• Analytical Science and Technology
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• v.20 no.4
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• pp.308-314
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• 2007

The analytical method of HPLC with the radial-flow electrochemical cell (RFEC) has been developed to determine doxorubicin, epirubicin, nogalamycin, daunorubicin and idarubicin simultaneously by employing a reversed-phase chromatography. Anthracyclines were detected at -0.74 V vs. a Ag/AgCl (0.01 M NaCl) reference electrode, a potential of diffusion current plateau in the mobile phase. At a $V_f$ of 1.0 mL/min doxorubicin, epirubicin, daunorubicin and idarubicin appeared at a retention time ($t_r$) of 6.4 min, 7.4 min, 12.7 min and 18.4 min, respectively, while at a $V_f$ of 0.6 mL/min, doxorubicin, epirubicin, nogalamycin, daunorubicin and idarubicin appeared at a $t_r$ of 9.9 min, 11.5 min, 13.5 min, 19.6 min and 28.7 min, respectively. The linearity between each anthracycline injected ($2.40{\times}10^{-7}M{\sim}1.42{\times}10^{-5}M$) and peak area (charge) was excellent with the square of the correlation coefficient ($R^2$) higher than 0.999. The detection limits were $1.0{\times}10^{-8}M{\sim}1.5{\times}10^{-7}M$ for the five anthracyclines. Within-day precision for the five anthracyclines were in reasonable relative standard deviations less than 3 % ($1.00{\times}10^{-6}M{\sim}1.42{\times}10^{-5}M$) except the lower concentrations less than $0.7{\mu}M$. Solid phase extractions of $1.00{\times}10^{-5}M$ epirubicin, $0.48{\times}10^{-5}M$ nogalamycin and $1.52{\times}10^{-5}M$ daunorubicin from human serum with a $C_{18}$ cartridge resulted in 97 %, 100 % and 90 % of recoveries, respectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.118-125
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• 2001

Recently, biochemical analysis using hemoglobin adduct is frequently performed to evaluate the exposure to chemical carcinogens. However, data on the effect of co-exposure with other chemicals on hemoglobin adduct formation are seldom provided. The objective of this study is to evaluate the effects of pretreatment of ethanol(EtOH) and phenobarbital(PB), which are known to affect metabolism of xenobiotics, on the formation of hemoglobin adducts in the rats(Sprague-Dawley) administered benzidine(BZ). The experimental rats were divided into control, EtOH, and P8 groups. Rats were pretreated with EtOH or PB 24 hours before the oral administration of BZ. Blood sampling was taken before the administration of the chemicals and 0.5, 3, 6, 9, 12, 24, 48, 72, 96, and 144 hours after the administration of the BZ in 5 rats each. The blood was separated into hemoglobin and plasma immediately after taking the blood samples, and the adducts were undergone basic hydrolysis to convert them into aromatic amines. Hydrolyzed BZ, monoacetylbenzidine (MABZ), and 4-aminobiphenyl(4ABP) were separated by reversed-phase liquid chromatography without derivatization, and quantitative analyses of them were performed by a highperformance liquid chromatograph equipped with electrochemical detector. The quantitative amount of the metabolites was expressed by hemoglobin binding index(HBI), BZ-, MABZ-, and 4ABP-HBI of EtOH and PB groups were increased more than those of control group. These results are attributable to the fact that EtOH and PB induced N-hydroxylation related to the hemoglobin adduct formation. The ratio of N-acetylation (viz, MABZ-HBI/BZ-HBI) showed no significant difference between EtOH group and control group. It means that EtOH increased N-hydroxylation and N-acetylation in a similar degree. The N-acetylation ratio of PB group was relatively lower than control group because the PB increased N-hydroxylation induction. The N-acetylation ratios of all groups were higher than 1 during the entire experimental period. This result suggests that the effects of EtOH or PB need to be considered in the biochemical monitoring for the assessment of intermittent exposure of benzidine.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1194-1199
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• 2015

Vitamin $K_1$ (phylloquinone) content of commonly consumed foods in Korea were determined by solvent extraction followed by reversed-phase liquid chromatography using post-column derivatization and fluorescence detection. Samples were obtained in the years of 2013 and 2015. In this study, 46 vegetables, 14 fruits, and 6 legumes were analyzed. Relatively higher amounts of vitamin $K_1$ were found in sweet potato leaves, green kiwi, and mung beans among vegetables, fruits, and legumes, respectively. The content of vitamin $K_1$ in vegetables including spinach, broccoli, and potato ranged from non-detectable (ND) to $1,467.3{\mu}g/100g$. The content of vitamin $K_1$ in fruits ranged from ND to $42.7{\mu}g/100g$. The content of vitamin $K_1$ in legumes, including soybeans, mung beans and peas ranged from 1.7 to $63.4{\mu}g/100g$. In addition, the analytical method validation parameters including recovery, reproducibility, repeatability, peak purity, and linearity were calculated to ensure the method's validity. The results showed high linearity with a correlation coefficient of 0.9999. Overall recovery was close to 100% (n=5). This study revealed reliable vitamin K content in commonly consumed foods in Korea for a nutritional information and food composition database.

