Determination of lead, cadmium and arsenic from PVC food packaging materials by inductively coupled plasma mass spectrometry

Sujin Seo,Seongsoo Park,Kyungchul Cho,Sujin Bang,Juyeon Lee,Misook Kim,Minyoung Kim,Chul Joo Lim,Meehye Kim 한국분석과학회 2016 학술대회논문집 Vol.2016 No.11

Mononickel(II), dimercury(II), and 1-D polymeric silver(I) complexes with a ditopic 18-membered N₂O₂S₂-macrocycle

Seo, Sujin,Lee, Eunji,Ju, Huiyeong,Kim, Seulgi,Lee, Shim Sung ELSEVIER 2017 Inorganic Chemistry Communications Vol.83 No.-

<P><B>Abstract</B></P> <P>A ditopic 18-membered N<SUB>2</SUB>O<SUB>2</SUB>S<SUB>2</SUB>-macrocycle (<B>L</B>) incorporating hard (NO<SUB>2</SUB>) and soft (NS<SUB>2</SUB>) binding sites in each side was employed and its three complexes (<B>1</B>–<B>3</B>) exhibiting different stoichiometries, geometries, and topologies have been prepared and structurally characterized. First, nickel(II) nitrate hexahydrate reacts with <B>L</B> to give a mononuclear complex [Ni(<B>L</B>)](NO<SUB>3</SUB>)<SUB>2</SUB>·2H<SUB>2</SUB>O (<B>1</B>) in which the metal center locates inside the macrocyclic cavity adopting a hexa-coordinated octahedral geometry shielded by the strongly bound macrocycle from the anion and solvent. While, silver(I) tetrafluoroborate afforded a one-dimensional coordination polymer {[Ag(<B>L</B>)]BF<SUB>4</SUB>}<SUB> <I>n</I> </SUB> (<B>2</B>) with an <B>L</B>-Ag-<B>L</B>-Ag pattern. In <B>2</B>, the silver(I) center is penta-coordinate with NO donors from one <B>L</B> and NS<SUB>2</SUB> donors from an adjacent <B>L</B> to form a sandwich-type adopting a distorted trigonal bipyramidal geometry. Mercury(II) chloride yielded a dinuclear complex [Hg<SUB>2</SUB>(<B>L</B>)Cl<SUB>4</SUB>] (<B>3</B>) in which two mercury(II) ions locate opposite side of <B>L</B> in a chair form. Each mercury(II) center in <B>3</B> is penta-coordinate, being bound to one pyridine N atom, two O(S) donors in the compositional disorder, and two chloride ions adopting a distorted square-pyramidal geometry. The comparative NMR studies show the preferential binding affinity of silver(I) over potassium(I) toward <B>L</B>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three supramolecular complexes of a ditopic macrocycle including a 1-D silver(I) coordination polymer have been prepared and structurally characterized. </LI> <LI> Silver(I) tetrafluoroborate afforded a one-dimensional coordination polymer with an <B>L</B>-Ag-<B>L</B>-Ag pattern. </LI> <LI> The NMR studies of the ditopic macrocycle show the preferential binding affinity of silver(I) over potassium(I). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A ditopic 18-membered N<SUB>2</SUB>O<SUB>2</SUB>S<SUB>2</SUB>-macrocycle incorporating hard and soft binding sites was employed and its three complexes including a 1-D polymeric silver(I) complex have been prepared and structurally characterized.</P> <P>[DISPLAY OMISSION]</P>

Group 12 Metal Complexes of an 18-Membered N₂O₂S₂ Macrocycle Incorporating Two Pyridines: First Examples of an Infinite Mercury(I) Complex and a Dumbbell-Shaped Heteronuclear Complex with a Macrocyclic Ligand

Seo, Sujin,Ju, Huiyeong,Kim, Seulgi,Park, In-Hyeok,Lee, Eunji,Lee, Shim Sung American Chemical Society 2016 Inorganic Chemistry Vol.55 No.21

