• Analytical Science and Technology
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• v.10 no.5
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• pp.343-349
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• 1997

Analytical method using the reversed phase ion-pair chromatography (RP-IPC) for the determination of kasugamycin(5-amino-2-methyl-6-(2,3,4,5,6-pentahydroxy cyclohexyloxy)tetrahydropyran-3-yl-amino-${\alpha}$-imino acetic acid), pesticide as fungicide bactercide has been established. The retention behavior of kasugamycin in the RP-IPC was examined with respect to the effect of concentrations of organic modifiers, pH of eluent and types and concentrations of the counter ions as ion-pair reagent. This method developed by the optimum factors, can be used for the application of the quality control in the crude product and its formulation.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.11-20
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• 2015

Objectives : Ongyeong-tang (OGT) is a traditional herbal formula used to cure gynaecological disorders. OGT consists of 12 herbal medicines containing various bioactive components. Therefore, the development of suitable analytical method for the marker compounds is necessary for the quality control of OGT. Methods : Determination of the 18 marker compounds in OGT preparations was quantitatively performed by high-performance liquid chromatography-photodiode array detection analysis. The marker compounds were separated on a reversed-phase C ₁₈ column and the analytical method was successfully validated, which was applied to compare OGT extracts from laboratory preparation and commercial OGT granules. Results : Limit of detection and limit of quantification values were in the ranges of $0.001-0.016{\mu}g/mL$ and $0.003-0.047{\mu}g/mL$, respectively. Precision was 0.03-3.71 % within a day and 0.03-3.81 % over four consecutive days. Recovery of marker compounds ranged from 90.63-108.26 %, with relative standard deviation (RSD) values < 4.0 %. Reproducibility was < 2.5 % of the RSD value. The 18 marker compounds were stable within 16 h at $10^{\circ}C$, with the RSD value < 3.5 %. Quantitative analysis results showed that the quantities of the 18 marker compounds varied among OGT samples. Pearson coefficient evaluation and principal component analysis demonstrated that an OGT water extract produced by a laboratory method clearly differed from commercial OGT granules. Conclusions : The developed analytical method was simple, precise, and reliable. Therefore, it can be used for the quality assessment of OGT preparations.

• Journal of Pharmaceutical Investigation
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• v.41 no.1
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• pp.25-30
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• 2011

Recently, Korean Food and Drug Administration (KFDA) has focused on developing quality control guidelines for all commercial products in Korea to enforce regulations, improve the quality control, and protect consumers by developing prevalently used and efficient analytical tools to determine and quantify target compounds. Because the Korean Pharmacopeia (KP) presents microbiological assays for biotin, which is laborious and time-consuming, this study is focused on applying HPLC-UV to detect and quantify biotin in complex drugs and dietary supplements like multi-vitamin. Biotin in complex drugs was extracted from methanol and analyzed using mobile phase with 10 mM potassium phosphate (monobasic, pH=3.0) in distilled water and acetonitrile. Gradient condition was used to successfully detect and quantify biotin within 20 minutes. Validation result for linearity was significant that average $r^2$ was 0.999 (n=3) and its relative standard deviation (RSD) was 0.0578% which was less than 2%. Using this method, quantification of biotin in complex drugs was completed successfully and recovery tests were finished that recovery percentage greater than 95% with relative standard deviation less than 2%.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.1
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• pp.103-116
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• 1994

This study was conducted to evaluate accuracy and precision of reference values used for quality control of the Korean industrial hygiene laboratory for three rounds. Factors affecting on accuracy and precision, including analytical procedures, were investigated. The results are summarized as follows. 1. Pooled relative standard deviation of reference values analyzed by reference laboratories was 2.01-5.91%, and that by both reference laboratories and participated laboratories was 3.18-6.63%. Better results were obtained when results of reference laboratories were employed. 2. Significant relationship was indicated between analytical precision and concentration of materials in samples. Variation increased by decreasing sample concentration. 3. Recoveries of lead and cadmium were about 98.6% and 99.8% respectively. There was a significant difference between lead values with and without recovery correction. 4. Organic solvent results corrected by desorption efficiency only and those corrected by Both internal standards and desorption efficiency were more accurate than those uncorrected. But, the latter was the best.

• Nuclear Engineering and Technology
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• v.36 no.5
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• pp.450-459
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• 2004

For the evaluation of emission sources by air sampling, airborne particulate matter for fine (<2.5 ${\mu}m2$ EAD : $PM_{2.5}$) and coarse partical (2.5-10 ${\mu}m2$ EAD : $PM_{2.5-10}$ fractions were collected using a Gent stacked filter unit low volume sampler and two types of polycarbonate filters. Air samples were collected twice monthly at two regions in and around Daejeon city in the Republic of Korea from January to December 2002. Monthly mass concentration of $PM_{2.5}$ and $PM_{2.5-10}$ were measured and the concentrations of 10 marker elements (Al, Sc, Ti ; Na, Cl ; As, V. Sb, Br, Se) were determined by an instrumental neutron activation analysis. Analytical quality control was corried out using certified reference materials. Enrichment factors were also calculated from the monitoring data to classify the anthropogenic and crustal origins.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.231-236
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• 1995

The object of this thesis is an analytical study on flexural deformation of high strength concrete structures using reliability theory. Using the established experimental data that have been presented in various documents the stress-strain relationship curves of high strength(500kgf/$\textrm{cm}^2$)models are proposed. Based on both methods of logarithm regression analysis and multiple regression analysis adopted in order to establish the relationships between design parameters, response random variables and flexural deformation analyzed using Monte Carlo simulation and Simpson composite formula. Additional random variables are introduced to incorporate both the confidence in the analytical accuracy of engineering mechanics associated with structural response quantities and the uncertainty in the construction quality control. The result is expected to accomodate other important design parameter of high strength concrete design in treating reliability theory that practicing engineers, structural engineering often face.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.350-356
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• 2012

