수령별 백합나무의 열분해 산물 동정

엄인용(In-Yong Eom),김광호(Kwang-Ho Kim),이수민(Soo-Min Lee),이오규(Oh-Kyu Lee),여환명(Hwanmyoung Yeo),최인규(In Gyu Choi),최준원(Joon-Weon Choi) 한국산림바이오에너지학회 2009 산림바이오에너지 Vol.28 No.1

본 연구는 백합나무의 바이오에너지 원료 적합성을 조사하기 위해 생장기간 별로 목부와 수피로 분리하여 원소 조성과 화학적 조성분석을 실시하였고 열화학적 분해산물은 pyrolysis-GC/MS를 이용하여 분석하였다. 백합나무의 원소조성은 목부와 수피조직에서 거의 유사하게 나타났으며, 각각의 발열량에도 차이가 없는 것으로 분석되었다. 백합나무 목부조직의 홀로셀룰로오스 함량과 리그닌 함량은 생장기간(6년, 11년, 20년)에 관계없이 각각 80±2%와 21±1%로 큰 변화가 없었으며, 수피조직의 홀로셀룰로오스와 리그닌 함량은 목부조직보다 낮은 64% 와 16% 정도로 나타났다. 백합나무 목부조직의 주요 열분해 산물의 조성은 생장기간에 크게 영향을 받지 않는 것으로 분석되었다. 셀룰로오스/헤미셀룰로오스에서 유래한 퓨란계 화합물(4종)과 cyclopentene 화합물(3종)이 대표적이었고, 리그닌 분해산물로는 C6C₃형인 2,6-dimethoxy-4-(2-propenyl)-phenol(S형)과 2-methoxy-4-(2-propenyl)-phenol(G형)의 비율이 다른 페놀류보다 높게 나타났다. 수피조직의 리그닌 열분해 산물은 목부조직과 다르게 C6C₃형 비율은 훨씬 낮은 반면, C6C₁형인 vanillic acid의 비율이 목부조직에 비해 상당히 높게 나타났다. This study was performed to assess a compatibility for yellow poplar as a raw material of biofuel conversion process. Xylem tissue as well as bark tissue of yellow poplar grown at 6, 11 and 20 years, respectively, were subjected to elemental analysis and chemical composition analysis and thermal degradation products of each sample were analyzed by pyrolysis-GC/MS. Irrespective of growth year as well as xylem and bark elemental composition were almost similar. Holocellulose and lignin content of xylem tissues were not also influenced by growth year and determined to 80±2% and 21±1%, respectively. In comparison to xylem tissues holocellulose and lignin content in bark tissue, however, were relative lower to 64% and 16%. As thermal degradation products from cellulose/hemicellulose the relative proportions of furan derivatives(4 structures) and cyclopentene derivatives(3 structures) were significant. 2,6-dimethoxy-4-(2-propenyl)-phenol(S type) and 2-methoxy-4-(2-propenyl)-phenol(G type), which have C6C₃ forms, were representative in xylem tissue as lignin derived products. In case of bark tissue the portion of C6C₃ derivatives were distinctively reduced, while high yield of vanillic acid(C6C₁ structure) was released as lignin degradation products.

LED-photometer 제작을 위한 광센서로서의 발광다이오드의 이용

엄인용 ( In Yong Eom ) 대구가톨릭대학교 자연과학연구소 2010 자연과학연구논문집 Vol.8 No.1

Light emitting diodes (LEDs) are small and inexpensive. They produce very stable and narrow emission band when forward biased. These notable characteristics make LEDs replace conventional light sources in many applications. In addition, a LED can be used as a light transducer. Interestingly, the detector LED only can register the narrow band of wavelength which is the same as the LED is emitting. This feature can eliminate the use of an optical filter which is usually used to extract the certain wavelength if needed. The author fabricated the home-made spectrophotometer using two identical LEDs: one is for light source and another is for light sensing. The good linearity (r-squared value = 0.9997) of absorbance of a methyl orange in the concentration range of 0.49 - 51.48 μM and the calculated LOD of 0.37 μM proves that the home-made LED-photometer can be used widely for simple quantitavie analysis as well as for pedagogical purpose both in general and analytical chemistry lab courses.

