• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.189-197
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• 1994

Analytic methods for Cr(VI) level in industrial hygienic field were suggested by the National Institute for Occupational Safety and Health(NIOSH method 7600, 7604). There were growing needs for measurement of Cr(III) and Cr(VI) levels simultaneously. Two analytical methods were suggested to determine Cr(III) and Cr(VI) levels simultaneously. The one is method by using reversed phase high peformance liquid chromatography(HPLC) and the other is by using ion exchange HPLC. The purpose of this work was to evaluate the usefulness of these two analytic methods. For the difference of ionic charges of Cr(III)-ethylendiamine tetraacetic acid(EDTA) chelate and $CrO_4{^-2}$, we could detect them simultaneously by ion exchange HPLC. Also, we attempted to determine the levels of Cr(III) and Cr(VI) chelated with sodium diethyldithiocarbamate(NaDDTC) by using reversed phase HPLC. The confirmation of Cr(III) and Cr(VI) were checked by fraction collector and nameless atomic absorption spectrometer. The optimal conditions for the formation of Cr(III)-EDTA chelate were two hours incubation period with pH 5. Cr(III)-EDTA and Cr(VI) in EDTA solution were successfully separated by anion exchange column using $Na_2CO_3/NaOH$ mixture as mobile phase. Peaks of Cr(III)-EDTA and Cr(VI) in EDTA were identified at 5 minutes and 7 minutes of retention time respectively by the ion exchange HPLC. The formation of Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates were twelve hours incubation period. Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates were separated by reversed phase column using methanol and water mixture as mobile phase. Peaks of Cr(VI)NaDDTC and Cr(III)-NaDDTC chelates were identified at 13 minutes and 26 minutes of retention time respectively by the reversed phase HPLC. Due to reduction of Cr(VI) to Cr(III), it seems to be not suitable for simultaneous determination of Cr(III)-NaDDTC and Cr(VI)-NaDDTC chelates by reversed phase HPLS. Simultaneos determination of Cr(III) and Cr(VI) by ion exchange HPLC was more accurate and simple method.

• Natural Product Sciences
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• v.26 no.3
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• pp.236-243
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• 2020

Salvia plebeia R. Br. is a plant which has been used as an edible crop and traditional medicine in Asian countries. In this study, HPLC-PDA analysis and countercurrent chromatography (CCC) coupled with reversed-phase (RP) HPLC method were applied to isolate ten isolates from 3.3 g of n-butanol soluble extract from hot-water extract of S. plebeia. The use of CCC enabled us to efficiently fractionate the starting material with less sample loss and facilitate the isolation of compounds from S. plebeia extract using RP-HPLC. The isolates were determined to be caffeic acid (1), 6-hydroxyluteolin 7-O-β-D-glucoside (2), eudebeiolide B (3), (R)-rosmarinic acid (4), homoplantaginin (5), eudebeiolide D (6), plebeiolide C (7), salpleflavone (8), eupafolin (9) and hispidulin (10) based on the spectroscopic evidence.

• KSBB Journal
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• v.18 no.5
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• pp.408-411
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• 2003

By reversed-phase high-performance liquid chromatography, the extraction and separation of glabridin by from licoricce root was performed in this work. The column efficiencies and resolutions of glabridin were investigated with mobile phase composition on the reversed-phase chromatographic system. The glabridin collected from licorice root was identified by LC/MS. The mobile phase used to extract glabridin were composed of ethanol, methanol, acetone, and ethyl acetate. For one-hour ultrasonic extraction with solvent of ethyl acetate, the favorable content of glabridin was obtained as 1.26g/kg. The glabridin was well separated in the mobile phase composition of 50/50 vol. % (acetonitrile/water).

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.339-346
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• 2006

Semi-micro-HPLC using a column-switching technique was developed for simultaneous determination of vitamin A and E contents in infant formula. Vitamin A and E were extracted by PDA - HPLC with reversed phase column using organic solvent and their contents in Certified Reference Material (CRM) and infant formula were determined and compared with hydrolysis method and rapid extraction. Developed method has many advantages of simple and rapid sample preparation and simultaneous determination of vitamin A and E by micro-HPLC using reversed phase column.

