• Nuclear Engineering and Technology
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• v.4 no.1
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• pp.35-38
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• 1972

A study of the radiation-induced formation of carbonyl compounds in solid starch by means of precipitation with 2, 4-dinitrophenylhydrazine and subsequent analysis of the hydrazones by gas chromatograph has been performed. formation of carbonyl groups was found to increase linearly with increasing doses up to about 2$\times$10$^{21}$ eV/g. Generally, at least 5 different peaks can be detected including formaldehyde and acetaldehyde.

• Journal of Nutrition and Health
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• v.18 no.3
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• pp.189-193
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• 1985

Qualitative and quantitative analysis for carbonyl compounds contained in the five kinds of filtrated myulchichuts have been made using HPLC. Carbonyl compounds were separated by converting them into 2,4-dinitrophenylhydrazine derivatives which, in turn extracting with hexane. The extract was dehydrated, filtered and examined on HPLC with $C_{18}column$. The quantitative determination of carbonyl species was achieved using standard calibration technique. Highly reproduceable results were obtained by this methods and the amounts of 2,4-dinitrophenylhydrazine derivatives were highly correlative to peak heights. As the results, we find that the seven kinds of carbonyl compounds are contained in each of myulchichuts examined in this study. Five of which are identified as pyruvic acid, formaldehyde, acetaldehyde, acetone and butanone. But the amounts of carbonyl compounds vary widely with the kinds of the filtrated myulchichuts.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.25-30
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• 1973

2,6-Disubstituted-3-pyridazinones were synthesized by the reactions of $\gamma$,$\gamma$,$\gamma$-trichloroethylidene-m-nitroacetophenone with phenylhydrazine and substituted phenylhydrazines, and hydrazone was isolated as an intermediate from the reaction with 2, 4-dinitrophenylhydrazine. From the reaction with hydrazine hydrate 3-(m-nitrophenyl)-5-trichloromethyl-2-pyrazoline was obtained in good yield. The effect of substituents on phenyl group in the reaction of $\gamma$,$\gamma$,$\gamma$-trichloroethylidene-m-nitroacetophenone with substituted phenylhydrazines was also discussed.

• Journal of the Korean Chemical Society
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• v.23 no.5
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• pp.307-313
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• 1979

Seven new hydrazine derivatives were prepared from N-Aryllsufonylbenzimidoyl chloride. These were: ${\beta}-({\alpha}-Benzenesulfonamidobenzal)hydrazine\;(II),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)dimethylmethylenehydrazine\;(III),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)phenylhydrazine\;(VII),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-4-nitrophenylhydrazine\;(VIII),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-2,4-dinitrophenylhydrazine\;(IX),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)dimethylhydrazine\;(X),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-p-methylphenylhydrazine\;(XI)$. The structure of these derivatives were identified by elemental analysis, spectral data and other chemical methods. In general, it was found that the yields of these reactions were significantly improved in polar solvent and by the electron attracting substituents in phenylhydrazine.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.918-921
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• 2005

Quantitative analysis of flavonoids in commercial propolis extract products were compared by three colorimetric methods; aluminum chloride method, dinitrophenylhydrazine method and aluminum nitrate method, Aluminum nitrate method in Korea Health Supplement Food Code was proved to be specific only for flavones and flavonols same as aluminum chloride method, while dinitrophenylhydrazine method was specific for flavanones and dihydroflavonols. Therefore, the sum of flavonoid contents determined by 2,4-Dinitrophenylhydrazine method and aluminum nitrate method may represent the real content of total flavonoids. As for the 25 commercial propolis extract products examined, the contents of flavonoid varied from 2.15% to 9.53% except for one product.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.112-115
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• 1987

Gypsogenin was derivatized with 2, 4-dinitrophenylhyclrazine prior to analysis with HPLC. Reversed-phase column (Du pont ODS) was used and the mobile phase was acetonitrile and water (60:40). The effluent was detected at 550nm using an U.V. detector and the retention time was approximately 9.2min. The concentration was quantitated by measuring the area and the detection limit was 0.2$\mu\textrm{g}$.

