• Proceedings of the PSK Conference
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• 2001.10a
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• pp.315.2-315.2
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• 2001

• 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.

• Analytical Science and Technology
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• v.26 no.2
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• pp.142-153
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• 2013

A new, rapid, and simple analytical method was developed and validated using high performance liquid chromatograph-photodiode array detector (HPLC-PAD) for the determination of lepimectin residues in agricultural commodities. The lepimectin residues in samples were extracted with methanol, partitioned with dichloromethane, and then purified with glass column filled with subsequently to aminopropyl ($NH_2$) solid phase extraction (SPE) cartridge. The purified samples were detected using HPLC-PAD. Correlation coefficient ($R^2$) of both lepimectin $A_3$ and $A_4$ solutions were 0.9999. The method was validated using cucumber spiked with lepimectin at 0.02 and 0.2 mg/kg and pepper, mandarin, hulled rice, potato, soybean at 0.02 and 0.5 mg/kg. Average recoveries were 76.0~114.8% with relative standard deviation less than 10%, and limit of detection (LOD) and limit of quantification (LOQ) were 0.005 and 0.01 mg/kg, respectively. The result of recoveries and overall coefficient of variation of a laboratory results in Gwangju regional KFDA and Daejeon regional KFDA was followed with Codex guideline (CAC/GL 40). Therefore, developed method in this study is accurate, rapid, and appropriate for lepimectin determination and will be used to keep safety of lepimectin residues in agricultural products.

• Herbal Formula Science
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• v.18 no.2
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• pp.251-257
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• 2010

Objectives : To develop and validate High-performance liquid chromatography-photodiode array methods for simultaneous determination of two constituents in Oryeong-san(ORS). Methods : Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array(PDA) detection at 280 nm, were used for quantification of the two marker components of ORS. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was $H_2O$ and solvent B was acetonitrile. Results : Calibration curves were acquired with correlation coefficient ($r^2$)>0.9999, and the relative standard deviation(RSD) values(%) for intra- and inter-day precision were not exceed 1.0%. The recovery rate of each compound was in the range of 93.01-104.16%, with an RSD less than 2.0%. The contents of two compounds in ORS were 1.10-3.72 mg/g. Conclusions : The established HPLC method will be helpful to improve quality control of ORS.

• The Journal of Korean Medicine
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• v.31 no.6
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• pp.8-15
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• 2010

Objectives: We investigated to develop and validate HPLC-PDA methods for simultaneous determination of eight constituents in Galgeun-tang (GGT). Methods: Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 230 nm, 254 nm, and 280 nm, were used for quantification of the eight marker components of GGT. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. Results: Calibration curves were acquired with $r^2$ > 0.9999, and the relative standard deviation (RSD) values (%) for intra- and inter-day precision were less than 3.0%. The recovery rate of each component was in the range of 87.33-101.38%, with an RSD less than 7.0%. The contents of the eight components in GGT were 1.98-12.17 mg/g. Conclusions: The established method will be applied for the quantification of marker components in GGT.

• The Korea Journal of Herbology
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• v.25 no.3
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• pp.65-71
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• 2010

Objectives：To develop and validate HPLC-PDA methods for simultaneous determination of seven constituents in Samchulkunbi-tang (SKT). Additionally, we investigated the cytotoxicity against BEAS-2B cell line and splenocytes of SKT. Methods：Reverse-phase chromatography using a Gemini $C_{18}$ column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 230, 254 and 280 nm, were used for quantification of the three marker components of SKT. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. The cytotoxicity of SKT were measured by the CCK-8 assay method. Results：Calibration curves were acquired with $r^2$>0.9999, and the relative standard deviation (RSD) values (%) for intra- and inter-day precision were less than 6.0%. The recovery rate of each compound was in the range of 86.89-109.78%, with an RSD less than 4.0%. The contents of seven compounds in SKT were 1.39-6.84 mg/g. SKT had no cytotoxicity effect at 50-200 ${\mu}g$/mL concentrations. Conclusions：The established method will be helpful to improve quality control and in vitro efficacy study of SKT.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2663-2670
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• 2013