CCoAOMT 유전자 발현 억제에 의한 현사시나무의 화학조성 변화

엄인용 ( In Yong Eom ),김광호 ( Kwang Ho Kim ),이수민 ( Soo Min Lee ),이용섭 ( Yong Sub Yi ),최준원 ( Joon Weon Choi ) 한국목재공학회 2010 목재공학 Vol.38 No.3

In this study, chemical compositions-holocellulose, lignin and monomeric sugars-were characterized with two poplar wood cell walls, one of which was grown at normal condition (CPW) and the other was genetically modified by antisence suppression of CCoAOMT gene expression (ACPW). Milled wood lignins were isolated from CPW and ACPW and subjected to methoxyl group, DFRC, Py-GC/MS, GPC, 13C-NMR analysis, respectively. There were few differences in holocellulose contents in both cell walls, which were determined to 81.6% in CPW and to 82.3% in ACPW. However, lignin contents in ACPW was clearly decreased by the suppression of CCoAOMT gene expression. In CPW 21.7% of lignin contents was determined, while lignin contents in ACPW was lowered to 18.3%. The relative poor solubility of ACPW in alkali solution could be attributed to the reduction of lignin content. The glucose contents of CPW and ACPW were measured to 511.0 mg/g and 584.8 mg/g and xylose contents 217.8 mg/g and 187.5 mg/g, respectively, indicating that suppression of CCoAOMT gene expression could be also influenced to the formation of monomeric sugar compositions. In depth investigation for milled wood lignin (MWL) isolated from both samples revealed that the methoxyl contents at ACPW was decreased by 7% in comparison to that of CPW, which were indirectly evidenced by 13C-NMR spectra and Py-GC/MS. According to the data from Py-GC/MS S/G ratios of lignin in CPW and ACPW were determined to 0.59 and 0.44, respectively. As conclusive remark, the biosynthesis of syringyl unit could be further influenced by antisense suppression of CCoAOMT during phenylpropanoid pathway in the plant cell wall rather than that of guaiacyl unit.

화장품 내 유해 중금속 정량

이후승 ( Lee Hooseoung ),최유진 ( Choi Yujin ),정양효 ( Jung Yanghyo ),윤수정 ( Yoon Soojung ),이선영 ( Lee Sunyoung ),문주영 ( Moon Jooyoung ),엄인용 ( Eom In-yong ) 대구가톨릭대학교 자연과학연구소 2018 자연과학연구논문집 Vol.16 No.1

An experiment was conducted on mask-pack, foundation, mascara and lipstick. And we measured the heavy metal concentration [ppm(μg/mg)] of As, Cd, and Pb. To see the difference of their concentrations, all tested products were classified based on price and functionality, color, and chroma specifically. The result of this study was as follows. First, both As and Pb were detected in all cosmetic products while Cd was detected in 46.7% out of tested products. Second, detected As average was as in the following. mask-pack was 0.555ppm, foundation was 0.223ppm, mascara was 0.250ppm and lipstick was 0.350ppm. So all samples were remarkably lower than standard-10ppm. Third, Cd wasn’t detected in mask-pack and lipstick. And detected Cd average was as in the following. Foundation was 0.030ppm and mascara was 0.167ppm. So they were lower than standard-5ppm. Forth, detected Pb average was as in the following. mask-pack was 26.985ppm, foundation was 10.403ppm, mascara was 8.223ppm and lipstick was 1.800ppm. In mask-pack, all samples exceeded the standard-20ppm. In foundation, only one sample of the brightest color(17) exceeded the standard. In conclusion, our predictions that the lower price product will be contained more heavy metal were inconsistent with the result. But we found correlation about functionality, color and chroma.

Needle Trap Device (NTD)를 위한 열탈착 장치의 제작과 특성 평가

엄인용 ( In Yong Eom ),정민지 ( Min Ji Jung ) 대구가톨릭대학교 자연과학연구소 2015 자연과학연구논문집 Vol.13 No.1

주사기형 소형 흡착 장치 (needle trap device, NTD)를 위한 열탈착 장치를 제작하고 특성을 평가하였다. 소형 카트리지형 히터와 온도 센서 및 온도조절장치를 사용하여 제작된 NTD용 열탈착 장치는 비교적 짧은 warm-up 시간 (10분 이하)를 필요로 하며, 온도 fluctuation 없이 매우 안정적으로 사용될 수 있음을 확인하였다. 이 장치를 이용하여 Dimethyl methylphosphonate(DMMP)의 carry-over 시험을 통해 적정 흡착 온도 (250 ℃)를 확인할 수 있었다.

