Showing papers on "Dibutyl phthalate published in 2001"

Effects of phthalate esters on the developing reproductive tract of male rats

Abstract: Phthalate esters are a large group of chemical agents used predominantly as plasticizers and solvents. Certain members of this chemical class have been shown to cause reproductive and developmental toxicity. Recent attention has focused on the potential of these agents to interfere with male reproductive development through a postulated antiandrogenic mechanism. Observations have focused on di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP) and butyl benzylphthalate, with most information relating to dose-response relationships obtained for DBP. Neither DBP, DEHP nor their major metabolites interacted with human or rodent androgen receptors (AR) in transcriptional activation assays. DBP was administered during the critical window of development of the male reproductive system, after which the resulting offspring were examined until adulthood. DBP elicited marked effects on the developing male reproductive tract, including malformations of the epididymis and vas deferens, and hypospadias. Retention of thoracic nipples/areolae and reductions in anogenital distance were also noted. Surprisingly, Leydig cell adenomas were induced in some male offspring at 100 days of age. All these events occurred in the absence of any toxicity in the pregnant dam. Examination of testes from fetal rats indicated markedly reduced testosterone levels and increased Leydig cell numbers after DBP administration to the dams. Leydig cells were positive for AR and 3-betahydroxysteroid dehydrogenase.

A biomarker approach to measuring human dietary exposure to certain phthalate diesters

Abstract: Three groups of eight volunteers were administered stable isotope-labelled phthalate diesters in a single dose and the amount of the corresponding phthalate monoesters excreted in the urine was measured. Amongst the phthalates administered were the symmetrical dibutyl-, di-2-ethyl- and diisooctyl- phthalates along with the unsymmetrical benzylbutylphthalate. The control group received no dose, the low dose group received 168-255 microg of each phthalate and the high dose group received 336 to 510 microg of each phthalate. The excreted phthalate monoesters were measured by LC-MS following hydrolysis of conjugates. The bulk of phthalate monoester was excreted in the first 24 hour period following the dose. For dibutylphthalate, 64% and 73% on a mole basis of the low, and high dose respectively was excreted as monobutylphthalate. For dioctylphthalate (sum of the 2-ethylhexyl and the isooctyl species) the yield was 14 and 12% of the low and high dose excreted as monooctylphthalate. For benzylbutylphthalate, 67% and 78% was eliminated as monobenzylphthalate and only 6% (measured for the high dose only) was eliminated as monobutylphthalate. These conversion factors can be used in future studies to assess exposure to phthalate esters via measuring urinary levels of the monoester metabolites.

Degradation of dibutyl phthalate by homogeneous photocatalysis with Fe(III) in aqueous solution

Abstract: The degradation of dibutyl phthalate (DBP) photoinduced by Fe(III) in aqueous solution has been investigated under monochromatic irradiation and sunlight. Hydroxyl radicals OH, responsible of the degradation, are formed via an intramolecular photoredox process in excited Fe(III) aquacomplexes. The concentration in Fe(OH)2+ in the starting Fe(III) solution appears to be a controlling parameter of the degradation rate, as already stated in our previous works. The first step of the decomposition of DBP involves the hydrogen abstraction on the butyl chain mainly on the carbon in α-position to aromatic ring. The major primary photoproducts are hydroxy, dihydroxy and carboxylic derivatives. For prolonged irradiations, DBP and its photoproducts are completely mineralized due to the regeneration of the absorbing species and the continuous formation of OH radicals that confers a catalytic aspect to the process. Consequently, the degradation photoinduced by Fe(III) could be an efficient method of DBP removal from water.

Determination of phthalates in crude extracts of sewage sludges by high-resolution capillary gas chromatography with mass spectrometric detection.

Abstract: A simple solvent extraction by ethyl acetate without subsequent cleanup was used to determine 16 phthalic acid esters (PAEs), including bis(2-ethylhexyl) phthalate (DEHP), in sewage sludge samples from different catchment areas. The compounds were separated on a gas chromatographic capillary column with a nonpolar HT-8 stationary phase. For most of the PAEs, internal standard quantification with deuterated dibutyl phthalate (DBP) and deuterated DEHP was best achieved by using electron ionization mass spectrometry in the selected-ion monitoring mode. Because of its high concentrations in the sludges, DEHP was quantified in the full-scan acquisition mode. Molecular weight and ester-type information for the PAEs was obtained in the positive chemical ionization mode with methane as the reagent gas. Finally, selected sewage sludges containing different amounts of industrial wastewater were analyzed by the proposed method. DEHP was the most abundant compound found at 21-114 mg/kg x dm, followed by the lower-molecular weight PAEs diethyl phthalate, diisobutyl phthalate, and DBP and the higher-molecular weight compounds butylbenzyl phthalate, dicyclohexyl phthalate, di-n-octyl phthalate, and dinonyl phthalate, which were present mostly at <1 mg/kg x dm.

