• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.1-6
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• 2006

Ionic liquids are receiving an upsurge of interest as 'green' solvents; primarily as replacements for conventional media in chemical processes. Although ionic liquids are rather 'young' modifier, their great potential in high-performance liquids chromatography (HPLC) has already been demonstrated. This review presents an overview of the applications of ionic liquids as mobile phase modifiers in HPLC.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.293-297
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• 2010

To prevent amnesic shellfish poisoning (ASP) resulting from the consumption of shellfish contaminated with domoic acid, the quantitative analysis of domoic acid is very important. We validated a high performance liquid chromatography (HPLC) method for accurate and precise quantification of domoic acid. A clear peak and the isolation of domoic acid resulted on injecting a 50% methanol extract of CRM-ASP-Mus-c mussel reference material using HPLC. The limit of detection of domoic acid under the established HPLC conditions was $0.10\;{\mu}g/g$, and the limit of quantification of the toxin under the same conditions was $0.25\;{\mu}g/g$. The intra-accuracy and precision for domoic acid in CRM-ASP-Mus-c were 90.7-95.7% and 0.28-22.25%, respectively. The inter-accuracy and precision for domoic acid were 89.1-97.1% and 1.7-4.1%, respectively. The mean recovery of domoic acid in methanol extracts from ten species of marine invertebrates was 88.6-1105.1%.

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.317-330
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• 2006

This study was conducted to develop the analytical method about simultaneous determination for synthetic antimicrobials in muscle by high performance liquid chromatography - mass selective detector (HPLC- MSD). Solid phase extraction (SPE), matrix solid phase dispersion (MSPD) and liquid-liquid extraction (LLE) have been adapted as pretreatment procedures for HPLC- MSD. Among various solvent tested, methanol was chosen for extraction of synthetic antimicrobials in muscles. For the optimized response, the values of various MS parameters including fragment voltage, drying gas flow, nebulizer pressure, drying gas temperature were verified. The average recovery rates using MSPD and SPE for muscles of bovine and pork were 78.9-127.1% and 78.3-121.7%, respectively. This method was verified the satisfactory performance for fourteen synthetic antimicrobials excepting carbadox in muscle of pork as detection limit of $0.05{\mu}g/g$ on API/ES SIM mode.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.286-290
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• 2012

Many diterpenoids from Siegesbeckia species (Compositae) and their anti-inflammatory actions have been examined. In this research, high-performance liquid chromatography-ultraviolet spectrophotometer (HPLC-UV) method was used to compare the quantitative level of kirenol (ent-pimarane-type diterpenoid) in the aerial parts of Korean S. glabrescens and S. pubescens and the Chinese Siegesbeckiae Herba. Fingerprints of the two HPLC chromatograms of Korean S. glabrescens and S. pubescens were similar, but considerably different from Chinese Siegesbeckiae Herba. The content of kirenol in S. pubescens ($16.51{\pm}0.10$ mg/ml dry weight as mean${\pm}$RSD) was higher than S. glabrescens ($13.48{\pm}0.12$ mg/g dry weight). These values were considerably higher than the Chinese Siegesbeckiae Herba ($1.55{\pm}0.74$ mg/g dry weight). Thin layer chromatography (TLC) analysis demonstrated the containing of kirenol in the three plant materials, but the presence of siegeskaurolic acid (entkaurane-type diterpenoid) only in the Chinese Siegesbeckiae Herba.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.13-19
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• 2001

A simple and rapid analytical method for the determination of tylosin in chicken, pork and muscle was established by High-Performance Liquid Chromatography(HPLC). Chicken, pork and beef muscle(5 g) were fortified by adding the $0.2{\mu}g/ml$ of standard tylosin and the drug was extracted from meats with 70% acetonitrile(ACN) and followed by liquid-liquid partition for clean-up procedure. Then $20{\mu}l$ portion of ACN elution was directly analyzed by HPLC with spectra 100 variable wavelength detector, and unfortified blank control were treated similarly. The average recovery rate of tylosin added to chicken, pork and beef muscle were $83{\pm}2.3$, $96{\pm}3.3$ and $92{\pm}1.6$(%) at the level 0.2 ppm, respectively. No tylosin residues in marketing meats. These results suggested that HPLC methodology could be acceptable for the extraction, determination and screening of tylosin residues in edible meats.

• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.251-257
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• 2004

Analytical methods were developed to determine cyclosulfamuron residues in soil, water, rice grain and straw using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. In these methods, cyclosulfamuron was extracted with aqueous $Na_2HPO_4$/acetone and acetone/methanol mixture from soil and rice samples respectively. Liquid-liquid partition coupled with ion-associated technique, Florisil column chromatography, and solid-phase extraction (SPE) were used to separate cyclosulfamuron from interfering co-extractives prior to HPLC analysis. For water sample, the residue was enriched in $C_{18}$-SPE cartridge, cleaned up in situ, and directly subjected to HPLC. Reverse-phase HPLC under ion-suppression was successfully applied to determine cyclo-sulfamuron in sample extracts with the detection at its ${\lambda}_{max}$ (254 nm). Recoveries from fortified samples averaged $87.8{\pm}7.1%$ (n=12), $97.3{\pm}7.2%$ (n=12), $90.8{\pm}6.6%$ (n=6), and $78.5{\pm}6.7%$ (n=6) for soil, water, rice grain and straw, respectively. Detection limits of the methods were 0.004 mg/kg, 0.001 mg/L, 0.01 mg/kg and 0.02 mg/kg for soil, water, rice grain and straw samples, respectively.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.178-183
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• 1997

A protease was purified from Bacillus subtilis CCKS-111 by ammonium sulfate treatment, DEAE-cellulose ion-exchange chromatography, Sephadex G-100 gel filtration and high performance liquid chromatography (HPLC). The specific activity of the purified enzyme was 24.3 unit/mg protein and the purification fold of enzyme was 50.6. Molecular weight of the purified enzyme estimated about 28,000 by HPLC gel filtration. The amino acid residues of this enzyme were 251.3 except threonine, serine and glycine. This result was similar to Bacillus subtilis subtilisin DY. From the first N-terminal amino acid to the 32th amino acid, the amino acid sequence was estimated after RP-HPLC elution. N-terminal and the 32th amino acids were alanine and aspartic acid. Alanine, serine, glycine and arginine were four major acids in the enzyme.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2666-2670
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• 2011

High-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) were used to identify five active components in the modified herbal decoction Bo-Yang-Hwan-O-Tang (mBHT), i.e., amygdalin, decursin, paeoniflorin, salvianolic acid B, and calycosin-7-O-${\beta}$-D-glycoside. These components were identified by comparing their retention times and mass spectra with those of reference compounds. The conditions of both analytical methods were optimized and validated. Sufficient separation of target analytes was achieved using a buffer consisting of 40 mM sodium borate and 60 mM sodium dodecylsulfate (SDS) containing 10% methanol (pH 9.5) at 250 nm for CE analysis and gradient elution with a water-methanol mobile phase and ultraviolet (UV) photodiode array detector (DAD) at 250 nm for HPLC analysis. The mBHT components were determined within 65 min by HPLC and 16 min by CE. All calibration curves showed high linearity (R > 0.999) within the ranges tested. Intra-day and inter-day precision were less than 1.6% and 1.8% for HPLC and 2.5% and 4.8% for CE, respectively. The accuracy of the methods ranged from 98.8% to 102.3% for HPLC and from 95.9% to 108.2% for CE.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.102-108
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• 2008

At the University of Maine, a hemicellulose pre-extraction technology is now being investigated to improve pulp yields, reduce the organic and inorganic load for liquor recovery, and create a feed stream for the generation of new biomaterials. It is important to understand the composition of unextracted wood, extracted wood, and pulping extracts in the design of an economically viable pilot-scale ethanol plant. For analysis of wood pulp composition, the total analytical mass balance closure was 100.6, 100.3, and 81.6% for unextracted chips, extracted chips, and pulping extracts from HPLC-H column analysis. Meanwhile, the total analytical mass balance from the HPLC-P column was 97.8, 86.3, and 80.7%, respectively. This slight variability between H- and P-column results for analytical mass balance may be within the experimental error of the measurement. The data generated by this analysis are important to further design work in commercializing this process.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2011.10a
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• pp.20-20
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• 2011

In this study, we analyzed 80%MeOH extract of fruits of sorbaria sorbifolia var. stellipila MAX. to measure the total antioxidant capacity by oxygen radical absorbance capacity (ORAC) assay, individual flavonoid content by high-performance liquid chromatography (HPLC). n-Hexane ($1.02{\pm}0.036$), $CH_2Cl_2$ ($0.95{\pm}0.025$), EtOAc ($1.94{\pm}0.065$), n-BuOH ($1.98{\pm}0.054$), D.W. ($1.2{\pm}0.032$) fractions were examined antioxidative activity by ORAC assay. It was revealed that EtOAc($1.94{\pm}0.065$), n-BuOH($1.98{\pm}0.054$) fractions had significant antioxidative activity. The isolation and separation were facilitated using open column chromatography, while separation, purification and identification were accomplished by using high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR).