• The Plant Pathology Journal
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• v.40 no.4
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• pp.408-413
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• 2024

The emergence of rice black-streaked dwarf virus (RBSDV) poses a significant threat to global cereal crop cultivation, necessitating the urgent development of reliable detection and quantification techniques. This study introduces a reliable approach for the precise and sensitive quantification of the RBSDV in cereal crop samples, employing a reverse transcription digital polymerase chain reaction (RT-dPCR) assay. We assessed the specificity and sensitivity of the RT-dPCR assay proposed for precise RBSDV detection and quantification. Our findings demonstrate that RT-dPCR was specific for detection of RBSDV, with no cross-reactivity observed with other viruses infecting cereal crops. The RT-dPCR sensitivity was over 10 times that of RT-quantitative PCR (RT-qPCR). The detection limit of RT-dPCR was 0.096 copies/㎕. In addition, evaluation of RT-dPCR assay with field samples was conducted on 60 different cereal crop samples revealed that RT-dPCR (45/60) exhibited superior accuracy compared with RT-qPCR (23/60). In this study, we present a specific and accurate RT-dPCR assay for the detection and quantification of RBSDV.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1221-1227
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• 2011

Ethyl pyruvate (EP) is known as a scavenger of reactive oxygen species (ROS) in the body through its role in the donation of diketone groups to metals to form an EP-metal complex. In order to develop a method for the quantification of EP in biological media, a sensitive and specific, high-performance liquid chromatographyelectrospray ionization-mass spectrometry (HPLC-ESI/MS) method is used to determine the EP-alkali metal ion binding species. The analyte was separated on a ZORBOX SB-C8 ($3.5{\mu}m$, $30mm{\times}2.1mm$ I.D.) column and analyzed in selected ion monitoring (SIM) mode with a positive ESI interface using the m/z 255 $[2M + Na]^+$ ion. The method was validated over the concentration range of $0.5-60.0\;{\mu}g$/mL under 1/9 (v/v) of acetonitrile/methanol solvent system with flow rate 0.05 mL/min. The limit of quantification (LOQ) was $0.5{\mu}g$/mL.

• Analytical Science and Technology
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• v.23 no.4
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• pp.395-404
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• 2010

A multi-residual method using gas chromatography coupled with mass spectrometry (GC/MS/ MS) was developed for the analysis of 105 pesticides. This method was tested on lemons, beans and other vegetables. The pretreatment of these pesticides was performed by liquid-liquid partition followed by cleanup with solid phase extraction cartridge (SPE Florisil), after acetonitrile extraction from matrices and sodium chloride (15 g) addition. The recovery ranged from 71.1% to 126.0% except for azinphosmethyl, famoxadone, fenamidone, flufenoxuron and triadimefon in lemons and from 72.5% to 124.5% in bean. In lemon, the limit of detection (LOD) and limit of quantification (LOQ) were 0.001~150 ng/ mL and 0.004~500 ng/mL, respectively.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.165-171
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• 2012

As a preceding study for investigating the influence of sound wave stimulus on Arabidopsis thaliana metabolomics, the polar secondary metabolomes of the plant were determined using high performance liquid chromatography coupled with tandem mass spectrometry. A total of 10 polar secondary metabolomes were characterized and quantified. Among them, 4 metabolomes, p-coumaroylagmatine isomer (7 and 8), p-coumaroylagmatine isomer (9 and 10) were identified in the plant for the first time. The validation was conducted in terms of linearity, recovery, precision, limit of detection (LOD) and limit of quantification (LOQ). The validated method was applied to the simultaneous quantification of the 10 polar secondary metabolomes.

• Analytical Science and Technology
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• v.34 no.4
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• pp.153-159
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• 2021

In this study, we describe the development of a new high-performance liquid chromatography (HPLC) method for the simultaneous analysis of six bioactive compounds (including gallic acid, epicatechin 3-gallate, quercitrin, afzelin, quercetin, and kaempferol) from Orostachys japonicus. The extraction method was investigated and optimization of the extraction time (min), solvent composition (%), and solvent to material ratio were conducted. As a result, 30 min extraction with 50% methanol and 40:1 mL/g of solvent: material ratio achieved the highest extraction efficiency with a yield of 3.32 mg/g. Furthermore, the developed HPLC method was validated and the correlation coefficient (R) values were within the satisfactory range of 0.9995-0.9999 over the linearity range of 1.53-417 ㎍/mL. The limit of detection and limit of quantification for the six active components were between 0.03-0.08 ㎍/mL and 0.08-0.26 ㎍/mL, respectively. With these newly optimized and developed methods, four batches of O. japonicus were analyzed to confirm the high extraction efficiency of the method and the feasibility of an application.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.682-687
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• 2021