• The Korean Journal of Physiology
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• v.24 no.2
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• pp.363-375
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• 1990

The present investigation was performed to purify bombesin-like immunoreactivity (BBS-LI) from the skin of frogs, B. orientalis inhabiting Korea. For extraction of BBS-LI, the fresh skin of 360 g from frogs was immersed in 1,800 ml of 100% methanol and then kept at $4^{\circ}C$ for 5 days. BBS-LI was partially purified by liquid chromatography using an alkaline alumina column followed by a Sephadex G-10 column. BBS-LI was further purified by using sequential HPLC of reversed phase C18 preparation, gel permeation, SP-ion exchange and reversed phase C18 analysis. BBS-LI in fractions of each step was monitored by radioimmunoassay for which bombesin antiserum with a titer of 1 : 188,800 was raised in a guinea pig. Eventually, two different BBS-LI were successfully purified and each BBS-LI showed the following character. 1) BBS-LI was well separated into two peaks in SP-ion exchange HPLC. One (BBS-LI-K1) bound to the column while the other (BBS-LI-K2) did not. 2) BBS-LI-K1, 73.8% of total BBS-LI, was not differentiated from synthetic bombesin in reversed phase C18 analytical and gel permeation HPLC. 3) BBS-LI-K2, 26.2% of total BBS-LI, eluted later than synthetic bombesin in reversed phase C18 analytical HPLC, but it eluted with a retention time identical to that of synthetic bombesin in gel permeation HPLC. 4) The two forms of BBS-LI and synthetic bombesin identically stimulated gastrin release and pancreatic exocrine secretion including volume, protein output and amylase output in anesthetized rats. It is concluded from the above results that the skin of B. orientalis contains two different forms of BBS-LI which are very identical to bombesin immunologically and biologically. In comparison with synthetic bombesin containing 14 amino acid residues, the major form shows quite similar pattern in all HPLC used in the present study, but the minor form exhibits quite different pattern in SP-ion exchange and reversed phase C18 analytical HPLG.

• Toxicological Research
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• v.35 no.2
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• pp.161-165
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• 2019

Cysteamine has been used in cosmetics as an antioxidant, a hair straightening agent, and a hair waving agent. However, recent studies indicate that cysteamine can act as an allergen to hairdressers. The objective of this study was to develop and validate a simple and effective reversed-phase high-performance liquid chromatography (RP-HPLC) method for the measurement of cysteamine and its dimer, cystamine. Sodium 1-heptanesulfonate (NaHpSO) was used as an ion-pairing agent to improve chromatographic performance. Separation was performed on a Gemini C18 column ($250mm{\times}4.6mm$, $5{\mu}m$ particle size) using a mobile phase composed of 85:15 (v/v) 4 mM NaHpSO in 0.1% phosphoric acid:acetonitrile. UV absorbance was monitored at 215 nm. The RP-HPLC method developed in this study was validated for specificity, linearity, limit of detection, limit of quantitation, precision, accuracy, and recovery. Cysteamine and cystamine were chromatographically resolved from other reducing agents such as thioglycolic acid and cysteine. Extraction using water and chloroform resulted in the recovery for cysteamine and cystamine ranging from 100.2-102.7% and 90.6-98.7%, respectively. This validated RP-HPLC method would be useful for quality control and monitoring of cysteamine and cystamine in cosmetics.

• Journal of the Korean Applied Science and Technology
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• v.22 no.4
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• pp.339-348
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• 2005

