Dibutyl Phtalate Research Articles

Phthalic acid esters content in yoghurt with chia flour and bamboo fiber during storage time

Phthalic acid esters are plasticizers, they can migrate freely from plastic to their surroundings. They have negative health effects. European legislation sets specific migration limits for phthalic acid esters. In our study, we deal with two esters of phthalic acid, dibutylphtalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP). It was studied the effect of storage of four types of yoghurt on the concentration of phthalic acid esters. Yoghurts contained 1% chia flour, 5% chia flour, 1% bamboo fiber and 5% bamboo fiber. Yoghurts were stored in plastic cups, which contained both examined phthalic acid esters. Esters of phthalic acid were determined after 1 week of storage then after 2 weeks of storage and in the original raw material. Furthermore, the pH of the yoghurt was determined. The pH values ”‹”‹were correlated with phthalate concentrations: the correlation coefficient for DBP with a pH of -0.0265 and for DEHP with a pH of 0.3075. Mean concentrations of DEHP decreased over time, while DBP decreased for yoghurt with 1% chia flour, while in other cases they increased. The mean DBP concentrations in yoghurt were higher than the average concentrations of DEHP. Comparing the mean sample values ”‹”‹with t-test for dependent samples for yoghurt of the same type, when comparing the DBP or DEHP concentration in week 1 with the DBP or DEHP concentration at week 2, the mean values ”‹”‹were consistent. It can be noted that there was no increase in DEHP concentrations from cups to yoghurts, which was probably due to a lower concentration in cups than the DBP concentration. DBP concentrations increased in 3 of the 4 types of yoghurt. The determined pH in yoghurts did not differ significantly. Apparently a greater effect on the migration of phthalic acid esters will have in our case a different yoghurt consistency than pH. It would be appropriate to examine the effect of food density on the migration of phthalic acid esters. Likewise, it would be appropriate to examine the effect of pH but in the same food with different pH on the migration of phthalic acid esters.

Pressurized liquid extraction-gas chromatography-mass spectrometry analysis of fragrance allergens, musks, phthalates and preservatives in baby wipes

Baby wipes and wet toilet paper are specific hygiene care daily products used on newborn and children skin. These products may contain complexes mixtures of harmful chemicals. A method based on pressurized liquid extraction (PLE) followed by gas chromatography-mass spectrometry (GC-MS) has been developed for the simultaneous determination of sixty-five chemical compounds (fragrance allergens, preservatives, musks, and phthalates) in wipes and wet toilet paper for children. These compounds are legislated in Europe according Regulation EC No 1223/2009, being twelve of them banned for their use in cosmetics, and one of them, 3-iodo-2-propynyl butylcarbamate (IPBC), is banned in products intended for children under 3 years. Also, propyl-, and butylparaben will be prohibited in leave-on cosmetic products designed for application on the nappy area of children under 3 years from April 2015. PLE is a fast, simple, easily automated technique, which permits to integrate a clean-up step during the extraction process reducing analysis time and stages. The proposed PLE-based procedure was optimized on real non-spiked baby wipe samples by means of experimental design to study the influence on extraction of parameters such as extraction solvent, temperature, extraction time, and sorbent type. Under the selected conditions, the method was validated showing satisfactory linearity, and intra-day, and inter-day precision. Recoveries were between 80–115% for most of the compounds with relative standard deviations (RSD) lower than 15%. Finally, twenty real samples were analyzed. Thirty-six of the target analytes were detected, highlighting the presence of phenoxyethanol in all analyzed samples at high concentration levels (up to 0.8%, 800μgg−1). Methyl paraben (MeP), and ethyl paraben (EtP) were found in 40-50% of the samples, and the recently banned isobutyl paraben (iBuP) and isopropyl paraben (iPrP), were detected in one and seven samples, respectively, at concentrations between 0.093 and 247μgg−1. In the case of phthalates, the forbidden phthalates dibutyl phtalate (DBP) and di(2-ethylhexyl)phthalate (DEHP) were also found in thirteen samples at low levels. All the samples contained fragrance allergens in many cases at high levels (up to 2400μgg−1) and three musks were detected in the samples. Excluding the banned compounds, all samples complied with the concentration limits established by the European Regulation although 25% of them did not fulfill the labeling requirements for fragrance allergens.