The purpose of stability testing is to provide evidence about how the quality of a drug varies with time under the influence of a variety of environmental factors. In this study, erythropoietin (EPO) was analyzed under different pH (pH 3 and pH 9) and temperature ($25^{\circ}C$ and $40^{\circ}C$) conditions according to current Good Manufacturing Practice (cGMP) and International Conference on Harmonisation (ICH) guidelines. The molecular weight difference between intact EPO and deglycosylated EPO was determined by SDS-PAGE, and aggregated forms of EPO under thermal stress and high-pH conditions were investigated by size exclusion chromatography. High pH and high temperature induced increases in dimer and high molecular weight aggregate forms of EPO. UPLC-ESI-TOF-MS was applied to analyze the changed modification sites on EPO. Further, normal-phase high-performance liquid chromatography was performed to identify proposed glycan structures and high pH anion exchange chromatography was carried out to investigate any change in carbohydrate composition. The results demonstrated that there were no changes in modification sites or the glycan structure under severe conditions; however, the number of dimers and aggregates increased at $40^{\circ}C$ and pH 9, respectively.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1629-1637
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• 2007

An immunochromatography (ICG) strip test using a nanocolloidal gold-antibody probe was developed and optimized for the rapid detection of aflatoxin B1 (AFB1). A monoclonal antibody specific to AFB1 was produced from the cloned hybridoma cell (AF78), coupled with nanocolloidal gold, and distributed on the conjugate pad of the ICG strip test. The visual detection limit of the ICG strip test was 0.5 ng/ml, and this method showed a cross-reaction to aflatoxin B2, G1, and G2. In total, 172 grain and feed samples were collected and analyzed by both the ICG strip test and HPLC. The results of the ICG strip test showed a good agreement with those obtained by HPLC. These results indicated that the ICG strip test has a potential use as a rapid and cost-effective screening tool for the determination of AFB1 in real samples and could be applied to the preliminary screening of mycotoxin in food and agricultural products, generating results within 15 min without complicated steps.

• Journal of Microbiology and Biotechnology
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• v.19 no.1
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• pp.83-92
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• 2009

Individual immunochromatographic assays (ICG) for ochratoxin A (OTA) and zearalenone (ZEA) were optimized and used in the development of a one-step simultaneous immunochromatographic assay (OS-ICG) for the rapid multianalysis of two mycotoxins in corn samples. The nitrocellulose membrane of the OS-ICG was treated with OTA-bovine serum albumin (BSA), ZEA-ovalbumin (OVA), and anti-mouse IgG in the OTA test, ZEA test, and control zones, respectively. Monoclonal antibody-gold conjugates (OTA3 MAb-gold and ZEA2C5 MAb-gold) were sprayed onto the conjugate pad. The visual detection limits were 2.5 and 5 ng/ml for OTA and ZEA, respectively, and the results were obtained within 15 min after starting the analysis. An efficient, simple, and rapid extraction method using 30% MeOH/PBS was established and validated by analyzing the corn samples spiked with OTA/ZEA mixtures (0/0, 5/10, 10/20, and $20/30\;{\mu}g/kg$). The cut-off values of the OS-ICG for the spiked corn were 5 and $10\;{\mu}g/kg$ for OTA and ZEA, respectively. Natural corn samples were analyzed by OS-ICG, direct competitive enzyme-linked immunosorbent assay (DC-ELISA), and HPLC. Results of the OS-ICG were in good agreement with those obtained by DC-ELISA and HPLC. The developed OS-ICG offers a rapid, easy-to-use, and portable analytical system and can be used as a convenient qualitative tool for the on-site simultaneous determination of OTA and ZEA in cereals, food, and agricultural products in one analytical cycle.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.740-746
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• 2014

The unripe fruit of cudrania tricuspidata was extracted with 50% ethanol. The crude water-soluble extracts were separated by liquid-liquid separation with n-hexane, ethyl acetate and butanol followed by precipitation with ethanol, and then the water-soluble polysaccharide (F1) was isolated by the fractionation through gel permeation chromatography using preparative PLaquagel-OH column with water. The structure was characterized by monosaccharide composition with HPAEC-PAD, methylation analysis with GC-MS, FT-IR and HPLC. According to the data, F1 was com posed of glucose (22.84 mM), galactose (13.75 mM), arabinose (45.87 mM), xylose (7.49 mM). It was revealed which uronic acid and acetyl group were not attached in F1. And it is constituted of 1-linked arabinose, 1,4-linked arabinose, 1,3-linked glucose, 1,4-linked galactose, 1,4-linked glucose, 1,3,6-linked galactose, 1,3,6-linked glucose and the ratio was showed 1.1 : 1.0 : 4.9 : 7.5 : 3.0 : 3.1 : 1.4 : 1.5.