헬륨 마이크로파 플라즈마 토치의 개발과 특성에 관한 연구

曺競鉉,朴勇男 한국교원대학교 환경과학연구소 2002 환경연구논문집 Vol.- No.7

MPT는 최근에 개발된 마이크로파 플라즈마로서 수용매에 강하다. 여러 가지의 변형된 형태의 MPT를 개발하여 구조에 따른 플라즈마의 방전되는 형태를 조사한 결과 이중관 토치는 플라즈마 기체를 적게 소모하며 쉽게 플라즈마가 형성되었으나 토치의 끝이 높은 온도에 견디지 못하고 쉽게 상했다. ICP토치와 같은 형태의 삼중관 토치에 석영관을 중심관으로 사용할 때 가장 안정되고 대칭적인 플라즈마를 형성할 수 있었다. 바탕선을 조사해 본 결과 He MPT는 대기 중으로 돌출되어 대기와 많이 혼합되고 질소에 의해 quenching되는 것으로 보여진다. Membrane desolvator를 탈용매화 장치로 사용하여 헬륨 MPT의 감도를 조사해 본 결과 아르곤 MPT와 비교할 때 대부분의 원소에 대해 검출한계가 10배 이상 높았다. 그러나 여기 에너지가 높은 원소는 비교적 효율적으로 검출할 수 있었다. 헬륨 마이크로파 플라즈마는 적은 양의 플라즈마 기체만 필요하여(약 1.6L/min)경제적이며 매우 안정된 형태를 보여주었다. 플라즈마의 분광특성을 조사한 결과 들뜸온도 4950K, 전자밀도 3.28×10^14㎝^-3로 측정되었다. MPT, which has been developed recently, is very tolerant to aqueous samples. Several types of MPT have been investigated and is found that the double concentric tube could sustain a stable plasma at a low plasma gas flow rate. However, the tip of torch is easily ruined. Triple concentric torch has shown the best stability and the plasma shape, much like that of ICP, especially when the central channel is quartz. The plasma is exposed and mixed with air is suggested from the background spectrum, which leads to quenching of He MPT. Sensitivity of helium MPT equipped with a membrane desolvator has shown 10 times lower than that of Argon MPT for most of elements except for the ones with relatively high excitation energy. He MPT requires small plasma flow rate(about 1.6L/min), stable and simple to use. Excitational temperature and electron number density measured are 4950 K and 3.28×10^14㎝^-3, respectively.

헬륨 마이크로파 플라즈마 토치의 개발과 특성에 관한 연구

曺競鉉,朴勇男 한국교원대학교 환경과학연구소 2001 환경연구논문집 Vol.- No.6

MPT는 최근에 개발된 마이크로파 플라즈마로서 수용매에 강하다. 여러 가지의 변형된 형태의 MPT를 개발하여 구조에 따른 플라즈마의 방전되는 형태를 조사한 결과 이중관 토치는 플라즈마 기체를 적게 소모하여 쉽게 플라즈마가 형성되었으나 토치의 끝이 높은 온도에 견디지 못하고 쉽게 상했다. ICP토치와 같은 형태의 삼중관 토치에 석영관을 중심관으로 사용할 때 가장 안정되고 대칭적인 플라즈마를 형성할 수 있었다. 바탕선을 조사해 본 결과 He MPT는 대기 중으로 돌출되어 대기와 많이 혼합되고 질소에 의해 quenching되는 것으로 보여진다. Membrane desolvator를 탈용매화 장치로 사용하여 헬륨 MPT의 감도를 조사해 본 결과 아르곤 MPT와 비교할 때 대부분의 원소에 대헤 검출한계가 10배 이상 높았다. 그러나 여기 에너지가 높은 원소는 비교적 효율적으로 검출할 수 있었다. 헬륨 마이크로파 플라즈마는 적은 양의 플라즈마 기체만 필요하여(약 1.6L/min) 경제적이며 매우 안정된 형태를 보여주었다. 플라즈마의 분광특성을 조사한 결과 들뜸온도 4950 K, 전자 밀도 3.28×10^(14) cm^(-3)로 측정되었다. MPT, which bas been developed recently, is very tolerant to aqueous samples. Several types of MPT have been investigated and is found that the double concentric tube could sustain a stable plasma at a low plasma gas flow rate. However, the tip of torch is easily ruined. Triple concentric torch has shown the best stability and the plasma shape, much like that of ICP, especially when the central channel is quartz. The plasma is exposed and mixed with air as is suggested from the background spectrum, which leads to quenching of He MPT. Sensitivity of helium MPT equipped with a membrane desolvator has shown 10 times lower than that of Argon MPT for most of elements except for the ones with relatively high excitation energy. He MPT requires small plasma flow rate (about 1.6 L/min), stable and simple to use. Excitational temperature and electron number density measured are 4950 K and 3.28 × 10^(14) cm^(-3), respectively.

