Dipentyl Phthalate Research Articles

Phthalic esters in the indoor environment--test chamber studies on PVC-coated wallcoverings.

Phthalic acid esters are important additives in polyvinyl chloride (PVC) products. Since PVC plastisoles for the production of wallcoverings contain about 30% phthalic acid esters, it is a crucial question whether these products can contribute to the pollution of the indoor environment. In this study, the emission of several technically relevant phthalates from PVC-coated wallcoverings were measured in emission test chambers under standard room conditions. During a 14-day test period, both the chamber air concentrations and the condensation on a cooled plate (fogging) were determined. In the chamber air, maximum concentrations of 5.1 micrograms/m3 for di-n-butylphthalate (DBP), 2.08 micrograms/m3 for di-pentylphthalate (DPP) and 0.94 microgram/m3 for di-(2-ethylhexyl)phthalate (DEHP) were found. After 14 days of exposure, up to 60.4 micrograms DEHP and 17.7 micrograms DPP could be quantified on the cooled plates of the fogging apparatus. The amounts of DBP and DIBP were significantly lower. A simple exposure calculation indicated no specific risk of an increased phthalate exposure in rooms with PVC wallcoverings.

Determination of Acetochlor in Technical and Formulated Products by Capillary Gas Chromatography

A peer-verified gas chromatographic (GC) method is presented for the weight percent (wt %) determination of acetochlor herbicide in technical and formulated products. During method development, the method was found to be rugged by the Youden Ruggedness Test. Two laboratories with experience in the wt % determination of acetochlor in various matrixes participated in this study. Each laboratory received 10 blind duplicate test samples of the following 5 matrixes: one acetochlor technical and 4, different, emulsifiable concentrate (EC) formulations--Harness EC (MON 5841), Harness Export/Fist (MON 8435), Surpass EC (HF), and Surpass EC (LF). Each participant was asked to make duplicate weighings of each of the test samples and to inject each test sample solution twice. All test samples were analyzed on the same day, and 8 data points (replicates) per matrix were obtained. The test samples were dissolved in acetone that contained dipentyl phthalate as an internal standard. They were analyzed by GC on a 15 m capillary column by using split injection and a flame ionization detector. Acetochlor (wt %) was determined by comparing the ratios of peak area of acetochlor/peak area of dipentyl phthalate internal standard obtained for the test sample and calibration solutions. Repeatability of the method, expressed as the within-laboratory (between replicates) relative standard deviation (RSDr), was found to be 0.09-0.77% for the 5 matrixes. Reproducibility of the method, expressed as the within-test sample relative standard deviation (RSDR), was found to be 0.18-0.78% for the

Exposure to Phthalate Esters

Exposure to Phthalate Esters

Human Exposure Estimates for Phthalates

Human Exposure Estimates for Phthalates

Nuclearmagnetic relaxation study of carbon-13 in di-pentyl phthalate

Spin-lattice relaxation times T1 and nuclear Overhauser enhancement factors of chemically non-equivalent carbons in di-pentyl phthalate (DPP), a simple glass-forming liquid, are measured as functions of temperature. The analysis shows that the correlation function describing the overall molecular dynamics in DPP can be well described in terms of an asymmetric distribution of correlation times predicted by the Davidson-Cole model. The distribution parameters of the successive chain carbons are derived and analysed in terms of internal motions occurring in DPP.

97/03326 Treatment of flue gases from a fossil fuel-fired power plant using a compressed mixture

A rapid highly sensitive method based on accelerated solvent extraction (ASE) coupled with solid phase extraction (SPE) and gas chromatography mass spectrometry (ASE–SPE–GC–MS) has been developed for the analysis of seven commonly identified phthalates found in soil and biosolids including: dimethyl phthalate (DMP), diethyl phthalate (DEP), benzylbutyl phthalate (BBP), bis(2-diethylhexyl phthalate) (DEHP), di-n-octyl phthalate (DnOP), dipentyl phthalate (DPP) and di-n-butyl phthalate (DnBP). The developed method is capable of measuring phthalates in 15 min with sensitivity in the tenth of ng kg− 1 range. Parameters for ASE were investigated to render maximum efficiency of phthalate recovery using a tri-solvent extraction (ethyl acetate, hexane, dichloromethane) in a 2:3:2 ratio along with different temperatures and static periods. A detailed oven program was developed for the GC–MS analysis in which seven major phthalates were separated. The results obtained for recovery of phthalates ranged from 85 to 111% in tests on field soils and an alkaline treated biosolid. The method was successfully validated for the SPE extraction efficiency and the loss of content. The optimized method resulted in high sensitivity of measurement with the LOD ranging from 0.03 ng kg− 1 to 0.27 μg kg− 1 and the LOQ ranging from 0.1 ng kg− 1 to 0.87 μg kg− 1 with the RSD ranging from 4.4 to 9.8%. Concentrations of phthalates recovered in an agricultural field soil ranged from 0.03 ± 0.01 to 0.15 ± 0.04 ng g− 1 but were measured at 0.63 ± 0.1 to 4.3 ± 0.48 ng g− 1 in the same soil receiving an alkaline treated biosolid (ATB) amendment. The concentrations of phthalates found in the ATB used in the field soil ranged from 2.8 ± 0.81 to 8.3 ± 0.73 ng g− 1, and the concentrations of phthalates in the raw untreated sewage solids (w/w) ranged from 3.4 ± 0.79 to 14.9 ± 1.3 ng g− 1.