Characterization of plastic packaging additives: Food contact, stability and toxicity

Plastic additives are analyzed by spectrometric (FTIR, ICP-AES) and chromatographic (GC/MS, HPLC) methods in order to define their stability, purity and toxicity. All findings relate to the compounds identified in our packaging and their effect on human health. We wanted to show that some additives contain heavy metals (lead, cobalt, nickel, copper, etc.), highly toxic phtalates (Dibutyl phtalate or DBP) and contaminants (Non-intentionally added substances: NIAS, degradation products). Some additives used are even carcinogenic or tumorigenic.

The Effect of Carbon Fillers on Elastomer Composite Properties

The aim of this work was to obtain elastomer composite filled with carbon fillers with different structure. Three types of carbon black were used as reinforcing fillers: FEF N550, Colour Black FW200, Printex XE2B. In order to improve dispersion of fillers, different dispersing agents were used: anionic, cationic, nonionic and ionic liquids. As an elastomer matrix the acrylonitrile-butadiene rubber (NBR) was used. The fillers were characterized by dibutylphtalate (DBP) absorption analysis, aggregates size, rheological properties of filler suspensions and Zeta potential analysis. The compounding was carried out in a laboratory rolling mill. Samples were prepared through the vulcanization process at 160°C. The vulcanization kinetics of rubber compounds, crosslink density, mechanical properties, hysteresis losses, conductive and thermal properties of vulcanizates were also measured. In order to characterize filler dispersion in elastomer matrix the SEM images were obtained.

Highly Selective and Sensitive Coated-Wire Yttrium (III) Cation Selective Electrode Based on Kryptofix-22DD

An yttrium (III) cation selective electrode based on kryptofix-22DD (1,10-didecyl-1,10-diaza-18-crown-6) incorporated into a polyvinylchloride (PVC) membrane has been developed. The optimized membrane incorporating dibutylphtalate (DBP) as plasticizer, kryptofix-22DD and palmitic acid as a new component in a highly selective and sensitive coated wire electrode (CWE) for yttrium (III) cation was directly coated on the surface of a platinum wire electrode. The selective electrode showed more effective performance than other yttrium (III) cation PVC based sensors. The electrode exhibits a Nernstian slope (18.89 ± 0.43 mv.decade−1) in a wide linear concentration range of 1.0 × 10−8–1.0 × 10−1 M. The detection limit of electrode is 2.15 × 10−9 M. The effects of the pH and possible interfering ions were investigated and the optimized conditions for electrode were evaluated. The electrode was applied as an indicator electrode for potentiometric titration of yttrium (III) cation in solutions. Determination of fluoride ion in tap water, mouthwash and toothpaste gave results that compare favorably with those obtained by the fluoride ion selective electrode.

Effect of structure on the rate and mechanism of thermolysis of some 4-substituted 3-methylfuroxans

The gas-phase thermolysis of I proceeds as a unimolecular process and is independent of the initial vapor pressure of the substance (over 190 mm Hg) and of the ratio of the reaction vessel surface to its volume (S/V = 0.55–4.62 сm). In the melt and in solution in an inert solvent dibutylphtalate (DBP) the furazans decompose according to the first-order reaction law to the conversion level of 30–45 %. The substance content in the solution (1–10 %) does not affect the reaction rate.