Membrane Extraction-IMS System을 이용한 Dimethyl Sulfide (DMS)의 포집/분석법 개발에 관한 연구

엄인용 ( In Yong Eom ) 대구가톨릭대학교 자연과학연구소 2012 자연과학연구논문집 Vol.10 No.1

Membrane Extraction Sorbent Interface(MESI), Ion Mobility Spectrometer(IMS), Needle Trap Device(NTD), Volatile Organic Compounds (VOCs), Dimethyl Sulfide (DMS) Membrane extraction module (ME)과 ion mobility spectrometer (IMS)을 연결한 system을 이용하여 Dimethyl sulfide (DMS)의 포집 및 분석 가능성에 관한 연구를 수행하였다. ME module을 이용하여 공기 중으로부터 DMS를 분리 가능성을 IMS의 플라즈마그램 (plasmagram) 분석을 통하여 확인하였다. ME with a sorbent interface (MESI) system의 흡착 tube 개발을 위해, Needle Trap Device (NTD)를 먼저 제작하여 DMS에 대한 열탈착 온도 (thermal desorption temperature)와 시간에 따른 carry-over (%)를 수행하였다. 본보고서의 실험 결과는 DMS 포집/분석에 이용할 수 있는 현장 분석이 가능한 (field affordable analysis) MESI-IMS system 개발에 이용될 것이다.

여러 형태의 Polydimethyl Siloxane (PDMS) 흡착제로 제작된 Needle Trap Device (NTD)의 포집 효율 비교

엄인용 ( In Yong Eom ) 대구가톨릭대학교 자연과학연구소 2011 자연과학연구논문집 Vol.9 No.1

여러 형태의 Polydimethyl Siloxane (PDMS) 충진된 needle trap device (NTD)를 제작하고 각 NTD의 포집 효율을 decane과 undecane을 이용하여 비교하여 보았다. 비교를 위해 DVB로 포집된 NTD를 사용하였다. DVB NTD의 포집효율에 비해 여러 형태의 PDMS NTD의 효율을 상대적으로 매우 낮았다. PDMS film이나 used PDMS fiber의 경우 매우 간단한 방법으로 제작할 수 있는 반면, 충진 방법을 개선하여 breakthrough volume을 개선할 필요가 있음을 확인하였다. 상업용으로 시판되는 PDMS modified sorbent (10 % SP)의 경우, decane과 undecane의 포집효율이 가장 낮아서, PDMS의 sorbent 표면의 modification 효율을 높여야 함을 확인하였다.

Peroxidase/H2O2 조건에서 리그닌 전구물질에 따른 탈수소 중합반응 특성 연구

문선주 ( Sun Joo Moon ),김광호 ( Kwang Ho Kim ),엄인용 ( In Yong Eom ),이수민 ( Soo Min Lee ),김용환 ( Yong Hwan Kim ),최준원 ( Joon Weon Choi ) 한국목재공학회 2010 목재공학 Vol.38 No.3

In this study diverse dehydrogenative polymers (DHPs) were synthesized with three precursors of native lignin [p-coumaryl alcohol (PCA), coniferyl alcohol (CA), sinapyl alcohol (SA)] in the presence of horseradish peroxidase (HRP, EC. 1.11.1.7)/H2O2. To compare the structural features between DHPs and native lignin, the DHPs as well as pine/poplar milled wood lignins were simultaneously subjected to gel permeation chromatography (GPC) to determine average molecular weights and derivatization followed by reductive cleavage (DFRC) to investigate the frequency of β-O-4 linkage. The highest yield of DHP was measured to 71% when CA was solely injected (G-DHP) and the yield of H-DHP was 42%. However, single injection of SA could not form any polymer in this system. The average molecular weights of DHPs were ranged between 3,000∼4,700, which were only 1/2 fold compared with that of pine MWL (G-type lignin: Mw 7,340) and 1/3 scale compared with that of poplar MWL (GS-type lignin: Mw 13,250). DFRC analysis revealed that the formation of β-O-4 linkage during dehydrogenative polymerization was the highest in the GS-DHP with ca. 502 μmol/g, which was, however, remained to only 50% compared to that in poplar MWL (1107 μmol/g). The β-O-4 linkage was estimated to ca. 286 μmol/g In the G-DHP, which was twice as much as that of H-DHP(127 μmol/g). Similar to GS-DHP, only half amount of β-O-4 linkage, compared to pine MWL, was formed during in vitro polymerization of CA by horseradish peroxidase/H2O2.

Differential Argentometric Titration Equipped with a Reflectance Detector for the Determination of Halogen Anions

황훈,엄인용,Hwang, Hoon,Eom, In-Yong Korean Chemical Society 2010 대한화학회지 Vol.54 No.5

엑셀 해찾기 프로그램을 통한 구리-아연 혼합용액의 분석

김라윤,엄인용,Kim, Ra Yun,Eom, In-Yong 대한화학회 2021 대한화학회지 Vol.65 No.2