<P>Homo- and heteronuclear group 12 metal (Zn2+, Cd2+, and Hg2+) complexes 1-6 containing a newly designed 18-membered N2O2S2 macrocycle incorporating two pyridine subunits (L) were prepared and structurally characterized. The individual complexes isolated exhibit unusual stoichiometries, geometries, oxidation states, and structural topologies and include an infinite mercurous complex and a heteronuclear dumbbell-shaped complex. Both the Zn(II) complex [Zn(L)][ZnBr4] (1) and the Cd(II) complex [Cd(L)Br-2] (2) are mononuclear, with the metal ion located inside the macrocyclic cavity. The six-coordinated Zn(II) center in 1 adopts an octahedral geometry and is shielded from the anion and solvent by the strongly bound macrocycle. The Cd(II) center in 2 is seven-coordinate, being bound equatorially to two N donors, two 0 donors, and a S donor from the macrocycle and axially to two bromide ions on opposite sides of the macrocyclic plane, adopting a pentagonal-bipyramidal geometry. In the Hg(II) complexations, the configuration adopted by the macrocycle L shows a dependence of the nuclearity on the anion used. When mercury(II) bromide was used, the Binuclear complex [Hg-2(II)(L)Br-4] (3) was obtained, while the reaction with mercury(II) nitrate afforded the unexpected Hg(I) complex {[Hg-2(I)(L)](NO3)(2)} (4) with a one-dimensional polymeric structure. In heterometallic complexation experiments, one-pot reaction of L with a mixture of ZnBr2 and CdBr2 center dot 4H(2)O resulted in the stepwise isolation of two pure solubility-dependent Cd(II) complexes (2 and 5), including the half-dumbbell-type complex [Cd(L)(mu-Br)(CdBr3)] (5), while a mixture of CdBr2 center dot 4H(2)O and HgBr2 yielded the heterometallic bis(macrocycle) product [(CdL)(2)(mu-Hg2Br6)](Hg2Br6) (6). This is the first example of a heteronuclear dumbbell-shaped complex in which two terminal macroc-yclic Cd(II) complexes are linked by a hexabromodimercury(II) cluster via Cd-Br-Hg bonds. The heterometallic dumbbell 6 can be considered as a good example of competition and collaboration between Cd(II) and Hg(II) ions because its formation is associated with the higher coordination affinity of Cd(II) toward the macrocycle and the formation of the (Hg2Br6)(2-) cluster, which links the two endocyclic Cd(II) complexes directly. Both NMR titration and comparative NMR data indicate a relatively higher coordination affinity of Cd(II) toward the macrocycle than occurs for Hg(II), in parallel to the situation observed in the solid state.</P>

Chemical Properties of Artificially Buried Wood in an Intertidal Zone during the Deterioration Period

( Sujin Seo ),( Taekjoon Kim ),( Jae-won Lee ) 한국목재공학회 2020 목재공학 Vol.48 No.6

Wood deterioration experiments were carried out for 6 months in an intertidal zone of South Korea to monitor the changes in the chemical properties of two types of species, Korean red pine and sawtooth oak. The results of FT-IR spectra and XRD patterns have shown that the chemical properties of the wood did not change significantly during the 6-month burial period. However, the brightness of the surface decreased after burial; the value of the sawtooth oak sample was lower than that of the Korean red pine sample owing to an accumulation of inorganic compounds in cell lumen as observed by ICP analysis. Among the inorganic compounds, sodium and sulfur concentrations increased significantly over the burial period compared with the control. Further, the maximum moisture content decreased from 199% to 136% in the Korean red pine and 62% to 60% for the sawtooth oak. Nevertheless, the major chemical composition of both the wood species did not change significantly during the 6-month burial period, whereas, the crystallinity decreased with an increasing burial period owing to an accumulation of inorganic compounds in the lumen.

Analysis of Heavy Metals Migrated and 1,3-Butadiene Residue From Acrylonitrile-Butadiene-Styrene resin (ABS) Food Packaging Materials

SuJin Seo,HyeMi Kim,YongChjun Park,BoKyung Park,EunKyung Yoon 한국식품영양과학회 2020 한국식품영양과학회 학술대회발표집 Vol.2020 No.10

학령기 구어장애아동의 내면적 특성

서수진(Sujin Seo),신명선(Myungsun Shin) 한국언어치료학회 2014 言語治療硏究 Vol.23 No.2

Q 지수의 개선과 동작 주파수 조절을 위해 궤환 LC-공진기를 이용한 가변 능동 인덕터의 설계

서수진(Sujin Seo),유남식(Namsik Ryu),최흥재(Heungjae Choi),정용채(Yongchae Jeong) 한국전자파학회 2008 한국전자파학회논문지 Vol.19 No.3

