• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.593-598
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• 2009

In this study, the qualitative and quantitative analytical method for petroleum marker(Unimark 1494DB) in common diesel involved kerosene and byproduct fuel was developed using SPE pretreatment and high performance liquid chromatography. In SPE pretreatment process, the highest concentrated marker was obtained 15 minutes after addition of petroleum sample. The petroleum marker was detected with $1626.92mV{\cdot}sec$ intensity at 9.8 minutes retention time in 1 mg/L content in petrodiesel after pretreatment. Also petroleum marker was selectively identified in an acidic petroleum product which was previously difficult to be analyzed by UV-Vis Spectroscopy.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1437-1441
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• 2000

Acycloretinoic acid was prepared from acycloretinal by oxidation with Tollens reagent. Acycloretinoic acid was separated with Silica-HPLC and analyzed by ODS-HPLC with a photodiode array detector and by GC-MS. Lycopene was solubilized in toluene and aqueous Tween 40, and then oxidized by incubating at $37^{\circ}C$ under atmospheric oxygen. Acidic compound was produced by autoxidation of lycopene. Retention time, UV-Vis spectra and mass spectra of the acidic compound were identical to the standard acycloretinoic acid. Thus, acycloretinoic acid was confirmed to occur in vitro under oxidation condition of lycopene.

• Journal of Nutrition and Health
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• v.25 no.5
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• pp.389-396
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• 1992

Provitamin A carotenoids($\alpha$- $\beta$-carotene lutein capsanthin) cintents in various red pepper and red pepper products were analyzed by HPLC and UV/VIS spectroscopy. The amounts of $\beta$-carotene and capsanthin were at its highest in powdered red pepper and lutein in red pepper leaves. There are little $\alpha$-carotene present in all samples analyzed. So vitamin A activity was calculated only from $\beta$-carotene content. Capsanthin and $\beta$-carotene contents of red pepper were higher than those of green pepper whereas lutein content of red pepper was lower than that of green pepper. whereas lutein content of red pepper was lower than that of green pepper. Vitamin A activity from colorimetric analysis was higher than that from chromatographic method and results were not generally in accordance with the vitamin A data presented in current food composition tables. Vitamin A activities in retinol equivalent(R. E. ) of green pepper red pepper powdered red pepper fermented red pepper paste and red pepper leaves were 70, 570, 1, 340, 140, 980 R. E respectively.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.989-996
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• 2007

In this study, abiotic transformation of 1-naphthol(1-NP) via oxidative-coupling reaction and its reaction products were investigated in the presence of Mn oxides. The reaction products were characterized for their relative polarity using solvent extraction experiment and reverse-phase HPLC, and for structure using CCMS and LC/MS, and for absorption characteristics using UV-Vis spectrometry. The reaction products present in aqueous phase were more polar than parent naphthol and comprised of 1,4-naphthoquinon(1,4-NPQ) and oligomers such as dimers and trimers. Hydrophilic component present in water phase after solvent$(CH_2Cl_2)$ extractions was identified as naphthol polymerized products having molecular weight(m/z) ranging from 400 to 2,000, and showed similar UV-Vis. absorption characteristics to that of foil fulvic acid. Transformation of 1,4-NPQ, which is non-reactive to Mn oxide, to the polymerized products via cross-coupling reaction in the presence of 1-NP was also verified. In this experimental conditions(20.5 mg/L, 1-NP, 2.5 g/L $MnO_2$, pH 5), the transformation of 1-NP into the oligomers and polymerized products were about 83% of initial 1-NP concentrations, and more than 30% of the reaction products was estimated to be water insoluble fractions, not extracted by $H_2O$ methanol. Results from this study suggest that Mn oxide-mediated treatment of naphthol contaminated soils can achieve risk reduction through the formation of oligomers md polymer precipitation.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3444-3450
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• 2013

Three phase hollow fiber-liquid phase microextraction (HF-LPME), which is faster, simpler and uses a more environmentally friendly sample-preparation technique, was developed for the analysis of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in human urine. For the effective simultaneous extraction/concentration of NSAIDs by three phase HF-LPME, parameters (such as extraction organic solvent, pH of donor/acceptor phase, stirring speed, salting-out effect, sample temperature, and extraction time) which influence the extraction efficiency were optimized. NSAIDs were extracted and concentrated from 4 mL of aqueous solution at pH 3 (donor phase) into dihexyl ether immobilized in the wall pores of a porous hollow fiber, and then extracted into the acceptor phase at pH 13 located in the lumen of the hollow fiber. After the extraction, 5 ${\mu}L$ of the acceptor phase was directly injected into the HPLC/UV system. Simultaneous chromatographic separation of seven NSAIDs was achieved on an Eclipse XDB-C18 (4.6 mm i.d. ${\times}$ 150 mm length, 5 ${\mu}m$ particle size) column using isocratic elution with 0.1% formic acid and methanol (30:70) at a HPLC-UV/Vis system. Under optimized conditions (extraction solvent, dihexyl ether; $pH_{donor}$, 3; $pH_{acceptor}$, 13; stirring speed, 1500 rpm; NaCl salt, 10%; sample temperature, $60^{\circ}C$; and extraction time, 45 min), enrichment factors (EF) were between 59 and 260. The limit of detection (LOD) and limit of quantitation (LOQ) in the spiked urine matrix were in the concentration range of 5-15 ng/mL and 15-45 ng/mL, respectively. The relative recovery and precision obtained were between 58 and 136% and below 15.7% RSD, respectively. The calibration curve was linear within the range of 0.015-0.96 ng/mL with the square of the correlation coefficient being more than 0.997. The established method can be used to analyse of NSAIDs of low concentration (ng/mL) in urine.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.48-48
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• 2021

