燃燒法에 의한 黑色鑛物중 硫黃의 定量에 관한 硏究

김연두,배준현,전천석 충남대학교 자연과학연구소 1984 忠南科學硏究誌 Vol.11 No.2

The method burning completely the sulfur, by using the vanadium pentoxide in a current of the oxygen free of the sulfur dioxide, is employed to form sulfur trioxide. The sulfur trioxide in this gas mixture is absorbed by hydrogen peroxide solution and then converted to sulfuric acid. The sulfur is determined by titrating the sulfuric acid with standard sodium hydroxide solution after eliminating the carbon dioxide on warming.

분광광도법에 의한 염화철중 규소의 정량에서의 Amberlite LA-2의 이용

김연두,배준현,정현옥 충남대학교 자연과학연구소 1988 忠南科學硏究誌 Vol.15 No.1

For the photometric determination of silicon in the iron(Ⅲ) chloride, the iron(Ⅲ) was extracted to organic phase with Amberlite LA-2 in the cons. HCl solution. In the residual aqueous solution, the silicon was determined by molybdenum blue method. The method was found to be very useful to determine a low concentration of silicon in the concentrated iron sample.

분광 광도법에 의한 광물중 Nickel정량에서의 Amberlite LA-1의 이용

김연두,김종우,최기영 충남대학교 자연과학연구소 1983 忠南科學硏究誌 Vol.10 No.2

In the selective an quantitative determination of nickel by the dimethylglyoximate complexation from the ores, the undesirable impurities such as iron, cobalt and copper interfere the separation by forming the oximate complexes. To solve this problem, the extraction of these species with the liquid anion exchanger, amberlite LA-1, has been attempted. Nickel was completely separated with dimethylglyoxime in aqueous phase from the sample containing iron, aluminum, chromium, cobalt, copper, zinc and nickel after treating it with 50 ml of 5% amberite LA-1-xylene and the concentrated hydrochloric acid solution.

ICP-AES에 의한 수중의 금속 산화물 직접분석을 위한 연속흐름 Microwave 용해장치 개발 연구

김연두,이계호,김형승,김동수,박광규,Kim, Yeon Du,Lee, Gye Ho,Kim, Hyeong Seung,Kim, Dong Su,Park, Gwang Gyu 대한화학회 1994 대한화학회지 Vol.38 No.8

수중의 금속 산화물을 신속하고 간단하게 용해시킬 수 있는 연속흐름 마이크로파 용해장치를 개발하였다. 이로서 금속 산화물 입자를 용해시킴과 동시에 유도결합 플라즈마 분광기(ICP-AES)를 이용하여 ON-LINE으로 분석하는 완전 자동화 분석 장치의 개발이 가능토록 하였다. 연속흐름 마이크로파 용해장치는 개방형 튜브 장치와 억제형 튜브 장치로 구분하여 제작하고 최적화 시험을 수행하였다. 개방형 튜브 용해장치의 최적조건은 튜브길이가 30m, 마이크로파 출력 20%, 염산 농도 0.6N, 유속은 3.5ml/min였으며, 억제형 튜브 용해장치는 튜브 길이가 7.2m, 마이크로파 출력 30%, 염산 농도 0.6N, 유속은 3.1ml/min였다. 억제형 튜브 용해장치가 개방형 장치에 비하여 용해시간이 3배 정도 단축되었고 용해시킬 수 있는 시료의 농도 범위도 10배 정도 높았다. 제작된 용해장치의 정밀도는 베치식 용기 용해법과 거의 유사한 결과를 나타내어 Fe, Cu는 5% 정도의 상대 표준 편차값을 나타내었고, Zn,Co는 10%내외로 다소 높게 나타났다. The method described offers rapid and efficient sample preparation using on-line microwave digestion of metal oxides in water sample with direct elemental detection by ICP-AES. The open tubing digestion system(OTD) and the restraint tubing digestion system(RTD) for flow injection(FI) were designed and tested to find the optimum conditions. Comparison of OTD and RTD indicated that RTD was 3 times faster on the digestion time, and 10 times higher on sample mass. Finally, the results of RTD agree well with those by conventional microwave open vessel in all cases and show good precision; Fe and Cu show good with about 5% of RSD, while Zn and Co more or less than 10% RSD.

키레이트 滴定法에 의한 물중 칼슘, 마그네슘 定量에 있어서 Amberlite LA-2의 利用

김연두,배준현,김학수 충남대학교 1985 忠南科學硏究誌 Vol.12 No.2

This study is on the determination of calcium and magnesium in water at very low concentration. Iron(Ⅲ) was added to the sample, and calcium and magnesium were precipitated with iron by adding sodium carbonate and ammonia water. The precipitates were dissolved in conc-HCI and then Fe(Ⅲ) was removed by extraction with Amberlite LA-2. The residual aqueous solution containing calcium and magnesium were determined. Calcium and magnesium are determined by EDTA method respectively after separating them with sodium oxalate. This method, showing the small average relativity of error (less than 3.0%), is very useful to determine low concentration of calcium and magnesium in the water.