본 논문에서는 종래의 접지된 능동 인덕터 구조와 궤환 가변 LC-공진기를 이용한 새로운 가변 능동 인덕터를 제안하였다. 접지된 능동 인덕터는 자이레이터-C 구조로 구현되며, 가변 LC-공진기는 낮은 Q 지수를 갖는 나선 인덕터와 바렉터로 이루어진다. 가변 LC-공진기는 트랜지스터의 기생 커패시턴스에 의한 Q 지수의 감소를 보상하며, LC-공진기의 공진 주파수 조절에 의해 높은 Q 지수를 갖는 주파수 대역을 가변할 수 있다. 매그나칩 0.18 ㎛ 공정을 이용하여 제작된 가변 능동 인덕터는 4.66~5.45 ㎓ 대역에서 바랙터 제어 전압 조정에 의해 높은 Q 지수를 갖는 주파수를 조정할 수 있으며, 동작 대역에서 50 이상의 Q 지수를 제공한다. 또한, 바렉터 제어전압 조정으로 5.1 ㎓에서 4.12~5.97 nH의 가변 인덕턴스 값을 얻을 수 있었다. In this paper, a new variable active inductor using a conventional grounded active inductor with feedback variable LC-resonator is proposed. The grounded active inductor is realized by the gyrator-C topology and the variable LCresonator is realized by the low-Q spiral inductor and varactor. This variable LC-resonator can compensate the degradation of Q-factor due to parasitic capacitance of a transistor, and the frequency range with high Q-factor is adjustable by resonance frequency adjustment of LC-resonator. The fabricated variable active inductor with Magnachip 0.18 ㎛ CMOS process shows that high-Q frequency range can be adjusted according to varactor control voltage from 4.66 ㎓ to 5.45 ㎓ and Q-factor is higher than 50 in the operating frequency ranges. The measured inductance at 4.9 ㎓ can be controlled from 4.12 nH to 5.97 nH by control voltage.

< 전시-P-64 > 조간대에 매몰된 목재의 열화시간에 따른 화학적 물리적 특성 분석

서수진 ( Sujin Seo ),김택준 ( Taekjoon Kim ),이재원 ( Jae-won Lee ) 한국목재공학회 2019 한국목재공학회 학술발표논문집 Vol.2019 No.1

갯벌이나 저습지는 산소가 차단되어 호기성 생물의 생장이 억제되는 환경으로 이곳에서 출토되는 목재 유물은 700년이 지나도 그 형태를 온전히 유지하고 있다. 일반적으로 최대함수율을 측정하여 목재 내부 분해도를 예측하지만 정확한 상태를 진단하기란 어렵다. 따라서 본 연구에서는 열화시간에 따른 목재 분해양상을 추적하고 최대함수율과의 상관관계를 살피고 열화 정도를 확인하고자 한다. 소나무와 참나무 각재를 경기 화성시 조간대 갯벌에 3개월, 6개월 동안 매몰하여 자연적으로 열화를 시킨 후 화학조성분석, XRD와 FT-IR분석을 실행하였다. 또한 퇴적물의 공극폐색을 확인하고자 현미경 관찰을 실시하였다. 소나무 3개월 열화시료에서 헤미셀룰로오스의 감소가 시작되었으며, 6개월 시료에서는 셀룰로오스와 헤미셀룰로오스가 감소한 결과를 나타냈다. 참나무는 3개월 열화시료에서 헤미셀룰로오스의 분해가 거의 일어나지 않았으며 6개월 시료에서 헤미셀룰로오스와 셀룰로오스의 감소를 확인하였다. XRD 분석을 통해 3개월 시료에서 소나무는 45.6%에서 50.9%로 결정화도가 증가하다가 6개월 시료에서는 41.9%로 결정영역이 감소한 것을 확인하였다. 참나무 시료에서도 48.0%에서 50.9%로 결정화도가 증가하였으며 6개월 시료에서 45.2%로 감소한 것을 확인하였다. FT-IR 분석 결과 두 수종 모두 3개월 시료에서부터 헤미셀룰로오스가 감소하고 6개월 시료에서 셀룰로오스가 감소하는 것을 확인하였다. 리그닌 피크에서 변화가 없는 것으로 보아 상대적으로 리그닌 분해는 일어나지 않았다. 최대함수율을 측정한 결과 소나무는 열화 시간에 따라 199%에서 155%, 136%로 감소하였고, 참나무는 62%에서 71%로 증가하다 60%로 감소하는 현상을 보였다. 이는 목재 공극에 토양 미립자가 흡착되어 최대함수율에 영향을 미친 것으로 판단된다. 현미경으로 시료 표면을 확대한 결과 토양 퇴적물을 확인하였다.