Microbial deterioration of Mowilith DMC 2, Mowilith DM5 and Conrayt poly(vinyl acetate) emulsions used as binding media of paintings by pyrolysis-silylation-gas chromatography–mass spectrometry

Evaluation of the deterioration produced by microbiological attack on Mowilith DM5, Mowilith DMC2 and Conrayt poly(vinyl acetate) (PVA) emulsions has been carried out using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The proposed method includes the on-line derivatization of PVA emulsions using hexamethyldisilazane during pyrolysis. Specimens consisting of thin films formed on glass slides from dried PVA emulsions have been used. Py-GC–MS analyses performed on the specimens where the fungi Aspergillus niger, Penicillium chrysogenum, Trichoderma pseudokoningii, Cladosporium cladosporioides, Chaetomium globosum, Rhizopus oryzae, Aureobasidium pullulans, and the bacteria Streptomyces cellulofans, Bacillus amyloliquefaciens, Arthrobacter oxydans and Burkholderia cepacia were inoculated and allowed to grow, enable an evaluation of the effect of these microorganisms on the composition of the PVA emulsion. Decrease in the relative content of external plasticiser of phthalate type used in these PVA emulsions has been the main effect observed. Moreover, a different behavior was observed depending on the plasticiser present in every commercial PVA emulsion studied. Diisobutyl phthalate, used in Conrayt emulsion slightly varied its content in specimens inoculated with bacteria whereas dibutyl phtalate used in Mowilith DMC2 emulsion noticeably decreased its content in the specimens inoculated with fungi, thus suggesting that the effects of the metabolic processes associated to the latter microorganisms on the studied PVA emulsions are more significant than those from bacteria.

Nanoparticle encapsulation of emulsion droplets

The overall aim of this study is to coat emulsion droplets with nanoparticles using a simple heterocoagulation process in aqueous dispersion and determine: the adsorption behavior and interfacial layer microstructure, droplet physical stability against flocculation and coalescence, and the release profile of a model lipophilic molecule (dibutylphtalate (DBP)) from within the droplets. Polydimethylsiloxane (PDMS) droplets were used as a model emulsion due to their colloidal stability in the absence of added stabilisers. Aerosil™ type silica nanoparticles with different hydrophobicity levels were used as the model nanoparticles. The adsorption behavior of silica nanoparticles at the droplet–water interface was studied using adsorption isotherms and SEM imaging. Adsorption of hydrophilic nanoparticles is weakly influenced by pH, but significantly influenced by salt addition, whereas for hydrophobically modified nanoparticles a balance of hydrophobic and electrostatic forces controls adsorption over a wide range of pH and salt concentrations. The coalescence kinetics (determined under coagulation conditions at high salt concentration) and the physical structure of coalesced droplets were determined from optical microscopy. Adsorbed layers of hydrophilic nanoparticles introduced a barrier to coalescence of ∼1 kT and form kinetically unstable droplet networks at high salt concentrations. The highly structured and rigid adsorbed layers significantly reduce coalescence kinetics. Significant sustained release of DBP can be achieved using rigid layers of hydrophobic silica nanoparticles at the interface. Activation energies for release are in the range 580–630 kJ mol −1, 10 times higher than for barriers introduced by Pluronic ® stabilisers.

Evaluation of GPE performances in lithium metal battery technology by means of simple polarization tests

Gel polymer electrolyte (GPE) membranes based on two polymers, a copolymer of poly(vinylidene fluoride–hexafluoropropylene) (PVdF–HFP), and the poly(ethylene oxide) (PEO), together with a plasticizer, the dibutylphtalate (DBP), were elaborated in two ways. Firstly, the polymers and the plasticizer were mixed together to obtain a single membrane. Secondly, a bi-layer separator membrane was made by adjunction, through lamination, of a DBP plasticized PVdF–HFP film and a homemade DBP–PEO thin film. We report here a protocol based on a simple galvanostatic polarization of Li/GPE/Li symmetric cells as a way to rapidly screen new viable membranes. Such a procedure enables to quickly discriminate separators by leading experiments that do no not exceed 1 week compared to hundreds of days needed with classical batteries. The validity of such an approach was confirmed by investigating the performances of the membranes in Li/GPE/Li 4Ti 5O 12 flat battery configuration. Besides, through this study we also highlighted the role of the macroscopic PEO–PVdF interface toward dendrite of bi-layered separator, while a single blended membrane does not seem to be suitable for a practical use. Post-mortem pictures and SEM investigation have confirmed this result.

