• 한국식품과학회지
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• 제11권2호
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• pp.77-80
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• 1979

녹차중(綠茶中)의 L-ascorbic acid를 정량(定量)함에 있어서 흔히 사용되고 있는 DNP법(法)을 적용할 때 불순물(不純物)에 의한 방해(妨害)여부와 그의 제거방법(除去方法)에 대하여 검토(檢討)한 결과(結果)는 다음과 같다. 즉, DNP법(法)으로 AsA를 측정시 ethyl glyoxal, diacetyl, caffeine둥 불순물질 및 아미노산(酸)들이 방해하였으며, 이들 물질을 제거하는 수단으로 브롬산화(酸化)후 o-phenylenediamine을 반응시킨 다음 chloroform으로 추출제거(抽出除去)하고 Amberlite $IR-120(H^{+})$로 아미노산(酸)을 제거(除去)한 후에 DNP법(法)으로 비색정양(比色定量)하면 L-ascorbic acid 함량(含量)을 정확히 측정(測定)할 수 있었다. 또한 분석소요시간(分析所要時間)이 TLC법(法)에 비해서 현저히 단축되고 재현성(再現性)도 좋아서 녹차중(綠茶中)의 ascorbic acid 정량(定量)에는 본법(本法)이 적합함을 확인하였다.

• 펄프종이기술
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• 제43권3호
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• pp.52-58
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• 2011

Proton-NMR spectroscopic method was applied to kinetic study of concentrated sulfuric acid hydrolysis reaction, especially focused on 2nd step of acid hydrolysis with deferent reaction time and temperature as main variables. Commercial xylan extracted from beech wood was used as model compound. In concentrated acid hydrolysis, xylan was converted to xylose, which is unstable in 2nd hydrolysis condition, which decomposed to furfural or other reaction products. Without neutralization steps, proton-NMR spectroscopic analysis method was valid for analysis of not only monosaccharide (xylose) but also other reaction products (furfural and formic acid) in acid hydrolyzates from concentrated acid hydrolysis of xylan, which was the main advantages of this analytical method. Higher temperature and longer reaction time at 2nd step acid hydrolysis led to less xylose concentration in xylan acid hydrolyzate, especially at $120^{\circ}C$ and 120 min, which meant hydrolyzed xylose was converted to furfural or other reaction products. Loss of xylose was not match with furfural formation, which meant part of furfural was degraded to other undetected compounds. Formation of formic acid was unexpected from acidic dehydration of pentose, which might come from the glucuronic acid at the side chain of xylan.

• Journal of Ginseng Research
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• 제37권4호
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• pp.468-474
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• 2013

Ginseng seed oil was prepared using compressed, solvent, and supercritical fluid extraction methods of ginseng seeds, and the extraction yield, color, phenolic compounds, fatty acid contents, and phytosterol contents of the ginseng seed oil were analyzed. Yields were different depending on the roasting pretreatment and extraction method. Among the extraction methods, the yield of ginseng seed oil from supercritical fluid extraction under the conditions of 500 bar and $65^{\circ}C$ was the highest, at 17.48%. Color was not different based on the extraction method, but the b-value increased as the roasting time for compression extraction was increased. The b-values of ginseng seed oil following supercritical fluid extraction were 3.54 to 15.6 and those following compression extraction after roasting treatment at $200^{\circ}C$ for 30 min, were 20.49, which was the highest value. The result of the phenolic compounds composition showed the presence of gentisic acid, vanillic acid, ferulic acid, and cinnamic acid in the ginseng seed oil. No differences were detected in phenolic acid levels in ginseng seed oil extracted by compression extraction or solvent extraction, but vanillic acid tended to decrease as extraction pressure and temperature were increased for seed oil extracted by a supercritical fluid extraction method. The fatty acid composition of ginseng seed oil was not different based on the extraction method, and unsaturated fatty acids were >90% of all fatty acids, among which, oleic acid was the highest at 80%. Phytosterol analysis showed that ${\beta}$-sitosterol and stigmasterol were detected. The phytosterol content of ginseng seed oil following supercritical fluid extraction was 100.4 to 135.5 mg/100 g, and the phytosterol content following compression extraction and solvent extraction was 71.8 to 80.9 mg/100 g.

