• 분석과학
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• 제37권5호
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• pp.271-279
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• 2024

Bisphenols and phthalates are endocrine-disrupting chemicals that are commonly used in packaging and as plasticizers. However, they pose health risks through ingestion, inhalation, and dermal contact. Accurate analysis of these pollutants is challenging owing to their low concentration and their presence in complex oil matrices. Therefore, they require efficient extraction and detection methods. In this study, an analytical method for the simultaneous quantification of bisphenols and phthalates in corn oil is developed. The dynamic multiple reaction monitoring mode of liquid chromatography-tandem mass spectrometry is used according to the different polarities of bisphenols and phthalates. The method is validated by assessing system suitability, linearity, accuracy, precision, homogeneity, and stability. The determination coefficients are higher than 0.99, which is acceptable. The percentage recovery and coefficient of variation of the accuracy and precision confirm that this analytical method is capable of simultaneously quantifying bisphenols and phthalates in corn oil. The bisphenols and phthalates in the formulations and pretreatment samples are stable for 7 d at room temperature and 24 h in an auto-sampler. Therefore, this validated analytical method is effective for the simultaneous quantification of bisphenols and phthalates in oils.

• 대한본초학회지
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• 제23권2호
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• pp.51-58
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• 2008

Objectives : Trimellitic anhydride (TMA), a sensitizer that induces occupational asthma and atopic dermatitis, is widely used industrially to make epoxy and alkyd resins, plasticizers, high temperature polymer, and surfactants. The aim of this study was to investigative the effects of aqueous extracts of Lonicera japonica Flower(LJFAE) on TMA-induced contact hypersensitivity (CHS) in Balb/c mice. Methods : The dried flowers of L. japonica were extracted with distilled water at $100^{\circ}C$ for 7 h. The extract was freeze-dried following filteration through 0.45 ${\mu}m$ filter. Mice were orally administrated with or without LJFE of a different doses(25-100 mg/kg) for 28 days. In the challenge period, mice were externally applied at difference doses of LJFAE one time per day 30 min before TMA treatment. We examined the effects of LJFAE on the the serum levels of IgE and prostagladin E2 (PGE2), the Thl/Th2 cytokine production of spleen cells, ear swelling responses, and the leukocyte infiltration induced by TMA. Results : The orally and externally administration of LJFAE dose-dependently reduced the serum levels of IgE and PGE2 production as well as ear swelling responses and leukocyte infiltration in TMA-induced Balb/c mice. Furthermore, the levels of Thl (TNF-${\alpha}$, IFN-${\gammer}$, IL-2)/Th2 (IL-4, IL-5, IL-13) cytokine production from spleen cells stimulated with anti-CD3 and CD28 mAbs was markedly suppressed by the orally and externally treatment with LJFAE in a concentration dependent manner. Conclusions : These results suggest that LJFAE suppresses the inflammatory mediators and regulates the Thl/Th2 cytokines. Therefore, these properties may contribute to the strong anti-CHS response effect of LJFAE.

• 환경생물
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• 제33권4호
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• pp.361-374
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• 2015

내분비계장애물질 (endocrine disruptors)은 포유류에서 축적되어 내분비계를 교란하며, 특히 수정능, 초기발생 등에 악영향을 미치고 암을 유발할 수 있는 것으로 잘 알려져 있다. 이러한 내분비계장애물질은 그 내분비계 교란 효과에 대한 지식이 부족하여 페인트, 코팅, 세제, 플라스틱 등에 활발히 사용되어 왔다. 특히 가정에서 내분비계장애물질은 음식 용기, 물병, 세탁용 세제 등에 사용되어 인체에 쉽게 노출되었다. 이후 내분비계장애물질의 위험성을 인식하면서 세계 각국에서는 내분비계장애물질의 생산 및 사용을 규제하고 대체재를 발굴하기 시작하였다. 그러나 현재까지 보고된 대체재의 안전성 또한 불확실하며, 이들의 인체에 대한 악영향을 완전히 파악하지 못한 채 사용하고 있다. 최근 이러한 대체재들 중 기존의 내분비계장애물질과 구조적으로 유사하고 내분비계 교란 효과를 갖는 물질이 있음이 밝혀졌으며, 이에 본 소고에서는 기존에 알려진 대표적인 내분비계장애물질인 bisphenol-A, phthalates, nonylphenols 및 이들의 대체재가 인체에 미치는 영향을 파악하고, 나아가 일부 대체재들에 대한 in-silico 분석을 수행함으로써 현존하는 대체재의 안전성에 의문을 제기하고 바람직한 소재 발굴을 위한 가이드를 제시하고자 하였다.