This study was carried out to investigating quality and nutritional traits of melon genetic resources. It could provide important baseline data in breeding for increased β-Carotene, cucumisin content thereby increasing the marketability of melon. To this end, we have examined some fruit morphological traits and β-Carotene, cucumisin content of 163 genetic resources. The morphological characters were recorded on the field and inside laboratory and nutritional contents for β-carotene, cucumisin was measured using spectrophotomertic and HPLC methods. Melon fruits have shown a diverse morphological characters. Green and white is dominant for fruit skin color and round and oval-shape is dominant for form in the entire collections. The β-carotene content varied between 0.5 and 233.6mg/kg, 0.7 and 226.5mg/kg, 0.4 and 189.0 mg/kg using UV-Vis and microplated reader instruments, HPLC respectively. The high β-carotene contents were characterized five melon fruit originated from South Africa, Uzbekistan, Albania, France. The cucumisin content varied between 0.3 and 33.5 unit/mg, 0.29 and 32.1unit/mg using UV-Vis and microplated reader instruments, respectively.

• Analytical Science and Technology
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• v.29 no.6
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• pp.277-282
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• 2016

British Pharmacopoeia (BP 2013), the United States Pharmacopoeia (USP 39) and the Korean Pharmacopoeia (KP XI) contain monographs for the quality control of raw diosmin using high performance liquid chromatography (HPLC). However, official monographs detailing pharmaceutical formulations for diosmin are not available in foreign pharmacopoeias. In the KP XI, ultraviolet-visible (UV-Vis) spectroscopy-which is less specific than HPLC-is reported for the testing of diosmin capsules. In this study, we present an alternative HPLC assay for such testing that is more specific than UV-Vis methods. Method validation was performed to determine linearity, precision, accuracy, system suitability, and robustness. The linearity of calibration curves in the desired concentration range was high ($r^2$>0.999), while the RSDs for intra- and inter-day precision were 0.15-0.29 % and 1.05-1.74%, respectively. Accuracies ranged from 101.2-103.2 %, while the retention time and peak area RSDs were 0.37 % and 0.06 %, respectively. Additionally, the plate number and asymmetry factor values for diosmin were 3591.293 and 1.35, respectively. Since the intermediate-precision and robustness of the assay were satisfactory, this method will be a valuable addition to the Korean Pharmacopoeia (KP XI).

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.762-769
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• 2002

As a preliminary test for defining intact yellow croaker pigment, the pigment was analyzed by column chromatography and UV-vis spectrophotometry. All maximum absorbance wavelengths commonly showed three maximum absorbance ranges, similar to those of carotenoid, suggesting that the tested pigment may be carotenoid. We detected total six peak RT values in the chromatogram through PDA-HPLC under gradient mode (behavior A at 10% for initial 2 min and changed to behavior B for 60 min). Most pigments were detected at the peak with 3.27 RT value. Because seven peaks were detected under gradient mode and three under isocratic mode [methanol : methylene chloride (90 : 10, v/v)], gradient mode was determined to be more appropriate for quantitative analysis. By the comparison test of RT values among yellow pigment in croakers and reference pigments, such as zeaxanthine, ${\beta}-cryptoxanthine$, ${\beta}-carotene$, and astaxanthin, only ${\beta}-cryptoxanthine$ was detected in the white croaker, whereas such pigment of yellow croaker having RT value of 31.02 was not detected. Therefore, RT value was found to be applicable for detecting adulterated croaker.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.6
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• pp.827-836
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• 2013

Indigotin, indirubin, berberine, palmatine, alizarin, and purpurin are major pigments of indigo plant, Phellodendron bark, and madder. The six pigments were examined using the HPLC-DAD-MS instrument for the purpose of the simultaneous detection of the pigments in a single sample run. The HPLC-DAD-MS method examined the individual pigment solutions in DMSO, a solution containing 6 pigments, and the DMSO extract of the silk dyed with a dye solution of 5 pigments excluding indirubin. The retention times of the HPLC chromatograms, ${\lambda}_{max}$ of the uv-vis absorption bands in the DAD analyses, and the molecular ions detected for the compound peaks in the MSD analyses were consistent throughout the analyses of individual pigment solutions, mixed pigment solutions, and dye extracted from silk dyeing. The developed instrumental method of the simultaneous detection of six pigments can identify dye in an exhumed textile if the textile is dyed using any one (or multiple) pigments of indigo, Phellodendron bark, or madder plant.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.294-299
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• 2014

The simultaneous determination of platyphylloside, aceroside and betulin was established for the quality control of Betula platyphylla bark using a high performance liquid chromatography and diode-array UV/Vis detector (HPLC-DAD). Separation and quantification were successfully achieved with a INNO C18 column ($5{\mu}m$, 4.6 mm $I.D.{\times}150mm$) by gradient elution of a mixture of methanol and water at a flow rate of 1.0 ml/min. Validation of the developed method was performed by various factor such as linearity, specificity, precision, accuracy, system suitability and stability. This method was successfully applied to the determination of contents of platyphylloside, aceroside VIII and betulin in three batches of Betula platyphylla bark extract. These results suggest that the developed HPLC method is simple, effective and could be utilized as a quality control method for Betula platyphylla bark products.