접촉각 측정으로 본 표면 장력 관련 교육 내용 및 고등학교 학생틀의 이해 분석

최종국,박용남,백성혜 韓國敎員大學校 敎育硏究院 2009 敎員敎育 Vol.25 No.4

이 연구에서는 극성 액체인 물, 에탄올 및 비극성 액체인 사염화탄소를 극성 표변인 유리와 비극성고체인 PVC와 테플론판 위에 떨어뜨린 후 접촉각을 측정하고, 액체 증기, 고체 증기, 및 고체-액체의 경계간의 자유에너지 (□_(LV), □_(SV), □_(SL))와 표면장력을 계산하였다. 접촉각의 크기는 액체의 종류 또는 표면장력 뿐 아니라, 고제 판의 특성에 따라서도 달라진다는 것을 확인하였다. 또한, 접촉각의 크기는 액체의 표면 장력의 크기와 반드시 일치하지는 않았다. 7차 교육과정의 ‘화학 I’ 교과서 8종과 여러 평가 문항들을 분석한 결과, 접촉각과 표면 장력의 크기를 단순히 분자 간 인력에 따라 비례하는 것으로 표현하는 경우가 있었고, 교육과정에서 요구하는 수준을 념거나 현실적으로 관찰되지 않는 상황을 제시하는 경우도 있었다. 고등학교 학생들은 접촉각 표면장력 그리고 분자간 인력에 관련된 이해가 부족한 것으로 나타났다. Interfacial free energies(□_(LV), □_(SV), and □_(SL)) were calculated from the measured contact angles between various solid surfaces and liquids. Polar liquid, water and ethanol, as well as non-polar liquid such as carbon tetrachloride were examined on the polar surface such as glass as well as non-polar surface PVC and Teflon. The contact angle showed dependence on characteristics of both liquids and solid surfaces. More importantly, the order of contact angle did not agree with that of surface tension From the analysis of 8 types of 'Chemistry l' textbooks and several assesment items, the errors are found that the contact angle and surface tension are proportional to intermolecular interaction. In some cases, the required knowledge is above current educational level or some unrealistic situation is used as an example. The high school students are appeared to be incomprehensible to complex relationships between contact angle, surface tension, and intermolecular interactions.

크로마토그래피-유도 결합 플라스마 원자방출 분광법을 이용한 희토류 원소들의 연속적 분석 및 직교형과 초음파분무기의 비교

연평흠,박용남 한국교원대학교 환경과학연구소 2004 환경연구논문집 Vol.- No.8

이온교환 크로마토그래피와 유도결합 플라스마를 연결하여 회토류 원소들을 연속적으로 분리 검출할 수 있었다. 특히 HPLC와 주사형 분광기를 사용하여 파장을 옮기면서 여러 회토류 원소를 동시에 측정하는 것이 가능하였음을 보여주었다. 현재의 분리에서는 8개의 원소에 대하여 주사형 분광기로도 분리 가능하나 용리액기울기를 더 잘 활용한다면 모든 원소들에 대하여서도 연속적분리가 가능할 것으로 예측한다. 기존의 직교형 분무기로도 HPLC-ICP의 희토류연구에 충분하지만 초음파 분무기가 더 유용하며 바탕의 증가등으로 감도와 분해능은 예상된 결과에는 미치지 못하였으나 감도는 수배 가량의 개선됨을 알 수 있었다.

Chiro-Inositol-Containing Inositol Phospholipid and Metabolism upon Salt Stress in Soybean Seedling

Hong, Yong-Geun;Kim, Seok-Yong;Nam, Im-Sook;Pak, Yun-bae,Kim, Seok-Yong,Nam, Im-Sook,Pak, Yun-bae Gyeongsang National University 1997 Plant molecular biology and biotechnology research Vol.1997 No.