Hyamine 1622 - Selective PVC Membrane Electrodes Based onbis(Crown Ether)s

Abstract Hyamine 1622 - selective PVC membrane electrodes based on bis (crown ether)s containing the benzo - 18 - crown - 6 moiety were prepared, using o - nitrophenyloctylether (NPOE) or dipentylphthalate (DPP) as the plasticizer of the PVC membrane. Selectivity coefficients for various interfering ions (inorganic and organic cations), were determined by the mixed solution method. The selectivity of the respective electrodes was found to be affected by the kind of plasticizer employed, and NPOE seemed to be a more suitable plasticizer than DPP. The NPOE electrode system based on the bis (crown ether) that has 11 atoms between the two benzo-18-crown-6 moieties offers the advantage of greater selectivity. The electrodes show excellent electrode properties, and the electrode response was stable in a wide pH range.

Phthalate ester effects on rat sertoli cell function in vitro: Effects of phthalate side chain and age of animal

Mono(2-ethylhexyl) phthalate (MEHP), the active metabolite of the testicular toxicant di(2-ethylhexyl) phthalate, inhibits FSH-stimulated rat Sertoli cell cAMP accumulation, stimulates basal lactate production, and decreases intracellular ATP levels in vitro. Dibutyl phthalate and dipentyl phthalate but not diethyl-dimethyl or dipropyl are also age-dependent testicular toxicants in vivo. We therefore examined the effect of animal age and phthalate monoester on the Sertoli cell FSH-stimulated cAMP accumulation, lactate secretion, and ATP levels in order to determine if these effects are part of the mechanism of action of phthalate esters in vivo. MEHP, monobutyl and monopentyl phthalates but not the monoethyl, monomethyl, or monopropyl phthalates inhibited FSH-stimulated cAMP accumulation, a segregation which matches the in vivo toxicity potential of these agents. MEHP and monopentyl, but not monobutyl phthalates, also stimulated Sertoli cell lactate secretion. The effect of the active phthalates on FSH-stimulated cAMP accumulation and lactate secretion is not dependent on age of animal over a range of 13–80 days, suggesting that the age-related toxicity in vivo may be related to differences in metabolism and disposition rather than tissue sensitivity. Since the ED 50 of MEHP inhibition of cAMP accumulation and lactate secretion is similar, these two effects may be related to a common initial effect of the active phthalates. Inhibition of intracellular ATP levels is specific for MEHP and is lost with age (>28 days of age) and thus is not likely to be an essential part of the in vivo mechanism of action of phthalate diesters.

Impurity Problems in Chromatographic Method Studies for Fenthion Formulations

Abstract Several gas chromatographic (GC) methods for analyzing fenthion were studied, and flame ionization detection, a glass column packed with SE-52 on Chromosorb GHP, and on-column injection were selected as parameters. No suitable internal standard was found because of coeluting, bias-producing impurities in fenthion. Several liquid chromatographic (LC) methods were also studied, and UV detection, a Zorbax ODS column, and a methanol-water-H3P04 mobile phase were finally selected as parameters. Dipentyl phthalate was selected as internal standard. After testing, this LC method was submitted for collaborative study. During the collaborative study, the manufacturer found an impurity, 3-methyl-4-(methylthio)anisole, co-eluting with fenthion in the collaborative method. The manufacturer's method was then evaluated as an alternative for collaborative study, but a significant unidentified impurity from the formulation blank, used for formulating emulsifiable concentrates, was also found co-eluting with fenthion. The anisole impurity was verified by LC, and the presence of the S-isomer and bis-methylthio-fenthion impurities was found by gas chromatographic- mass spectrometric (GC-MS) analyses. An anisole material obtained from Mobay was also verified by GC-MS analysis. Several other impurities were identified from literature references and from private communication with the manufacturer.

Gas Chromatographic Determination of Metolachlor in Pesticide Formulations: Collaborative Study

Abstract A gas chromatographic (GC) procedure for the determination of metolachlor in emulsifiable concentrate formulations containing about 76% active ingredient was collaboratively studied using the matched pair scheme. Metolachlor was extracted from the formulation with acetone containing dipentyl phthalate as the internal standard, chromatographed on OV-101, and detected by flame ionization. Determinations on the 4 samples by 21 government, university, and industrial collaborators using peak area measurements showed within-laboratory repeatability of better than 0.5%. Reproducibility was better than 1% for the formulation. The method has been adopted official first action.