Effects of Mono‐n‐butyl Phthalate on the Development of Rat Embryos: In vivo and in vitro Observations

Abstract: The present study was conducted to further characterize the embryotoxic effects mono-n-butyl phthalate, a major metabolite of the plasticizer di-n-butyl phthalate, and evaluate its role in the developmental toxicity of di-n-butyl phthalate. The embryotoxic effects of mono-n-butyl phthalate were compared to those of the parent compound di-n-butyl phthalate after a single oral administration of 1.8, 3.6, 5.4, or 7.2 mmol/kg di-n-butyl phthalate or mono-n-butyl phthalate to Sprague-Dawley rats on gestational day 10 (Day 10). Embryos were evaluated for growth and development on Day 12. Both chemicals induced concentration-dependent developmental toxicity (i.e. decreased growth and malformations) which became apparent at 3.6 mmol/kg. Di-n-butyl phthalate and mono-n-butyl phthalate were approximately equally potent and produced qualitatively similar dysmorphogenic effects. Macroscopically, the most common malformations involved the prosencephalon, the optic system, and the mandibular and maxillary processes. In addition, the embryotoxic potential of mono-n-butyl phthalate was evaluated in vitro using the rat whole embryo culture system. Day 10 embryos were cultured for 48 hr in the presence of 0.5 to 5 mM mono-n-butyl phthalate and were then evaluated as the embryos grown in utero. Mono-n-butyl phthalate was a potent direct acting embryotoxicant, causing concentration-related growth retardation and dysmorphogenesis. The spectrum of morphological defects observed in mono-n-butyl phthalate-exposed embryos in vitro was comparable to those seen in vivo in the embryos at the same developmental stage after maternal administration of di-n-butyl phthalate or mono-n-butyl phthalate. These data provide additional evidence in support of the hypothesis that mono-n-butyl phthalate may be the active species for the developmental toxicity of ingested di-n-butyl phthalate in rats.

Effects of di(2-ethylhexyl) phthalate and dibutyl phthalate on the collembolan Folsomia fimetaria

Abstract: Lethal and sublethal effects of di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) on adult individuals of the collembolan Folsomia fimetaria were investigated in the laboratory by the use of small microcosms. Effects of DEHP and DBP were also tested on newly hatched collembolans in a multidish system. The endpoints were juvenile mortality, growth, and development. When exposed to DEHP, adults and juveniles were unaffected at all test concentrations, that is, up to 5,000 mg/kg. However, DBP caused increased adult mortality at 250 mg/kg and juvenile mortality at 25 mg/kg. For DBP, adult reproduction was a more sensitive endpoint than was survival, with an EC10 and EC50 of 14 and 68 mg/kg, respectively. Juvenile molting frequency seems to be a sensitive parameter, because number of cuticles produced by young springtails was reduced at 1 mg/kg. Toxicity was reduced when soil spiked with DBP was stored at 20°C for a period of up to 28 d before adding the animals. Reduction in toxicity of DBP may be due a combination of degradation, evaporation, and adsorption of DBP to soil material. This was confirmed by chemical analyses, which showed a rapid initial disappearance followed by a much slower disappearance. Our results lead to the overall conclusion that significant adverse effects of phthalates on collembolans are not likely to occur as a result of normal sewage sludge application.

調理用pvc製手袋使用規制後における市販弁当中のフタル酸エステル類及びアジピン酸ジ(2-エチルヘキシル)濃度

Abstract: Ten samples of retail packed lunches purchased from convenience stores were determined for 11 phthalates and di(2-ethylhexyl) adipate (DEHA) in August 2000, 2 months after the prohibition of DEHP-containing PVC gloves in Japan. Each homogenized sample was extracted with acetonitrile, partitioned with n-hexane, and cleaned up using Florisil and PSA columns. Phthalates in the extract were determined by GC/MS (SIM). The limits of detection were 14.9 ng/g for di(2-ethylhexyl) phthalate (DEHP) and 18.6 ng/g for dibutyl phthalate (DBP). Levels of phthalates in packed lunch samples were 45 to 517 ng DEHP/g (198 ng/g, average), ND to 90 ng DEHA/g, and ND to 10.0 ng BBP/g. Diisononyl phthalate (DINP) was detected in one sample at 76 ng/g. Average DEHP level in ten samples was 4% of that in 1999. The contents of other phthalates were also reduced. DBP was not detected in any sample. Recovery of deuterated isomers added as surrogates was 27.9% for DNP-d4, and 40.6 to 101.5% for the other phthalates.

Phthalate esters influence FGF-2 translocation in Py1a rat osteoblasts.