Errors in Isotope Dilution Caused by Matrix-induced Mass Bias Effect in Quadrupole Inductively Coupled Plasma-Mass Spectrometry

Pak, Yong-Nam Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.12

Matrix-induced mass bias and its effect on the accuracy of isotope ratio measurements have been examined for a quadrupole-based inductively coupled plasma-mass spectrometer (Q ICP-MS). Matrix-induced mass bias effect was directly proportional to % mass difference, and its magnitude varied for element and nebulizer flow rate. For a given element and conditions in a day, the effect was consistent. The isotope ratio of Cd106/Cd114 under $200{\mu}g\;g^{-1}$ U matrix deviated from the natural value significantly by 3.5%. When Cd 111 and Cd114 were used for the quantification of Cd with isotope dilution (ID) method, the average of differences between the calculated and measured concentrations was -0.034% for samples without matrix ($0.076{\mu}g\;g^{-1}$ to $0.21{\mu}g\;g^{-1}$ for the period of 6 months). However, the error was as large as 1.5% for samples with $200{\mu}g\;g^{-1}$ U. The error in ID caused by matrix could be larger when larger mass difference isotopes are used.

Removal of OH Spectral Interferences from Aqueous Solvents in Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) with Ar Cryogenic Desolvation

Yong Nam Pak,Youngmin Cho 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.9

The spectral interferences of OH from aqueous solvents in ICP-AES have been studied and eliminated using a cryogenic argon trap. The prominent lines of Bi I 306.772 nm, Al I 309.271 nm, and V II 310.230 nm, which are very seriously overlapped with the OH band, were examined. With an extended torch and high tangential flow of 20 L/min, water vapor from air entrainment was prevented. The combination of a condenser and argon cryogenic trap was able to eliminated most of water vapor carried by the argon sample gas. Removal of OH spectral interference could extend the linearity of the calibration curve 5-10 times on the lower concentration for ICP-AES. Interference Equivalent Concentration (IEC) has been reduced to 5.6, 5.9, and 12.4 times for Bi, Al and V, respectively.

Preconcentration of Cd by Continuous Hydroxide Precipitation-Dissolution in Atomic Emission Spectrometry

Pak,Yong-Nam,Huh,Girl,Pyung,Heum Yeon 한국교원대학교 환경과학연구소 1998 환경연구논문집 Vol.- No.4

On-line preconcentration by direct precipitation with hydroxide has been developed and applied for the analysis of Cd in Inductively Coupled Plasma Atomic Emission Spectrometry. Cadmium is continuously precipitated with hydroxide and dissolved by nitric acid in on-line mode. Currently, the enrichment factor is more than 90 times for 20.0 mL of sample and could be further increased very easily. For a large sample throughput, 1.0 mL of sample loop is used and the enrichment factor is 4.5 with the sampling speed of 15/hr. The method has been applied to the analysis of NIST reference sample and has yielded good results with the certified value.

A New On-line Coprecipitation Preconcentration Technique for Trace Metal Analysis by ICP-AES

Pak,Yong-Nam,Park,Kyung Hee 한국교원대학교 환경과학연구소 1996 환경연구논문집 Vol.- No.3

In a stream of water sample, trace metal ions are quantitatively coprecipitated with Indium hydroxide and filtered. The filtered precipitate is continuously dissolved in 3 M nitric acid and introduced to ICP directly. The lead, cadmium, and copper are concentrated more than 10-fold and determined with ICP-AES at a sampling frequency of 10/hour. The detection limits are 2.89, 1.43, 0.52 ppb for lead, cadmium, and copper respectively. Recoveries of lead, cadmium, and copper are 98.7, 94.3, and 104.5% respectively. The RSD values for three elements are about 3-5% currently.

A Study of Laminar Flow Torch in Microwave Induced Plasma Atomic Emission Spectrometry

Pak,Yong-Nam,Yoo, Hee-See,Roh, Sae-Weon 한국교원대학교 환경과학연구소 1996 환경연구논문집 Vol.- No.3

A comparative study of different torches in the Microwave Induced Plasma is reported. Three types of torches that have been used in this area are characterized and compared with each other. Especially, recently developed laminar flow torches have been optimized in design and analytical performances. The ratio of inner to outer tubes is found to be the most important parameter. As inner tube size increases, recirculating region also increases and consequently, sensitivity becomes better. An optimized laminar flow torch has been coupled to a gas chromatography and examined for halogen compounds. Detection limits are 25 pg ?? for Cl and 12 pg ?? for Br. These values are improved over the conventional laminar flow torch.