On the analysis of triacylglycerol (TG) from the kernels of Acanthopanax sessiliflorus by reversed phase-HPLC, it was separated into three main fractions of PN 44, 46 and 48, according to partition number (PN). On the contrary, it could be clearly classified into seven fractions of SMM, MMM, SMD, MMD, SDD, MDD and MDT by silver ion-HPLC by the number of double bond in the acyl chains of TG species. But resolution of so-called critical pairs of TG molecular species such as molecular pairs of $P_eLL$ $[C_{18:1{\omega}12}/(C_{18:2{\omega}6)2}]$ and OLL $[C_{18:1{\omega}9}/(C_{18:2{\omega}6)2}]$ and OOL $[(C_{18:1{\omega}9)2}/C_{18:2{\omega}6]$, and $P_eP_eL$ $[(C_{18:2{\omega}12)2}/C_{18:1{\omega}6]$ was not achieved $(P_e;$ petroselinic acid, L; linoleic acid, O; oleic acid). On the other hand, TG extracted from Aralia continentalis kernels were also fractionated into seven groups of SSM, SMM, MMM, SMD, MMD, SDD and MDD (S; saturated acid, M; monoenoic acid, D; dienoic acid) by silver ion-HPLC, although it's were classified into three groups of PN 44, 46 and 48 by reversed phase-HPLC. The fractions of SMM, MMM, MMD and MDD were divided into two subfractions, respectively; the fractions of SMM, MMM, MMD and MDD were resolved into the subfraction of $PP_e/P_e$ and POO (critical pairs from each other), that of $P_e/P_e/P_e$ and OOO, that of $P_e/P_e/L$ and OOL, and that of $P_e/L/L$ and OLL.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.87-95
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• 2020

In this study, we separated and purified lipase inhibitory peptide from fermented milk by Lactobacillus plantarum Q180 with the aim of developing a new functional anti-lipase activity yogurt product. L. plantarum 180 was inoculated into 10% reconstituted skimmed milk and incubated at 37℃ until the pH of the culture reached pH 4.4. The lipase activity was measured using porcine pancreatic lipase. The lipase inhibitory peptides were gradually isolated by ultrafiltration, reversed phase column chromatography (RPC), reversed phase high-performance liquid chromatography (RP-HPLC), and gel permeation high-performance liquid chromatography (GP-HPLC) from the fermented milk by L. plantarum Q180. An ODS-AQ column was used for the RPC, a Vydac C18 column for the RP-HPLC, and a Superdex Peptide HR column for the GP-HPLC. The peptide was composed of Asp, Thr, Ile, Ser, Ala, and Gln, and the anti-lipase activity (IC₅₀) was 2,817 ㎍/mL.

• The Korea Journal of Herbology
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• v.23 no.4
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• pp.171-177
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• 2008

Objectives: This study presents a reversed-phase high-performance liquid chromatography- pulsed amperometric detection(RP-HPLC-PAD) method for the determination of puerarin and daidzin in Puerariae Radix extract and Chinese medicinal preparations. Methods: Chromatographic separation was performed using a 10% acetonitrile with a reversed-phase column(Unison UK-C18, $100mm{\times}2.0mm$ I.D.; $3{\mu}m$). The analyses were detected by pulsed amperometric detector(PAD) in alkaline conditions by combining with post-column NaOH solution. Geniposide was used as an internal standard. Results: The limit of detection(S/N=3) and the limit of quantification(S/N=10) were 0.025 ng, 0.075 ng for puerarin, and 0.05 ng, 0.15 ng for daidzin, respectively. The intra- and inter-day precisions(RSDs) were less than 6.5% and average recoveries of puerarin were 99.7-101.3% and those of daidzin were 101.0-102.8%. Conclusions: According to above results, we developed a determination method for puerarin and daidzin in Puerariae Radix with high sensitivity and selectivitely.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.2
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• pp.161-164
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• 1991

A rapid and accurate method is described for the determination of nucleo-bases in rumen micro-organisms. A procedure to satisfactorily hydrolyse the micro-organisms involving reaction with a mixture of readily volatile organic acids (acetic and formic acids) under high pressure, is proposed, and optimal conditions for an analytical procedure with reversed phase HPLC is described. The following nucleobases contents (mmol/kg DM) of rumen micro-organisms were found: Adenine (Ade), 82.62; Guanine (Gua), 61.34; Cytosine (Cyt), 84.61; Thymine (Thy), 35.74; Uracil (Ura), 68.62; Hypoxanthine (Hxn), 13.06; Xanthine (Xn), 8.35. Total purine-N content (g/kg N) of rumen micro-organisms were 99.60. The nucleic acid N content (g/kg N) of microbial isolates were: RNA-N, 109.9; DNA-N, 50.9.