• Journal of Pharmacopuncture
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• v.17 no.4
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• pp.36-49
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• 2014

Objectives: Quercetin and curcuminoids are important bioactive compounds found in many herbs. Previously reported high performance liquid chromatography ultraviolet (HPLC-UV) methods for the detection of quercetin and curcuminoids have several disadvantages, including unsatisfactory separation times and lack of validation according the standard guidelines of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use. Methods: A rapid, specific, reversed phase, HPLC-UV method with an isocratic elution of acetonitrile and 2% v/v acetic acid (40% : 60% v/v) (pH 2.6) at a flow rate of 1.3 mL/minutes, a column temperature of $35^{\circ}C$, and ultraviolet (UV) detection at 370 nm was developed. The method was validated and applied to the quantification of different types of market available Chinese medicine extracts, pills and tablets. Results: The method allowed simultaneous determination of quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin in the concentration ranges of $0.00488-200{\mu}g/mL$, $0.625-320{\mu}g/mL$, $0.07813-320{\mu}g/mL$ and $0.03906-320{\mu}g/mL$, respectively. The limits of detection and quantification, respectively, were 0.00488 and $0.03906{\mu}g/mL$ for quercetin, 0.62500 and $2.50000{\mu}g/mL$ for bisdemethoxycurcumin, 0.07813 and $0.31250{\mu}g/mL$ for demethoxycurcumin, and 0.03906 and $0.07813{\mu}g/mL$ for curcumin. The percent relative intra day standard deviation (% RSD) values were $0.432-0.806{\mu}g/mL$, $0.576-0.723{\mu}g/mL$, $0.635-0.752{\mu}g/mL$ and $0.655-0.732{\mu}g/mL$ for quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin, respectively, and those for intra day precision were $0.323-0.968{\mu}g/mL$, $0.805-0.854{\mu}g/mL$, $0.078-0.844{\mu}g/mL$ and $0.275-0.829{\mu}g/mL$, respectively. The intra day accuracies were 99.589%-100.821%, 98.588%-101.084%, 9.289%-100.88%, and 98.292%-101.022% for quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin, respectively, and the inter day accuracy were 99.665%-103.06%, 97.669%-103.513%, 99.569%-103.617%, and 97.929%-103.606%, respectively. Conclusion: The method was found to be simple, accurate and precise and is recommended for routine quality control analysis of commercial Chinese medicine products containing the flour flavonoids as their principle components in the extracts.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.377-395
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• 1993

Habitat types, community structure and population characteristics of Koelreuteria paniculata were investigated in Mt. Wolak, Chungbuk and Naesokdong, Daegu, which are natural habitats of the species in inland region of Korea, and its origin was discussed. Habitats of Koelreuteria paniculata were classified to 3 types: sand bar formed by the sands flooded in the course of flow of the mountain stream (Type 1). crevice on the rock bed within the mountain stream (Type 2) and crevice of the rock around the edge of mountain stream (Type 3). Most Koelreuteria paniculata communities in Mt. Wolak site were composed of 3 layers of subtree layer, shrub layer and herb layer and that of Daegu site was 4 layers including tree layer. In the floristic composition of the Koelreuteria paniculata community, plants occurring frequently in the wet and open site, such as Zelkova serrata and Fraxinus rhynchoph-vlla showed high frequency. Frequency distribution of diameter at ground surface of Koelreutrria paniculata showed reversed J-shaped type. It was supposed that expansion of Koelreuteria paniculata community in Mt. Wolak site might be accomplished by the flow of the stream. Many saplings capable of becoming a successor of mature trees in Daegu site in near degenerating phase were established on the forest floor of the Koelreuteria paniculata community. From this result, it was supposed that these saplings originated from the seeds dispersed from a seed tree might form the Koelreuteria paniculata community of the next generation. On the other hand, the origin of Koelreutevia paniculata in inland sites was explained by two hypotheses: the one was that Koelreuteria paniculata might be transplanted by human and the other was that the present site might be native habitat of the community.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.381-385
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• 2004

This study was conducted to develop an HPLC method for determining pantothenic acid in fortified foods which has typically been determined by microbiological assay (MBA) according to AOAC and Korean Food Code approved methods. Pantothenic acid was determined by reversed-phase ion-pair HPLC using UV absorption (200 nm) after extraction with 20 mM potassium phosphate solution by sonication. The recovery of spiked samples and detection limit (LOD) by HPLC were 83.5∼109.6% and 0.5 ppm (mg/kg), respectively. The LOD of the microbiological assay (MBA) was much lower than that of HPLC. The concentrations of pantothenic acid analyzed in all tested samples (n=13) confirmed compliance with declared label claims. The range of recovery ratio by the HPLC method when compared to the microbiological assay was 91.9∼117.6%. There was not significant difference (p<0.01) between the HPLC and MBA methods and the equation of the regression curve was y=1.1428x-0.2269 (r=0.9842). This proposed HPLC method for determining pantothenic acid appears to be suitable for determining pantothenic acid concentrations above 0.25 mg/100 g in fortified foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1791-1795
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• 2014