λ/4 개방형 CRLH 스터브와 LH 전송 선로를 이용한 주파수 체배기 설계

서수진(Sujin Seo),박상근(Sangkeun Park),최흥재(Heungjae Choi),정용채(Yongchae Jeong),임종식(Jongsik Lim) 한국전자파학회 2007 한국전자파학회논문지 Vol.18 No.11

본 논문에서는 composite right/left-handed 전송 선로를 이용한 주파수 체배기를 제안하였다. 제안된 주파수 체배기의 left-handed 전송 선로는 기본 주파수(f?) 성분을 억압하였고, composite right/left-handed λ/4 개방 스터브는 원하지 않는 고조파 신호 성분들을 제거하였다. Left-handed 전송 선로와 composite right/left-handed λ/4 개방 스터브를 조합하여 사용함으로, 오직 3차 및 4차 고조파와 같은 원하는 고조파 신호들만을 효과적으로 얻을 수 있었다. 본 논문의 타당성을 보이기 위해 기본 주파수를 1 ㎓로 하는 주파수 체배기를 설계하고, 측정하였다. 설계된 주파수 체배기의 입력 전력을 0 ㏈m으로 하였을 때, 측정된 3차 체배기와 4차 체배기의 출력 전력은 각각 -5.67 ㏈m과 -6.43 ㏈m이다. A novel frequency multiplier using composite right/left-handed transmission line is proposed. The left-handed transmission line in the proposed frequency multiplier suppresses the fundamental component(f?), while the composite right/left-handed λ/4 open stub diminishes unwanted harmonics. Due to the combination of the left-handed transmission line and composite right/left-handed λ/4 open stub, the only desirable multiplied frequency component such as 3 f? and 4 f? are obtained at the output port excellently. For the example of the proposed design, frequency multipliers are designed at 1 ㎓ of f? and measured. The measured output power of 3 f? and 4 f? is -5.67 ㏈m and -6.43 ㏈m, respectively, when the fundamental input power was 0 ㏈m.

Identification of Potocki–Lupski syndrome in patients with developmental delay and growth failure

Sujin Jun,Yena Lee,Arum Oh,Gu-Hwan Kim,Eulju Seo,Beom Hee Lee,Jin-Ho Choi,Han-Wook Yoo 대한의학유전학회 2019 대한의학유전학회지 Vol.16 No.2

Purpose: Potocki–Lupski syndrome (PTLS), is a recently identiἀed, rare genomic disorder. The patients are affected by in-fantile hypotonia, poor growth and developmental delay. Facial dysmorphism may not be obvious in some patients. PTLS is associated with microduplication at chromosome 17p11.2. In the current study, three Korean patients are reported with their clinical and genetic features. Materials and Methods: The clinical ἀndings of each patient were reviewed. Karyotyping and multiplex ligation-dependent probe ampliἀcation (MLPA) analyses were done for genetic diagnoses.Results: All the patients did not have the characteristic dysmorphic features, such as broad forehead, triangular face, asym-metric smile and palpebral ἀssures. On the other hand, all three patients were affected by variable degree of developmental delay, poor oral intake, failure to thrive, and language development disorders. Chromosome 17p11.2 duplication was identi-ἀed by conventional karyotyping analysis only in one patient, whereas the other conἀrmed by MLPA analyses.Conclusion: Delayed development was mostly commonly observed in our patients without distinct dysmorphic facial fea-tures. In this respect, genomic screening in patients with developmental delay would identify more cases with PTLS to under-stand their long-term clinical courses with the development of adequate psychological and rehabilitation education program.