• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.5
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• pp.369-371
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• 2003

Cyanidin 3-glucoside (C3G) content contained in the grains of blackish purple rice varieties, Heugjinjubyeo, Kilimheugmi, Heugnambyeo, Sanghaehy-anghyeolla, and the progenies derived from their crosses was evaluated by HPLC and UV-Vis spectroscopy. C3G content was higher in the range of 10-30% by using UV-Vis method compared to HPLC method. A significant linear relationship was, however, observed between two analytical methods. The correlation coefficient was 0.98. Thus, this results suggested that it would be able to use UV-Vis spectroscopy to determine C3G content which does not demanded precise value like selection.

• Analytical Science and Technology
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• v.28 no.2
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• pp.112-116
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• 2015

Extraction of quaternary ammonium compounds (choline and betaine) from plant samples (spinach) using ion exchange resin (AG1, OH⁻ form) is a very simple and inexpensive approach. However, it is very hard to determine amounts of choline and betaine simultaneously using high-performance liquid chromatography-ultraviolet (HPLC-UV) detection. Unlike choline, betaine has low molar absorptivity in UV-visible (UV-Vis) region, which makes it difficult to carry out UV-Vis detection of betaine. The mixture of quaternary ammonium compounds (choline and betaine) was derivatized using 2-bromo acetophenone as a derivatizing agent. As a result, choline did not react with the derivatizing agent, whereas betaine formed a betaine derivative. This betaine derivative exhibited detectable UV absorption with baseline separation between choline and the betaine derivative. Thus, with this method, choline and betaine can be determined simultaneously by using the HPLCUV method through one-step derivatization, which is an easy, sensitive, and reliable method.

• Analytical Science and Technology
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• v.33 no.3
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• pp.115-124
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• 2020

Marker pens belong to school things that are controlled by the regulation system called safety confirmation under special act on the safety of products for children with the formaldehyde criteria of 20 mg/kg. With nine marker pens available commercially, formaldehyde in marker pen ink was analyzed by present test standard where marking on a fabric swatch with a pen and extracting the swatch in water and derivatization with Nash reagent followed by UV/Vis spectrophotometeric measurement (Nash-UV/Vis method), giving not detected results or a false positive result in case of a colored water extract. However, the contents of formaldehyde in ink of nine marker pens were determinded to range between 3.2 ~ 93.2 mg/kg with three results above the safety criteria of 20 mg/kg by HPLC/DAD measurements on DNPH derivatives of formaldehyde (DNPH-HPLC/DAD method) in ink dissolved directly in water using an ultrasonic bath. Therefore, the DNPH-HPLC/DAD method with the extraction of ultrasonic dissolving ink in water is proposed as a proper method for analyzing formaldehyde in ink. The proposed method has advantages of lower detection limit and accuracy with colored extracts as well as a simple and fast extraction. The accuracy and precision of this method was estimated to be 90.1 ~ 105.4 % and 0.6 ~ 3.3 %, respectively by spiking tests in the ranges of 20 mg/kg and 40 mg/kg using matrixes such as highlighter pen ink, board marker ink, chalk marker pen ink and painter marker ink.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.306-310
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• 2010

Petroleum visible markers (dye) have been used to distinguish different fuel classes and to prevent illegal mixing. It is difficult to recognize the real color of visible marker when the small amount of petroleum product was mixed in another fuel oil. In this study, we determined the two wavelengths (370 nm, 645 nm) which detect all Korean petroleum visible marker using UV/Vis spectrophotometer. Then we analyzed the visible marker using high performance liquid chromatography (HPLC) in two wavelength detectors. Also, we optimized the analytic method for petroleum visible marker in illegal mixed fuel oil.

• Analytical Science and Technology
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• v.26 no.1
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• pp.19-26
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• 2013

Gibberllic acid ($GA_3$) is one of gibberellins (GAs) that are a class of plant growth hormones that exert profound and diverse effects on plant growth and development. $GA_3$ is essentially non-UV absorbing and is difficult to assay by UV-detector. For effective extraction of gibberellic acid from fruits by using liquid-liquid extraction, optimized pH and extraction solvent were established. The selective and sensitive derivative of $GA_3$ for HPLC/UV-vis was derivatized using phenacyl bromide, and the experimental factors, including reaction time, reaction temperature and amount of derivatizing reagent and base were investigated for the effective synthesis. The derivatized $GA_3$ with phenacyl bromide was effectively analyzed by HPLC/UV-vis. The structure of derivatized $GA_3$ was confirmed by HPLC/ESI-MS. For apple, LOD and LOQ were 0.008 mg/kg and 0.027 mg/kg, respectively. For pear, LOD and LOQ were 0.003 mg/kg, 0.012 mg/kg, respectively. The established method can be applied to more effective analysis of $GA_3$ from plant and food.