• Bulletin of the Korean Chemical Society
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• 제27권6호
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• pp.835-840
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• 2006

Dimethyl 1-(4-nitrobenzoyl)-8-oxo-2,8-dihydro-1H-pyrazolo[5,1-a]isoindole-2,3-dicarboxylate has been used as an ionophore and o-nitrophenyloctyl ether as a plasticizer in order to develop a poly(vinyl chloride)-based membrane electrode for calcium ion detection. The sensors exhibit significantly enhanced response towards calcium(II) ions over the concentration range $8.0{\times}10^{-7}\;1.0{\times}10^{-1}$ M at pH 3.0-11 with a lower detection limit of $5.0 {\times}10^{-7}$ M. The sensors display Nernstian slope of 29.5 ${\pm}$ 0.5 mV per decade for Ca(II) ions. Effects of plasticizers, lipophilic salts and various foreign common ions are tested. It has a fast response time within 10 s over the entire concentration range and can be used for at least 2 months without any divergence in potentials. The proposed electrode revealed good selectivity and response for $Ca^{2+}$ over a wide variety of other metal ions. The selectivity of the sensor is comparable with those reported for other such electrodes. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a Ca(II) solution, with EDTA.

• 분석과학
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• 제16권4호
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• pp.320-324
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• 2003

산성의약품의 선택성 액체막 전극을 전기활성물질로서 di-2-pyridyl ketone (DPK)-금속-산성의약품간의 삼성분착물로 제조하였다. 금속이온은 $Fe^{2+}$, $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$ 등을 사용하였고, 가소제는 니트로페닐에텔계를 사용하였다. 메페남산 선택성 막 전극은 pH 8.9의 붕산 완충용액중에서 그리고 이부프로펜 선택성 막 전극은 pH 7.0의 인산 완충용액 중에서 각각 $5{\times}10^{-5}{\sim}10^{-3}mol/L$ 농도에서 검정선이 얻어졌다. 메페남산 및 이부프로펜 표준품 일정량 첨가에 의한 회수율을 측정한 결과는 99.0%와 98.4%이었고 상대표준편차는 각각 2.4%와 2.6%이었다.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.11.1-11.6
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• 2016

Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor ("Survey on the work environment") and by the Ministry of Environment ("Survey on the circulation amount of chemicals"). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be $0.990mg/m^3$, as compared to the threshold exposure level of $5mg/m^3$. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below $5mg/m^3$ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.

• 공업화학
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• 제20권4호
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• pp.459-463
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• 2009

본 논문에서는 poly(vinyl acetate-co-ethylene) (VAE) 에멀젼에 가소제로 많이 사용되는 di-butyl phthalate (DBP)를 혼합하여 가소제 함량에 따른 물성 변화를 고찰하였다. 시차주사열량계(Differential Scanning Calorimeter) 측정으로부터 건조한 필름의 유리전이온도($T_g$)를 측정한 결과,가소제 함량의 증가에 따라, $T_g$는 감소하는 경향을 나타내었고 반면에 에멀젼의 점도는 가소제 함량의 증가와 더불어 증가하였다. 이러한 결과는 건조한 필름상태에서 가소제는 고분자사슬의 상호작용을 방해하여 $T_g$를 감소시키며 에멀젼 상에서는 가소제가 에멀젼 입자 내로 침투하여 swelling시킴으로써 입자크기가 증가하고 점도를 상승키는 것으로 나타났다. 기계적 물성은 가소제의 함량이 증가할수록 저하되었으나 내수성은 증가되는 결과를 얻었다.