Effect of DI- n-pentyl phthalate treatment on testicular steroidogenic enzymes and cytochrome P-450 in the rat

Treatment of young male rats with dipentyl phthalate (DPP) produced significant decreases in testicular cytochrome P-450, cytochrome P-450 dependent microsomal steroidogenic enzymes (17α-hydroxylase, 17–20 lyase) and in the maximal binding of a natural substrate (progesterone) to testis microsomes. No effect was demonstrated by this compound on hepatic cytochrome P-450 content. Treatment of animals with a phthalate ester not causing testicular atrophy (diethyl phthalate; DEP) produced no significant changes in any of the parameters measured. This effect on the enzymes responsible for androgen production may be important as a mechanism of action involved in the development of phthalate-induced testicular damage.

Thallium(I)-selective PVC membrane electrodes based on BIS(crown ether)s

Thallium(I)-selective PVC membrane electrodes based on bis(crown ether)s containing benzo-15-crown-5 moiety were prepared, using o-nitrophenyloctylether(NPOE) or dipentylphthalate(DPP) as the plasticizer of the PVC membrane. Selectivity coefficients for various alkali and alkaline earth metal ions, kTIM, were sufficiently small, and were compared with those of the corresponding monocyclic analog and valinomycin. These electrodes show excellent electrode properties, and the electrode response was stable in a wide pH range.

Thallium(I)-selective PVC membrane electrodes based on bis(crown ether)s

Thallium(I)-selective PVC membrane electrodes based on bis(crown ether)s containing benzo-15-crown-5 moiety were prepared, using o-nitrophenyloctylether(NPOE) or dipentylphthalate(DPP) as the plasticizer of the PVC membrane. Selectivity coefficients for various alkali and alkaline earth metal ions, k TIM, were sufficiently small, and were compared with those of the corresponding monocyclic analog and valinomycin. These electrodes show excellent electrode properties, and the electrode response was stable in a wide pH range.

Effect of Plasticizer on the Selectivity of Potassium-selective PVC Membrane Electrodes Based on Bis(crown ether)s

Abstract Potassium-selective PVC membrane electrodes based on bis(crown ether)s containing benzo-15-crown-5 moiety were prepared, o-nitrophenyl octyl ether (NPOE) or dipentyl phthalate (DPP) being used as a plasticizer. Selectivity coefficients for various monovalent ions were measured. The preference of potassium over sodium in the bis(crown ether) (I; n=5)–NPOE electrode system is close to that in the valinomycin system.

ｃｉｓ‐ビス（クラウンエーテル）を用いるセシウムイオン選択性電極

Caesium-selective PVC membrane electrodes based on bis(crown ether)s [I], [II], [III] containing benzo-18-crown-6 moiety as a neutral carrier were prepared by using o-nitrophenyl octyl ether (NPOE) or dipentyl phthalate (DPP) as a plasticizer. Bis(crown ether)s were synthesized by potassium salt of maleic, fumaric and succinic acid with 4'-(chloromethyl)benzo-18-crown-6. The selectivity coefficients for various monovalent ions were measured in order to elucidate the effect of complexing property of these crown ether derivatives on the electrode response. [I] and [III] were found to exceed [II] in the selectivity coefficient, which reflects the formation of the stable 2: 1 complexes of crown ether ring and ion. The selectivity of the NPOE systems was generally superior to that of the DPP systems.

Interference of permeable anions in potassium-sensitive membrane electrodes based on valinomycin and dimethyldibenzo-30-crown-10

Responses of potassium-sensitive electrodes with valinomycin and dimethyldibenzo-30-crown-10 in the poly(vinyl chloride) membrane plasticized with dipentyl phthalate in solutions containing lipophilic anions, i.e., perchlorate and picrate have been measured. Using a general theoretical treatment, the role of possible ion pair formation in the membrane phase in the e.m.f./activity dependences is discussed. The electrode with a crown-compound is characterized by a broader region of cation response with an almost Nernstian slope. The possibility of extending the analytically useful range of these electrodes has been verified by using the membrane phase containing C 12 —C 14 phthalates.

Interference of permeable anions in potassium-sensitive membrane electrodes based on valinomycin and dimethyldibenzo-30-crown-10

Responses of potassium-sensitive electrodes with valinomycin and dimethyldibenzo-30-crown-10 in the poly(vinyl chloride) membrane plasticized with dipentyl phthalate in solutions containing lipophilic anions, i.e., perchlorate and picrate have been measured. Using a general theoretical treatment, the role of possible ion pair formation in the membrane phase in the e.m.f./activity dependences is discussed. The electrode with a crown-compound is characterized by a broader region of cation response with an almost Nernstian slope. The possibility of extending the analytically useful range of these electrodes has been verified by using the membrane phase containing C 12—C 14 phthalates.