Applicability of liquid membranes in chromium(VI) transport with amines as ion carriers

Chromium(VI) transport across supported liquid membranes (SLMs) and polymer inclusion membranes (PIMs) with tertiary amines and quaternary ammonium salt (Aliquat 336) from chloride acidic aqueous solution to 0.1 M NaOH has been studied. The initial flux of Cr(VI) decreases linearly with logarithm of n-octanol/water partition coefficient increase for R 3N amines (R = n-C 6H 13– n-C 12H 25). The chromate ions are transported across polymer inclusion membranes with lower rate using polyvinyl chloride (PVC) instead of cellulose triacetate (CTA) support. The decreasing of Cr(VI) initial fluxes in following order of plasticizers: o-nitrophenyl pentyl ether > bis(2-ethylhexyl) adipate > dibutyl phtalate was observed. The comparative Cr(VI) transport studies of bulk, supported and polymer inclusion membranes were done. The highest permeability coefficient values for Cr(VI) was found for SLM, while the lowers values were observed for BLM. The repeated transport experiments of SLM and PIM were shown and the stability of PIM was described using the Danesi's thermodynamic model. The long-term integrity of PIM was found. Non-contact atomic force microscope was applied to obtain images of pores in polymer inclusion membranes.

Effects of bisphenol-A (BPA), dibutylphtalate (DBP), benzophenone-2 (BP2), procymidone (Proc), and linurone (Lin) on fat tissue, a variety of hormones and metabolic parameters: A 3 months comparison with effects of estradiol (E2) in ovariectomized (ovx) rats

The endocrine active substances BPA, DBP and BP2 have estrogenic effects in the uterus. Proc and Lin were shown to be antiandrogenic. Whether other estrogen-regulated parameters like lipids, fat metabolism and hormones are also affected by these substances is unknown. We compared the effects of a 3 months lasting administration of these substances with those of E2 on an estrogen-regulated fat depot and on serum TSH, T3, T4, LH, and lipid concentrations. BP2 shared many of the effects of E2 by suppressing LH, cholesterol, LDL, HDL and the size of a small estrogen-regulated fat depot in the lower hindleg. BP2 suppressed T4 but not T3 and TSH. The effects of DBP and BPA were mostly negligible whereas Lin and Proc also reduced the fat depot and serum leptin but increased triglycerides and serum lipids. Serum T3 and T4 concentrations were reduced by Lin and Proc. These data indicate that BP2 has similar, though slightly weaker effects as E2 whereas the effects of Proc and Lin differ from those of E2 on serum lipids and hormones. BP2 can be regarded as an estrogenic endocrine active substance whereas the effects of Lin and Proc appear not to involve estrogen receptors.

Room temperature lithium metal batteries based on a new Gel Polymer Electrolyte membrane

A new effective Gel Polymer Electrolyte membrane based on two polymers, the polyethylene oxide (PEO), a poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) copolymer and a plasticizer, the dibutylphtalate (DBP), was realized. This separator membrane was made by adjunction, through lamination, of an industrially made DBP/PVdF-HFP film and a homemade DBP/PEO thin film. Once the plasticizer was removed and the separator gelled by the electrolyte, the PEO enables the formation of a good interface with the lithium while the PVdF-HFP film brings the mechanical strength to the membrane. The electrochemical behavior of lithium batteries based on this bi-layer separator was investigated versus temperature, cycling potential and cycling rate. Owing to the promising results obtained with laboratory cells, a 1 Ah prototype was successfully assembled, and its cycling and rate performances were reported.

Pure estrogenic effect of benzophenone-2 (BP2) but not of bisphenol A (BPA) and dibutylphtalate (DBP) in uterus, vagina and bone.