• 한국의류산업학회지
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• 제12권1호
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• pp.94-102
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• 2010

The dyeing of poly(trimethylene terephthalate)(PTT)/silk mixture fabrics can be accomplished by a two bath dyeing method with separate application of the disperse dyes on the PTT, reduction cleaning of the stained silk and then dyeing the silk with the acid dyes, or by one bath dyeing method with mixed dye ranges, possibly followed by a cleaning treatment. The two bath dyeing method has the advantage of better results with respect to dry cleaning fastness properties thanks to the possibility of an intermediate reduction clear. On the other hand, as compared with the two bath dyeing method, one bath dyeing method with a mixed dye range permits rapid and more reproducible dyeing, without the risk of great difference with respect to the shade of the strike on both substrates as well as savings of time, energy and water usage. This study was carried out to investigate dyeing characteristics of PTT/silk mixture fabrics with disperse dyes/acid dyes by one bath dyeing method in comparison with two bath dyeing method in the interests for rationalization of the dyeing process.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.199-202
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• 2004

In this study the field-scale tests were performed in which in-situ E/K remediation technologies were applied, and then the results were present. For traditional E/K remediation method the efficiency of remediation is not large, but the enhanced method with citric acid significantly increases the removal efficiency. Also EDTA, reported as a good enhancement agent for removal of heavy metals, is similar to that of citric acid. Therefore citric acid is preferred rather than EDTA in view of the cost on the contaminant removal per unit concentration.

• 대한가정학회지
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• 제9권2호
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• pp.34-39
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• 1971

By analyzing the relationships between the cookery methods and the loss of Ascorbic acid included in fresh vegetables, t he best cookery method to minimize the loss of it has been studied. For being scald and parch, those scald only in the water and those parch the salad oil had fained the least loss of it, while those parch had gotten generally the less loss than those scald. And when the cooked vegetables were left alone in the air. Ascorbic acid included in those were decayed exponentially, and its half time was about two hours.

• 한국의류산업학회지
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• 제7권3호
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• pp.339-345
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• 2005

It is difficult to dye nylon/viscose rayon mixture fabrics by one-bath one-step dyeing method, because acid dyes and reactive dyes require acidic dyebath for adsorption and alkaline dyebath for fixation respectively. In order to overcome the disadvantage of the conventional two bath two step dyeing method of nylon/viscose rayon mixture fabric, it was pretreated with cationizing agent containing chlorohydrine group in aqueous solution of sodium hydroxide. The pretreated nylon/viscose rayon mixture fabrics produced cationized fabrics that could be dyed with acid dyes and reactive dyes under neutral condition. This study was carried out to investigate dyeing possibilities, surface reflectance spectra and color characteristics of cationized nylon/viscose rayon mixture fabrics with acid dyes and reactive dyes in a non-electrolytic and neutral dyebath by one bath one step dyeing method.

• 한국염색가공학회지
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• 제9권5호
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• pp.75-81
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• 1997

o-Aminobenzene sulfone-N-ethylanilide, the diazo component of C.I. Acid Red 57, is currently being diazotised by the use of nitrosylsulphuric acid because of its high molecular weight and weak basicity. However, this method has many problems such as complicated manufacturing process and discharge of large volume of strong acidic effluent. In this study, the possibility of replacing nitrosylsulphuric acid method by direct method, which is simpler and produces less effluent, has been checked and the optimum process condition was studied. The effect of HCl concentration, the amount of sodium nitrite and particle size of diazo component on diazotisation yield was investigated. The optimum pH condition for coupling reaction was also evaluated.

• 한국식품조리과학회지
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• 제23권1호통권97호
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• pp.150-155
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• 2007

This work was conducted to obtain a rapid, accurate, and precise procedure for free amino acids analysis in Doenjang with HPLC-OPA (high performance liquid chromatography using-phthalaldehyde) and AAA (automatic amino acid analyzer) methods. Different sample extraction procedures among water, 0.1 M perchloric acid, and 0.1% meta-phosphoric acid were also compared. The optimal extraction solvent was 0.1% meta-phosphoric acid for both the HPLC-OPA and AAA methods. Good recoveries for glycine and methionine were observed using the 0.1% meta-phosphoric acid extraction with HPLC-OPA method. Method precisions (% relative standard deviation) for the free amino acids ranged for 1.62% to 8.27%, in which the HPLC-OPA method with water extraction showed the lowest value at 1.62%. Inhibition rates of the free amino acids in Doenjang were greatest with an addition of NaCI at a 1% concentration.

• 약학회지
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• 제29권5호
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• pp.227-233
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• 1985

A new method of determination of fatty acid using gas chromatography-flame photometric detector (GC-FPD) is described. Fatty acid was methylthiomethyl-esterified with methylthiomethy chloride in 1,8-diazabicyclo [5,4,0]-undec-7-ene catalyst and its concentration measured by GC-FPD with 3%OV-1 or 3% FS-1 column. The FPD responses of thirteen fatty acid methylthiomethyl esters were examined and were proportional to the concentration of the esters without regard to their chemical structures. Consequently it was possible to determine various fatty acid using one standard calibration curve by GC-FPD. We could rapidly and conveniently determine varous fatty acids using one standard calibration curve by GC-FPD. We could rapidly and conveniently determine 13 fatty acids in Ginseng Radix alba by this method.