• Analytical Science and Technology
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• v.13 no.3
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• pp.282-290
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• 2000

In this study, polymer additives were extracted and separated by Soxhlet extraction method and the dissolution-precipitation method from a polycarbonate (optical grade) which completely absorbed UV light below 390 nm. Analytical techniques such as UV-Vis spectroscopy, FT-IR, and HPLC were applied to analyze additives in polycarbonate. Separated materials from the polycarbonate may be a complex mixture containing additives such as UV stabilizer, antioxidants (primary and secondary), monomers, and oligomers. Several compounds such as bisphenol A, Irganox 1010, and Cyasorb UV-5411 were identified by chromatograms and UV spectra obtained from RP HPLC analysis using Bondapak $C_{18}$ column, methanol mobile phase, and a photodiode array (PDA) detector. Also, the content of UV-5411 in the polycarbonate was about 0.12 wt% by a quantitative analysis through UV spectroscopy.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2787-2794
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• 2013

Cholesterol and cholesterol oxidation products (COPs) may accumulate in foods of animal origin during processing or storage. An effective and sensitive analytical method was developed by increasing the UV absorption of compounds through derivatization by attaching a chromophore to the functional groups of cholesterols (cholesterol, 20-hydroxycholesterol, 7-ketocholesterol, cholestane-$3{\beta}$-$5{\alpha}$-$6{\beta}$-triol, 25-hydroxycholesterol, and $5,6{\alpha}$-epoxycholesterol). The influences of the reaction time, volume of reaction solvent, amounts of derivatizing reagent, and extraction solvents were investigated, as they may influence the reaction and extraction yield. The derivatized COPs were analyzed simultaneously on a C18 column (2.1 mm i.d. ${\times}$ 100 mm length, $3.5{\mu}m$ particle size) using a gradient elution with water and acetonitrile. The derivatized COPs showed increased sensitivity and selectivity in HPLC/UV-Vis. The LOD and LOQ were in the concentration ranges of 0.018-0.55 mg/kg and 0.059-1.84 mg/kg from the powdered milk. And the accuracy and precision were 78.1-116.7% and 1.1-9.9%, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.95-100
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• 2006

Sesamin and sesamolin, antioxidant lipidsoluble lignan compounds, are abundant in sesame (Sesamum indicum L.) seed oil and provide oxidative stability of oil related to sesame quality. The sesamin and sesamolin contents of 403 sesame land races of Korea were determined by HPLC analysis of methanol extract (HPLC value), and their total lignan content was compared with those by using UV-Vis spectrophotometric analysis (UV method) of methanol (UV-MeOH value) and hexane (UV-Hexane value) extracts. HPLC values of total lignan content were strongly associated with UV-Hexane (r=0.705**) and UV-MeOH (r=0.811**) values. The UV values from both the extracts were 3.8-4.7 times higher than those of HPLC values. Lignan content was overestimated by UV method because total compounds in the mixture solution were quantified by absorbing at the same ultraviolet wavelength as in HPLC method. UV method could more rapidly analyze small amount of sample with higher sensitivity of detection than HPLC method. Average contents of lignans in sesame germplasm evaluated in this study were $2.09{\pm}1.02mg/g$ of sesamin, and $1.65{\pm}0.61mg/g$ of sesamolin, respectively, showing significant variation for lignan components. The results showed that UV method for the determination of sesamin and sesamolin could be practically used as a faster and easier method than HPLC by using the regression equations developed in this study.

• Journal of the Korean Applied Science and Technology
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• v.15 no.3
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• pp.27-31
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• 1998

Antioxodative substances in Mulberry leaves were examined. Antioxidative substances in Mulberry leaves were extracted by 80% methanol agueous solution. Antioxidative activity of extract was determined by examining hydrogen donating ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the inhibitory effect on the formation of the peroxide from Linoleic acid in the test tube at $50^{\circ}C$. Antioxidative substance were, then, separated and indentified by thin layer chromatography(TLC), UV-Vis spectrum and High performance liquid chromatography(HPLC) methods. Hydrogen donating ability on DPPH and antioxidative ability on linoleic acid of the extracted antioxidative substance were higher than those of 100ppm butylated hydroxy toluene(BHT). The extracted antioxidative substances were separated by TLC using ethylacetate : chloroform : formic acid : water(8 : 1 : 1 : 1 v/v) as a solvent, and a spot at Rf=0.35 was detected. The spot was scraped from the plate, and extrated by methanol. The extract was analyzed by UV-Vis spetra and HPLC, and chlorogenic acid was identified as a antioxidative substance.

• Journal of Pharmaceutical Investigation
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• v.24 no.1
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• pp.29-32
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• 1994

In order to improve the sensitivity of the current assay methods of selenium in dried-yeast preparations, atomic absorption spectrophotometry (AAS), high performance liquid chromatography (HPLC) and UV-Vis spectrophotometry were employed. The sample was prepared with the digestion by acid mixture of hydrochloric acid, nitric acid and perchloric acid after elimination of ether-soluble substances. The range of quantitation of selenium was $1.0{\sim}6.0\;{\mu}g/ml$ by UV-Vis spectrophotometry, $5.0{\sim}20.0\;{\mu}g/ml$ by HPLC and $0.03{\sim}0.10\;{\mu}g/ml$ by AAS.