Contradictory results whether the endocrine disrupters (ED) benzophenone-2 (BP2), bisphenol A (BPA) and dibutylphtalate (DBP) exert estrogenic effects have been published. Selective estrogen receptor modulators (SERMs) exert estrogenic effects in some but not in all organs and ED may be SERMs. Therefore, we studied their binding properties to recombinant ERalpha and ERbeta protein and their effects in the uterus, vagina and bone of ovariectomized rats. BP2 bound to both receptor subtypes, while BPA had a relatively high ERbeta selectivity. DBP did not bind to ERalpha but with a low affinity to ERbeta. In the uterus, only E2 and BP2 increased uterine weight and the complement C3 but decreased ERbeta gene expression. Discrete effects of BPA and DBP in the uterus were found upon histological examination. In the vagina, BP2 but not BPA and DBP had clear estrogenic effects. E2 and BP2 had antiosteoporotic effects in the metaphysis of the tibia. The serum surrogate parameters of bone metabolism, i.e. osteocalcin and the cross (rat) laps were significantly reduced by E2, an effect shared with BP2 but not by the two other EDs. BP2 acts as ERalpha and ERbeta agonist mimicking effects of E2, while the effects of BPA and DBP are not pure estrogenic.

Effect of oral intake of dibutyl phthalate on reproductive parameters of Long Evans rats and pre-pubertal development of their offspring.

To investigate the influence of dibutyl phtalate (DBP) given in a soy-free rat chow on pre-pubertal development, 46 Long Evans female rats 2-month-old were divided into three experimental groups and fed three different chows: (1) control; (2) DP 0.61 g/kg chow (12 mg/kgrat/day); (3) DP 2.5 g/kg chow (50 mg/kg rat/day) for 2 months. While under this treatment, they were mated and their offspring studied. Litter size and female:male ratio were recorded. At 14 days of age 6, male pups of each group were sacrificed and testis and thymus were excised and weighed. Pups were weaned at 22 days of age and continued into three experimental groups according to diet. From day 22 onwards, vaginal opening, occurrence of first estrous, and pre-putial separation were recorded. The percent of pregnancies showed a marked decrease in group 3, while no difference was observed between groups 1 and 2. Sex prevalence and litter size were not affected by the different diets. Pup survival showed a decrease when mothers were fed diet 2, but it was similar in diets 1 and 3. Pup weights on day 2 showed an evident (P < 0.05) reduction in groups 2 and 3, the decrease being more marked (P < 0.001) in group 3. On day 6, pups of group 2 showed lower weights (P < 0.01) as compared with the other groups. Weight gain was significantly higher in pups of group 3. Eye opening was not affected by the different diets. Fourteen-day-old male pups' relative weight of thymus and testis showed a decrease in animals whose mothers had been fed diets 2 and 3. Vaginal opening and occurrence of first estrous showed an evident delay (P < 0.05; P < 0.01) in females fed diets 2 and 3. Significant differences (P < 0.001) in pre-putial separation were observed between treated and untreated groups. Offspring pre-pubertal development seems to be affected by oral intake of DBP by their mothers during pregnancy, the effects being more evident in the reproductive development of male pups.

Universal Scaling of Alpha Relaxation in Complex Liquids

Abstract A plot is given, showing the result of a scaling analysis of dielectric loss curves containing, apart from low molecular glass former data (glycerol, dibutyl phtalate), also loss curves of the following liquid crystalline materials, mostly in the iso­ tropic phase: 4-(2-methylbutyl)-4'cyanobiphenyl (5*CB, supercooled isotropic phase), 4-cyano-4-n-alkyl biphenyls (nematogens 5CB and 8CB, isotropic phase), 4-(4-cyano-4-butylcyclohexyl)-4'-octylbiphenyl (laterally substituted nema-togen, isotropic phase), and 4-n-alkyl-4'-isothiocyanatobiphe-nyl (5 and 10 BT, isotropic and SmE phases). The plot applies the scaling formula originally proposed for glassforming, super­ cooled liquids [Dendzik et al.7]. The result supports the recent suggestion that dielectric relaxation in the isotropic phase of nematogens may show some features typical for "glassy" mate­ rials.