국내 우라늄 자원개발에 관한 연구

김연두,장원표,유석상 忠南大學校 1971 論文集 Vol.10 No.-

This experiment was conducted to find out uranium in graphites occurring in Ockchun boundary in Korea. About 200㎞, from Junjoo to Wonjoo, belongs to graphite of Ockchun boundary, we have investigated out resources of uranium, vanadium and molybdenum. The separation of uranium vanadium and molybdenum was carried out with a liquid anion exchanger such as Amberlite LA-1 and Amberlite LA-2 diluted with Xylene. These elements separated in the above method were quantitatively analyzed by colorimetric method after developing with H_2O_2, NaCNS and H_2O_2 in every solution. It was found that the highest contents of uranium was 0.2 percent in the samples of Taejon Geosan, and Keumsan.

중금속의 분리 및 검출을 위한 분석화학적 연구 (제 1 보). 새로운 분리방법의 개발

김연두,배준현,신영국,Kim, Youn-Doo,Bae, Jun-Heon,Shin, Young-Kook 대한화학회 1987 대한화학회지 Vol.31 No.3

니켈중 미량의 코발트를 분리하는데 액상음이온교환수지인 Amberlite LA-2를 이용하였다. 10M 염소이온 (4M HCl + 6M LiCl) 용액중에서 코발트는 ${CoCl_3}^-$를 형성하여 Amberlite LA-2 1ml에 2.175meq 추출되었다. 그러나 같은 조건의 염소이온용액에서 니켈은 착음이온을 형성하지 않으므로 전연 추출되지 않았다. 수지층에 추출된 코발트는 0.4M 질산용액에 의해 정량적으로 용리되었다. 코발트 50mg과 니켈 500mg을 녹인 합성시료용액중에 본 분리 방법을 적용시킨 결과 99.6%의 코발트를 분리회수 하였다. In 10M chloride (4M HCl + 6M LiCl) solution, cobalt, but not nickel, formed complex anion (${CoCl_3}^-$), and this anion was extracted by a liquid anion exchanger with Amberlite LA-2. The ion exchange capacity was 2.175meq of cobalt complex per unit ml of Amberlite LA-2. Upon eluting the resin with 0.4M nitric acid, the cobalt complex was stripped and transfered into eluate quantitatively. By using this separation method in the chloride solution dissolved with 50mg of cobalt (II) and 500mg of nikel(II), recovery of cobalt were 99.6 percent.

Monazite 중의 Uranium 정량

김연두,장원표,유석상 忠南大學校 1971 論文集 Vol.10 No.-

A new separation method of minor amounts of uranium was applied to the determination of uranium contents in monazites occurring in Kongju and Choongju in Korea. The separation method with a liquid anion exchanger such a Amberlite LA-2 diluted with xylene was faster and simpler than that with a solid exchanger resin. The samples of monazite were dissolved in hot and concentrated H_2SO_4. In 10N HCl, Uranium was quantitatively extracted by the organic phase, The stripping of uranium from the organic phase was carried out with 0.3N HNO_3. After reduction of iron, vanadium and molybdenum with H_2SO_3, the complete separation of uranium was possible by the extraction with the organic phase in 0.5N H_2SO_4. Uranium thus separated was determined colorimetrically after the development with H_2O_2. It was found that the cations such as C_e(Ⅲ), T_h(Ⅳ), V(Ⅴ), Z_n(Ⅱ), M_o(Ⅵ), C_u(Ⅱ), T_i(Ⅳ), M_n(Ⅱ) and F_e(Ⅲ), did not make any errors in the procedure (Table 3). Anions such as sulfate. phosphate, carbonate and chloride did not interfere on the separation of uranium (Table 4). The results of the analysis of monazite and graphite were showed at Table 5.

H_2O_2에 依한 Titanium의 分離에 關한 硏究

金演斗,朴茂淳 忠南大學校 1973 論文集 Vol.12 No.-

A hydrogen peroxide has been successfully used for the rapid separation of Titanium(Ⅳ) from the Titanium ore. Since in the presence of hydrogen peroxide with ammonia water Titanium(Ⅳ) isn't formed precipitate, but the Iron and the Aluminum are precipitated as the hydrated oxide. It is easy to separate the coexisting Titanium(Ⅳ) using hydrogen peroxide from Iron and Aluminum. After separation the remaining Titanium(Ⅳ) in the filterate is determined gravimetrically or colorimetrically acording to its contents. It has been found that the presence of such cations as Cr(Ⅵ), Ni(Ⅱ), Co(Ⅲ), Cu(Ⅱ), V(Ⅴ), and Mo (Ⅵ)give no interference in the above procedure.

鐵鋼中 몰리브덴의 定量

金演斗,朴茂淳 충남대학교 자연과학연구소 1978 學術硏究誌 Vol.5 No.1

The spectrophotometric determination of trace level of molybdenum in steels has been improved by modification of reduction system in the thiocyanste method. Ascorbic acid is used to reduce ferric ion to ferrous ion prior to addition of tin(Ⅱ) chloride solution. The ascorbic acid-tin(Ⅱ) chloride system exhibits better results than tin(Ⅱ) chloride alone when preconcentration of molybdenum-thiocyanste complex into methyl isobutyl ketone.