The objective of this study was to compare two extraction methods for determination of vitamin K1 (phylloquinone) in vegetables. In addition, analytical method validation parameters such as accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and linearity were calculated to ensure the method's validity. Vitamin K1 was quantified by reversed-phase HPLC using post-column derivatization and fluorescence detection ($Ex{\lambda}=243nm$, $Ex{\lambda}=430nm$). Higher analytical values were observed using solvent extraction compared to those from the enzyme extraction method. The results from the method validation showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9994. The LOD and LOQ were 0.1335 and 0.2784 ng/injection volume ($50{\mu}L$), respectively. The inter-day precision and inter-day precision were 2.0% and 2.1%, respectively. Overall recovery was close to 100% (n=5). The phylloquinone contents ranged from 9.42 to $1,212.57{\mu}g/100g$. Our study provides reliable data on the phylloquinone contents in commonly consumed vegetables in Korea.

• Korean Journal of Environmental Agriculture
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• v.15 no.2
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• pp.167-178
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• 1996

In order to identify PCP glucose conjugates transformed from PCP in soybean and rice cell suspension cultures, the purified metabolites were acetylated, purified twice by HPLC using a normal and a reversed phase column, and then subjected to fast atom bombardment(FAB) mass spectrometric analysis. As were the conjugates, their acetylated derivatives of the glucose conjugates formed at the early stage(48 hr) of metabolism were separated by HPLC into three fractions. FABMS analysis of each fraction revealed that, at least in two fractions, the locations of the spectral peaks were practically coincident with those deducible from the structures of pentachlorophenyl and tetrachlorophenyl ${\beta}-D-glucopyranosides$. Based on information obtained from mass spectral and chromatographic analysis of not only the water-soluble metabolites but also aglycones and glycone, it is concluded that PCP is primarily metabolized to glucose conjugates, which account for more than 50% recovery of the PCP-conveyed radioactivity from the water soluble metabolites : The conjugates are mainly made up of pentachlorophenyl ${\beta}-D-glucopyranoside$, tetrachlorophenyl ${\beta}-D-glucopyranosides$( probably 2 or more isomers), and 2-hydroxy-3,4,5,6-tetrachlorophenyl ${\beta}-D-glucopyranoside$.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.580-583
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• 2007

Little is known about the genetic variability in lutein content for soybeans (Glycine max L.) cultivated in Korea. Therefore, the objective of this study was to screen high quality soybean cultivars for lutein content. The lutein contents of 23 recommended varieties, 56 sauce varieties, 44 sprout varieties, and 40 local varieties were determined by saponification followed by reversed phase high performance liquid chromatography (HPLC). We found that IT No. 153398 and 22789, originating from sauce and local varieties, respectively, contained significantly higher amounts of lutein as compared to the other 161 samples. Moreover, relevant quantitative differences were found among the samples, which had lutein contents ranging from 83 to $402{\mu}g/100g$ in the recommended varieties, from 39 to $778{\mu}g/100g$ in the sauce varieties, from 52 to $589{\mu}g/100g$ in the sprout varieties, and from 106 to $861{\mu}g/100 g$ in the local varieties, respectively. In summary, this study provides reliable lutein data for soybean cultivars that can be used for breeding studies and the development of functional foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1438-1446
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• 2011

Palmitoyl-oleoyl-oleoyl (POO) and palmitoyl-oleoyl-palmitoyl triacylglycerol rich fraction (PSL) was obtained from the acetone fractionation of palm stearin. The fatty acid composition (total and positional), tri-acylglycerol species, and solid fat index (SFI) were compared among the blends of natural vegetable fats (sal fat, illipe fat, kokum fat, shea stearin fat, and shea butter) and PSL with different ratios (50:50, 60:40, 65:35, 70:30). In total fatty acid composition of PSL, palmitic, oleic, and linoleic acids were the major fatty acids, whereas in natural vegetable fats stearic and palmitic acids were the major fatty acids. Moreover, oleic acid was a major fatty acid at sn-2 position in sal fat, illipe fat, and kokum fat. The TAG species was analyzed by reversed-phase HPLC, from which the PN value ranged from 46 to 54. When natural vegetable fats and PSL were blended with different ratios, decreasing the amount of PSL resulted in increasing SFI in most cases. Among blends, the SFI of sal fat and PSL were most similar to commercial cocoa butter equivalent (CBE).