• Journal of the Korean Chemical Society
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• v.16 no.3
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• pp.189-192
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• 1972

2, 6-Disubstituted-3-pyridazinones were synthesized from the reaction of trichloroethylideneacetophenone with substituted phenylhydrazines. Trichloroethylideneacetophenone 2, 4-dinitrophenylhydrazone was isolated from the reaction of trichloroethylideneacetophenone with 2, 4-dinitrophenylhydrazine and it gave 2-(2, 4-dinitrophenyl)-6-phenyl-3-pyridazinone through ring closure. This indicates that pyridazinones are produced through hydrazone formation and ring closure as suggested previously. The effect of substituents of phenylhydrazine on the reaction was also discussed.

• Polymer(Korea)
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• v.30 no.3
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• pp.210-216
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• 2006

To use the filter materials for selective removal of carbonyl compounds in cigarette mainstream smoke, hydrazine such as 2,4-dinitrophenylhydrazine (2,4-DNPH) and dansylhydrazine (DAH) impregnated adsorbents were prepared with perchloric acid or phosphoric acid as an accelerator in hydrazone formation reaction. Changes of molecular structure and morphology of adsorbents in various of impregnator were investigated by FTIR/ATR and SEM. Impregnation amount caused by reaction time, acid type and impregnation reagent, and the adsorption properties of carbonyl compounds in cigarette mainstream smoke were studied. Amounts of impregnation increased with increasing reaction time. The removal amount for vapor phase carbonyl compounds by 2,4-DNPH impregnated adsorbent was higher than that of dansylhydrazine impregnated adsorbent. The selectivity of 2,4-DNPH impregnated polyacrylic type adsorbent was superior to those of other adsorbents. This result indicates that the 2,4-DNPH impregnated polyacrylic adsorbent is applicable to cigarette filter material because of its fast reactivity and porosity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.65-73
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• 2016

Korea Food and Drug Administration (KFDA) has officially announced 2,4-dinitrophenylhydrazine (DNPH) derivatization - high performance liquid chromatography (HPLC) methods for analysis of formaldehyde. This study was conducted to develop a convenient derivatization method for cosmetics by improving complex pre-treatment procedures included in KFDA method. To simplify pre-treatment procedures of KFDA method, reaction conditions including pH, time and temperature were optimized. This pre-treatment method does not require complicate pre-treatment steps of KFDA method such as pH adjustment of test solution with acetate buffer (pH 5.0), solvent-solvent partitioning with dichloromethane and concentrating procedure with vacuum evaporator. Formaldehyde-dinitrophenylhydrazone (formaldehyde-DNP) product produced by derivatization reaction was separated and quantified with a reversed-phase HPLC, which was slightly modified with KFDA method. The linearity test showed good results with 0.9999 of correlation coefficient ($r^2$) in the range of 2 ~ 40 ppm of standard solutions. In this method, limit of detection (LOD) and limit of quantitation (LOQ) values for formaldehyde were 0.2 ppm and 0.5 ppm, respectively. In addition, recovery test demonstrated that the method was also accurate and reproducible. Therefore, the proposed method can be applicable to rapid analysis of formaldehyde in cosmetics.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.861-865
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• 2005

2,4-Dinitrophenylhydrazine (DHP), indophenol, and HPLC methods, which are generally used to analyze vitamin C, were evaluated by comparing changes in vitamin C contents in various samples kept at 10 and $20^{\circ}C$. Amount of total ascorbic acid (TAA) in yoghurt A kept at $10^{\circ}C$, as measured by DNP method, decreased from 26.7mg/100mL for early period to 22.8mg/100mL for final period of storage, whereas, on 3rd and 10th storage days, increased contrary to general results. Using indophenol, TAA measured at 28.6 and 9.5mg/100mL, and 30.5 and 14.6mg/100mL using HPLC far early and final periods, respectively. With indophenol and HPLC, TAA amount showed steady tendency to decrease. In conclusion, HPLC is the most suitable method to analyze vitamin C content, and indophenol method can be also used during early storage stage.