Low-energy vibrational density of states of plasticized poly(methyl methacrylate)

The low-energy vibrational density of states (VDOS)of hydrogenated or deuterated poly(methyl methacrylate)(PMMA)plasticized by dibutyl phtalate (DBP) is determined by inelastic neutron scattering.From experiment, it is equal to the sum of the ones of the PMMA and DBP components.However, a partition of the total low-energy VDOS among PMMA and DBP was observed.Contrary to Raman scattering, neutron scattering does not show enhancement of the boson peak due to plasticization.

Influence of fibre coating in headspace solid-phase microextraction–gas chromatographic analysis of aromatic and medicinal plants

Solid-phase microextraction (SPME) is a solvent-free technique, which is well established in headspace analysis since it is sensitive, because of the concentration factor achieved by the fibres, and selective, because of different coating materials which can be used. The performance of eight commercially available SPME fibres was compared to evaluate the recoveries of some characteristic components with different polarities and structures present in the headspace of four aromatic and medicinal plants: rosemary ( Rosmarinus officinalis L.), sage ( Salvia officinalis L.), thyme ( Thymus vulgaris L.) and valerian ( Valeriana officinalis L.). The relative concentration capacity of each fibre on the same components of each plant was also determined by comparing their abundance with that obtained by classical static-headspace GC. The partition coefficient, K 1, between the headspace gaseous phase and SPME polymeric coating, and the relative concentration factors, of some of the characteristic components of the plant investigated dissolved in dibutyl phtalate, were also determined, under rigorously standardised analysis conditions. The results showed that the most effective fibres were those consisting of two components, i.e., a liquid phase (polydimethylsiloxane) and a porous solid (carboxen or divinylbenzene, or both).

Conductive blends of polyaniline with plasticized poly(methyl methacrylate)

Polyaniline (PANI) protonated with camphorsulfonic acid (CSA) and three different poly(alkylene phosphates) (PAPs) (where alkylene = pentylene, hexylene, or nonylene) was used in the fabrication of conductive polyaniline–poly(methyl methacrylate) (PMMA) blends. The lowest percolation threshold (fp = 0.041 wt %) was obtained for the PANI(CSA)0.5–PMMA blend plasticized with 35 wt % of dibutyl phtalate (DBPh). This blend is also very resistant against the deprotonation of its conductive phase in basic solutions of pH = 9. In the case of blends prepared with the use of PAPs as PANI dopants, the percolation threshold strongly depends on the length of the hydrophobic spacer (alkylene group) in the dopant. The percolation threshold decreases in the order PPP > PHP > PNP, whereas the resistance against deprotonation in basic solutions decreases in the following inverse order: PNP > PHP > PPP. This last observation can be rationalized by increasing contribution of hydrophobic segments in the polymeric dopant, when going from PPP to PNP, which renders polyaniline more resistance toward the penetration by aqueous basic solutions. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 471–479, 1999

Determination of homogeneous nucleation rates from laminar-flow diffusion chamber data

MADMAcS 1 is a 2D algorithm for the simulation of coupled fluid flow, heat and mass transport, and aerosol dynamics based on the modal aerosol dynamics modelling technique ( Whitby, 1989, 1996; Wilck and Stratmann, 1997; Whitby and McMurry, 1997). It is applied to measurements of nucleation of dibutyl phtalate in a laminar flow diffusion chamber presented by Hämeri et al. (1996). A “linear range” is specified inside of which the relation between measured particle number concentrations and nucleation rates is easy and allows the determination of experimental nucleation rates. Based on this approach, a general inversion method for laminar flow diffusion chamber measurements is introduced that is insensitive against many simulation parameters. Moreover, the method can be carried out with simpler models than MADMAcS once the linear range is determined. In a preliminary sensitivity analysis, the thermodynamical properties of the involved substances, particularly the vapor pressure, are shown to be of crucial importance for the reliability of nucleation measurements.

NMR Evidence for Polymer/Solvent Complexes in Thermoreversible Gels

On the basis of measurements of selective and non-selective 1 H spin-lattice relaxation times of the solvent, the existence of polymer/solvent complexes (probably of the inclusion type) was evidenced for thermoreversible gels of syndiotactic PMMA in bromobenzene and for PVC gels in dibutyl phtalate or diethyl oxalate