• Macromolecular Research
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• 제11권6호
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• pp.431-436
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• 2003

A new photoconducting polymer, diphenyl hydrazone-substituted polysiloxane, was successfully synthesized by the hydrosilylation method and characterized by FT-IR, $^1$H-NMR, and $^{29}$ Si-NMR spectroscopy. The glass transition temperature (T$_{g}$) of the polysiloxane having pendant diphenyl hydrazone was ca. 62 $^{\circ}C$, which enabled a component of a low-T$_{g}$ photorefractive material to be prepared without the addition of any plasticizers. This polysiloxane, with 1 wt% of $C_{60}$ dopant, showed a high photoconductivity (2.8 ${\times}$ 10$^{-12}$ S/cm at 70 V/${\mu}{\textrm}{m}$) at 633 nm, which is necessary for fast build-up of the space-charge field. A photorefractive composite was prepared by adding a nonlinear optical chromophore, 2-{3-[2-(dibutylamino)-1-ethenyl]-5,5-dimethyl-2-cyclohexenylidene} malononitrile, into the photoconducting polysiloxane together with $C_{60}$ . This composite shows a large orientation birefringence ($\Delta$n = 2.6 ${\times}$ 10$^{-3}$ at 50 V/${\mu}{\textrm}{m}$) and a high diffraction efficiency of 81 % at an electric field of 40 V /${\mu}{\textrm}{m}$.textrm}{m}$.EX>.

• Elastomers and Composites
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• 제34권5호
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• pp.391-398
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• 1999

폴리염화비닐(PVC)에 프탈산계 가소제인 di-2-ethyl hexyl phthalate (DOP)와 아디프산계 가소제인 di-2-ethyl hexyl adiphate (DOA)를 혼련하였다. 혼련한 컴파운드의 비중, 인장강도, 신율, 경도, 내마모성, 내한굴곡성을 측정하였다. 먼저 PVC의 중합도에 따른 물성을 알아보면, 중합도 2500인 PVC를 사용한 컴파운드(이하 P2500계)가 중합도 1300인 PVC를 사용한 컴파운드(이하 P1300계)보다 인장강도, 경도에서 상대적으로 우수하게 나타났고, 신율, 내마모성, 내한굴곡성에서는 P1300계가 P2500계 보다 우수하게 나타났다. 그리고, 비중은 PVC의 중합도에 상관없이 비슷하게 나타났다. 또 가소제의 종류에 따른 PVC 컴파운드의 기계적 물성을 알아보면, 가소제로 DOP를 첨가한 PVC 컴파운드(이하 DOP계)가 DOA를 첨가한 PVC 컴파운드(이하 DOA계)보다 인장강도, 신율에서 우수하게 나타났고, 내마모성, 내한굴곡성에서는 DOA계가 상대적으로 DOP계보다 우수하게 나타났다. 그리고 경도는 DOP계가 높게, 비중은 DOA계가 더 낮게 나타났다.

• 한국추진공학회지
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• 제12권2호
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• pp.74-80
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• 2008

로켓엔진을 시동할 때 사용하는 터보펌프 시동기를 개발하기 위한 개발로직을 검토하고 기초실험을 통해 요구조건과 설계인자의 적용범위를 도출하였다. 시동기에 사용하는 고체추진제인 AN계 복합추진제는 고-에너지의 가소제와 냉각제를 사용하고 상온에서 AN의 상변화에 따른 급격한 부피변화를 완화하는 상안정화를 적용하였다. 시동기 설계를 위한 기초실험을 통해 추진제의 연소속도는 $0.2{\sim}0.3\;mm/s$ 이며 압력지수는 $0.3{\sim}0.6$ 범위인 경우 충분한 안정성을 확보함을 확인하였다. 신뢰성 있게 파이로 시동기를 작동하기 위해서는 점화에너지의 크기 및 점화에너지 전달방법이 중요하였으며, 선정한 AN계 복합추진제의 안정한 점화를 위한 화염온도의 하한한계는 1400 K로 평가되었다.