based on the urinary concentrations of Z3MEHP, we got a median daily DEHP intake of 3.22 or 1.85 μg/kg body-weight/day applying the UV or UCE models respectively. Depending on the UV model, three subjects （2.34%） exceeded the RfD value given by US EPA and the P50 of estimate daily DEHP intakes accounted for 16.10% of the RfD value. No subjects exceeded the limitation depending on the UCE model. Conclusion The workers in flavoring factories were not supposed to be the high DEHP exposure ones and their exposure level remained at a low risk.

Tb(III) Transport in Dispersion Supported Liquid Membrane System with D2EHPA as Carrier in Kerosene

The transport of Tb（III） in dispersion supported liquid membrane（DSLM） with polyvinylidene fluoride membrane（PVDF） as the support and dispersion solution including HCl solution as the stripping solution and di（2-ethylhexyl） phosphoric acid（D2EHPA） dissolved in kerosene as the membrane solution, has been studied. The effects of pH value, initial concentration of Tb（III） and different ionic strength in the feed phase, volume ratio of membrane solution to stripping solution, concentration of HCl solution, concentration of carrier, different stripping agents in the dispersion phase on the transport of Tb（III） have also been investigated, respectively. As a result, the optimum transport conditions of Tb（III） were obtained, i.e., the concentration of HCl solution was 4.0 mol/L, the concentration of D2EHPA was 0.16 mol/L, the volume ratio of membrane solution to stripping solution was 30：30 in the dispersion phase and pH value was 4.5 in the feed phase. Ionic strength had no obvious effect on the transport of Tb（III）. Under the optimum conditions, the transport percentage of Tb（III） was up to 96.1% in a transport time of 35 min when the initial concentration of Tb（IIl） was 1.0× 10 -4 mol/L. The diffusion coefficient of Tb（III） in the membrane and the thickness of diffusion layer between feed phase and membrane phase were obtained and the values were 1.82×10 -8 m2/s and 5.61 um, respectively. The calculated results were in good agreement with the literature data.