The purpose of this study was to validate a high-performance liquid chromatography (HPLC) method for the quantitative analysis of quercetin in various foods. The method was based on HPLC-UV (360 nm). The method was validated using candy, beverage, and sausage which were tested for specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy, and the measurement uncertainty was assessed. Matrix-matched calibration was also applied. The calibration curves (0.5-50 mg/L) showed good linearity (r²≥0.9998). LOD and LOQ ranged from 0.15 to 0.31 mg/kg and from 0.44 to 0.93 mg/kg, respectively. The average accuracy and precision at 0.5, 2.5, and 10 mg/kg ranged from 84.3 to 102.0% and 0.7 to 3.0 relative standard deviation (RSD%), respectively. This study confirmed the applicability of the proposed method by applying it to commercial products, such as teas and beverages. Thus, the proposed analytical method is suitable for quantifying quercetin in various foods.

• 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 Research
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• v.48 no.1
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• pp.9-16
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• 2008

A method for the quantification of eugenol in the medicinal herb Clove was developed and validated. For preparation of sample solutions clove was dried at $60^{\circ}C$ for 2h and ground by mixer and extracted with 95% ethanol for shaking extraction. The elutes were analyzed by HPLC system included a reversed phase column, a isocratic mobile phase of 60% methanol and PDA detector set at 280 nm. Calibration graphs were linear with very good correlation coefficients ($r^2>0.9999$) from $0.0125~1{\mu}g/ml$. The limit of detection per sample injection ($20{\mu}l$) was $0.81ng/{\mu}l$ and limit of quantification was $2.47ng/{\mu}l$. The method showed good intra-day precision (%RSD 0.08 ~ 0.27%) and inter-day precision (%RSD 0.32 ~ 1.19%).

• Journal of fish pathology
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• v.34 no.2
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• pp.261-269
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• 2021

This study presents the evaluation of sample extraction and purification procedure for the determination of residues of febantel and its metabolites, fenbendazole, oxfendazole and oxfendazole sulfone in rockfish (Sebastes schlegeli) muscle using liquid chromatography-tandem mass spectrometry. Residues of febantel and its metabolites in rockfish muscle were analyzed using each different sample preparation method from Korean Food Standards Codex (KFSC), Food Safety and Inspection Service (FSIS, USA), and the modified FSIS method using QuEChERS kit (FSIS-Q), respectively. Each method was compared for mean recoveries and repeatabilities. Since FSIS-Q showed higher repeatabilities (coefficient of variation, CV of 2.4%~10.9%) than those of FSIS method (CV of 4.6%~17.5%), recoveries from FSIS-Q were compared with those from KFSC method. FSIS-Q showed significantly higher recoveries of 83.1%~110.1% (P < 0.05) than those from KFSC method of 64.7%~107.4%. In addition, FSIS-Q showed a good linearity over the range of 2.5~200 ㎍/kg, and excellent sensitivities with limit of detection of 0.46~0.71 ㎍/kg and limit of quantification of 1.08~2.15 ㎍/kg. Although all the sample preparation methods turned out to be able to meet CODEX guideline for all the compounds, FSIS method and FSIS-Q validated in this study could be applied to screening and quantification for residues of febantel and its metabolites in rockfish muscle with efficient preparation procedures.

• Korean Journal of Veterinary Service
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• v.45 no.3
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• pp.243-248
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• 2022

The HPLC conditions for analysis of ivermectin in solutions dosage forms of commercial anthelmintics are different for each product. The purpose of this study was to establish a standardized chromatographic method for the quantification of ivermectin in solution. The separation was achieved on Waters Xbridge C18 column (4.6×150 nm, 5 ㎛) using different kinds of mobile phase composed of water/methanol/acetonitrile (15/34/51, v/v and 19.5/27.5/53, v/v), with UV detection at wavelengths 245 nm and 254 nm. A total of five commercial ivermectin in solution samples were analyzed. In this study, the optimal chromatographic conditions for analysis of ivermectin in solution were mobile phase of water/methanol/acetonitrile (15/34/51, v/v) at a flow rate of 1.0 mL/min and a detection wavelength of 245 nm using a Waters Xbridge C18 column (4.6×250 nm, 5 ㎛) at a column temperature of 25℃. The linearity was observed in the concentration range of 50~150 ㎍/mL, with a correlation coefficient, r²= 0.99999. The limit of detection and the limit of quantification were 0.88 and 2.68 ㎍/mL, respectively. The accuracy (% recovery) was found to be 98.9 to 100.3%. Intra-day and Intermediate precisions with relative standard deviations were less than 1.0%. The content of ivermectin for five market samples ranged 91.2~102.7%. The proposed method was also found to be robust, therefore, the method can be used for the routine analysis of ivermectin in solutions dosage forms.