Abstract: Exposure of the Py1a rat osteoblastic cells to butyl benzyl phthalate (BBP) and dibutyl phthalate (DBP) showed that these endocrine disrupting chemicals (EDC) strongly and reversibly affect the cytoplasmic fibroblast growth factor-2 (FGF-2) translocation into the nucleus in a dose-dependent and time-related manner. Stimulation of cells with high concentrations of BBP or DBP for short timing gave results comparable to those of cells treated with low concentrations for long timing. By confocal laser scanning microscope (CLSM) analysis it was found that the first relevant effect resulted in an accumulation of FGF-2 near the nuclear envelope, sometimes in the shape of clusters; the growth factor was then translocated into the nucleus and, finally, after long periods of exposure, the basal nuclear and cytoplasmic binding, typical of unstimulated cells, was re-established. In addition it was found that phthalate esters did not affect the FGF receptor 2 (FGFR-2) but decreased Con A binding indicating a possible inhibition of collagen fiber assembly. The different concentrations and timing of exposure of BBP and DBP affected the FGF-2 modulation in a similar way. Noticeable cumulative effects of BBP and DBP were not observed.

Liquid + Liquid Equilibrium in the Ternary Systems Water + Ethanol + Dialkyl Phthalate (Dimethyl, Diethyl, and Dibutyl Phthalate) at 298.15 K

Abstract: Liquid + liquid equilibrium was determined for three ternary systems water + ethanol + dialkyl phthalates (dimethyl, diethyl, and dibutyl phthalate) at 298.15 K. The turbidimetry titration method was used to obtain the binodal curves. Direct analytical methods were used to determine the composition of coexisting phases. The critical point composition was extrapolated from equilibrium data for each of the ternary systems using the Coolidge method. Excess enthalpy data were obtained for the system dimethyl phthalate + ethanol at 298.15 K. These, along with ternary and literature binary data, allowed a thorough thermodynamic description of the system water + ethanol + dimethyl phthalate. The modified Wilson equation was employed for this purpose.

Degradation of Dibutyl Phthalate in Water by the Aid of Metals under γ-Ray Irradiation

Abstract: The degradation of dibutyl phthalate (DBP), one of endocrine disruptors, by γ-ray irradiation was enhanced by the effective energy conversion of γ-ray through the interaction with some kind of metal materials.

Structure and characterization of poly[(vinylidene fluoride)-co-hexafluoropropene]–(dibutyl phthalate) blends

Abstract: Blends of poly[(vinylidene fluoride)-co-hexafluoropropene] with dibutyl phthalate were examined by wide- and small-angle X-ray scattering, differential scanning calorimetry and dynamic mechanical spectroscopy, in order to study the influence of amount of plasticizer and the crystallization rate on the crystallinity and lamellar morphology of the copolymer. The dibutyl phthalate seems, at least for the cooling and heating rates used, simply to dilute the crystalline phase without affecting the amount of polymer that is able to crystallize. Furthermore, the small-angle X-ray scattering technique points out that the plasticizer mostly enters the amorphous phase either outside or inside the lamellar stacks. © 2001 Society of Chemical Industry

Effect of Dibutyl Phthalate on Demodicidosis

Abstract: Objective To evaluate the curative effect and safety of dibutyl phthalate on demodicidosis. Methods A single blinded and controlled study of human demodicidosis treated with dibutyl phthalate was conducted. One hundred and forty three patients with demodicidosis, including 81 acne and 62 rosacea, randomly divided into trial and control groups. The trial group was treated with dibutyl phthalate and control group with "new fumanling" cream twice a day in the early morning and evening respectively for six weeks consecutively. Results The rates of excellent, good, and fair efficacy and total effective rate in the trial group with acne were 53\^7%, 41\^5%, 4\^9% and 100% respectively, with a significant difference to the control group (P0\^05). The rates in the trial group with rosacea were 40\^6%, 40\^6%, 18\^8% and 100% respectively, with no statistical difference to the control group (P0\^05). No complaint of side effects in the trial group was recorded. Conclusion Dibutyl phthalate is highly effective to demodicidosis without prominent adverse reactions.

A TiO2-Suspended Continuous Flow Photoreactor System Combined with the Separation of TiO2 Particles by Coagulation for the Photocatalytic Degradation of Dibutyl Phthalate

Abstract: A TiO2-suspended continuous flow photoreactor system combined with the separation of TiO2 particles by coagulation was applied for the photocatalytic degradation of dibutyl phthalate (DBP). The system enabled the efficient degradation of DBP and the continuous discharge of transparent water.

Kinetic Study on Phthalates

Abstract: To assess the thermal stability of phthalates a flow reactor with a jet nozzle was developed by the authors. Thermal decomposition reactions of phthalates, each having a high boiling point and viscosity, were conducted with this reactor for a short period from 2.4∼8.4 s. The phthalate were found from the results to decompose by cis elimination into the usual esters at 250∼500°C. Assuming first order reactions, activation energy determined when using a fixed quantity of unreacted phthalate was found to be as follows; dibutyl phthalate, 22.4; dihexyl phthalate, 38.4; dioctyl phthalate, 45.0; di(2-ethylhexyl) phthalate, 40.6; didecyl phthalate, 35.4; and dilaulyl phthalate, 24.2 kcal/mol.

Phthalate esters in marine algae

Abstract: o-Phthalate esters as diethyl phthalate, dibutyl phthalate, di-isobutyl phthalate and diethylhexyl phthalate were identified at surface and inner part of algae collected in the Bosphorus, as Ulva lactuca, Enteromorpha linza, Cystoseria barbata, Pterocladia capillaceaeand Ceramium rubrum. The same esters were also detected in seawater samples taken from the same area. Thus parallelism in pollution was noted between the algae and the surrounding seawater,

Water-soluble liquid adhesive for locating and its praparing process

Abstract: A water-soluble liquid adhesive for locating is prepared from methyl methacrylate graft latex (35-45%), ethylene/ethyl acrylate/ethylene acetate copolymer emulsion (17-23%), casein (4-6%), zinc oxide(12%), low-grade alcohol (2%), dibutyl phthalate (05%), antiageing agent, etc through mixing said latex with emulsion, adding casein and antiageing agent, dissolving in solution dibutyl phthalate, adding alcohol and butanol, stirring, cooling, stirring, regulating pH value and filtering to obtain white emulsion

Extraction of plasticizer from electrochemical cells

Abstract: A method for removing plasticizers such as dibutyl phthalate from an electrode / current collector assembly or from the anode, cathode, and separator components of an electrochemical cell precursor using an extraction solvent that includes an aliphatic alcohol selected from the group consisting of ethanol, butanol, pentanol and propanol and mixtures thereof. Most preferably the extraction solvent is isopropanol. Ultrasound waves can also be employed to significantly reduce the extraction time.

Attractive activity to natural enemies and component analysis of the rinses from tea aphid body surface

Abstract: With behaviour bioassay and electroantennogram investigation,it is found that both n-hexane and ether rinses from tea aphid body surface showed obvious attractive activity to its important natural enemies Aphidius sp., Chrysopa sinica, and Coccinella septempunctata and the attractive activity of n-hexane rinse was slight stronger. GC and GC-MS analyses showed that the main components in n-hexane rinse were undecane, benzaldehyde, 2,5-hexanedione, 2,5-dihydro-thiophene, linallol, naphthalene, 4-methyl -octane, 1,2-benzenedicarboxylic acid, bis (dibutyl phthalate), dibutyl phthalate and eicosane, in which the amounts of benzaldehyde, 2,5-hexanedione and linalool were a little more than the others. The main components from ether rinse were E-2-hexenoic acid, heptadecane, 2,6,10,14-tetramethyl-pentadecane, eicosane, tetratetracontane, dibutyl phthalate and nonadecane, among which the amounts of E-2-hexenoic acid and heptadecane were much more.

Phthalate의 피부자극시험 및 안점막자극시험에 관한 연구

Abstract: Phthalates are widely used as plasticizers to impart softness and flexibility to normally rigid polyvinylchloride products. However, there are not much studies for dermal and ocular irritation toxicity of phthalates. So we investigated the skin or eye irritation effect of some phthalates which was not reported. The primary skin irritation of diethyl phthalate (DEP), diisodecyl phthalate (DIDP) , diisononyl phthalate (DINP), dipropyl phthalate (DPP) and dipropyl phthalate (DPrP) was studied. The ocular irritation of dibutyl phthalate(DBP), DIDP, DINP, DPP and DPrP was also studied. DEP, DIDP, DINP, DPR, and DPrP were found to be non-irritating to the skin of the test animals. DBP, DIDP, DINP and DPP were found to be non-irritating to the eye of the rabbits. DPrP caused the slight irritations to the eye in 1 or 2 days after treatment but irritation of the animals was soon recovered.

Coagulant for repair load base and its use method

Abstract: The coagulant consists of epoxy resin, dibutyl phthalate and ethylenediamine in the weight ratio of 100 to 15-25 to 8-12. When the coagulant is used, one soil ring around the crack in load base is first formed, epoxy resin is heated to melt and mixed with dibutyl phthalate; and after the mixture liquid is cooled to below 40 deg.c and further mixed with ethylenediamine, the second mixture is injected into the area inside the soil ring so that the coagulant combines with the concrete in high strength.

Protecting agent for preventing infection of schistosomiasis

Abstract: A protecting agent for preventing infection of schistosomiasis contains base oil extractd from curcas tree seeds, benzyl benzoate (5-10 wt.%), dibutyl phthalate (3-5) and alcohol (3-5). Its advantages are low toxic by-effect and high effect.