Performance of proficiency testing and the validation of analytical method was included a scheme of quality assurance in analytical chemistry laboratory to monitor a laboratory's performance abilities and produce consistently reliable data. This study was assessed the applicability of proficiency testing scheme proposed for analytical laboratories of pesticide product in domestic. The validation of analytical methods, stability and homogeneity for formulated pesticide products (emulsifiable concentrate) of emamectin benzoate and lufenuron was confirmed for the proficiency testing. The z-score of 33 participation laboratories for emamectin benzoate were that the numbers of outlier were 2 laboratories (6.0%), z-score outside the range from -3 to 3 designated "unaccptable" were 2 laboratories and z-score in the ranges -2 to -3 and 2 to 3 designated "questionable" were 3 laboratories (9.0%). Three laboratories (9.0%) showed the z-score designated "questionable" for lufenuron. The additional proficiency testing for various product types will be needed to establish the scheme of quality control.

• Analytical Science and Technology
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• v.33 no.5
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• pp.224-231
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• 2020

With the improvement in the standard of living and extension of life expectancy, the incidence of prostate diseases has increased yearly, thus becoming a serious disease affecting the health of men. The extract mixture of Cornus officinalis and Stauntonia hexaphylla leaves is a developed functional food formula to improve prostate health. This study developed a simultaneous analytical method of bioactive compounds for quantifying the mixture of Cornus officinalis and S. hexaphylla leaves using high-pressure liquid chromatography-ultraviolet (HPLC-UV). HPLC analytical condition was performed on a Hector C₁₈ column with a mobile phase of 0.1 % formic acid in water (A) and 0.1 % formic acid in acetonitrile (B) under the following gradient conditions: 0-50 min, 12 %-40 % (B) at a flow rate of 1.0 mL/min. Meanwhile, this method was validated properly and successfully used to quantify the bioactive components of morroniside and hederacoside D in 20 sample batches and assess the quality of different ages and seasons of S. hexaphylla leaves. The result showed that the content of morroniside in the extract mixture of Cornus officinalis and S. hexaphylla leaves ranged from 1.38-1.62 mg/g, and the hederacoside D ranged from 28.42-32.02 mg/g, suggesting that this novel analytical method will be suitable for the quality control of the extract mixture to improve benign prostatic hyperplasia.

• Analytical Science and Technology
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• v.12 no.4
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• pp.312-317
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• 1999

Quality control was carried out the three analytes, BOD, COD, TN, TP of high and low concentration for thirteen laboratories. Evaluation values of Quality control was determined from average value which were made by six times test, repeatedly and periodically. This value had not only error ratio of within 5% from prepared sample value but also high precision of standard deviation, 0.44 (BOD, low concentration), 2.15 (BOD, high concentration), 0.12 (COD, low concentration), 1.63 (COD, high concentration), 0.35 (TN, low concentration), 1.99 (TN, high concentration), 0.05 (TP, low concentration), 0.14 (TP, high concentration). Upper (Lower) Warning Limit (ULWL) and Upper (Lower) Acceptance Limit (ULAL) values made from quality control chart. Three (5.30, 9.70, 5.30 mg/L) and five laboratories were over ULAL value in low and high BOD concentration, respectively. Two (41.00, 30.60 mg/L) and four laboratories were over ULAL value in low and high COD concentration, respectively. while, other eleven laboratories appeared reliable data. One laboratory (0.70 mg/L) was over ULAL at low TN concentration, while other eleven laboratories had reliable values. In case of high TN concentration, eleven laboratories were over ULAL value, it should be focuced for improvement of reliability about measurement and analysis of TN. Four (1.14, 0.45, 0.64, 1.49mg/L) and seven laboratories were over ULAL in low and high TP concentration, respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1547-1553
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• 2011

An effective analytical method of gas chromatography/mass spectrometry (GC/MS) was developed for the rapid determination of essential oils in the crude extract of Acorus species (Acorus gramineus, Acorus tatarinowii, and Acorus calamus). Major phenypropanoids (${\beta}$,${\alpha}$-asarone isomers, euasarone, and methyleugenol) and ${\beta}$-caryophyllene in Acorus species were used as marker compounds and determined for the quality control of herbal medicines. To extract marker compounds, various extraction techniques such as solvent immersion, mechanical shaking, and sonication were compared, and the greatest efficiency was observed with sonication extraction using petroleum ether. The dynamic range of the GC/MS method depended on the specific analyte; acceptable quantification was obtained between 10 and 2000 ${\mu}g/mL$ for ${\beta}$-asarone, 10 and 500 ${\mu}g/mL$ for ${\alpha}$-asarone, 10 and 200 ${\mu}g/mL$ for methyleugenol, and between 5 and 100 ${\mu}g/mL$ for ${\beta}$-caryophyllene. The method was deemed satisfactory by inter- and intra-day validation and exhibited both high accuracy and precision, with a relative standard deviation < 10%. Overall limits of detection were approximately 0.34-0.83 ${\mu}g/mL$, with a standard deviation (${\sigma}$)-to-calibration slope (s) ratio (${\sigma}$/s) of 3. The limit of quantitation in our experiments was approximately 1.13-3.20 ${\mu}g/mL$ at a ${\sigma}$/s of 10. On the basement of method validation, 20 samples of Acorus species collected from markets in Korea were monitored for the quality control. In addition, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed on the analytical data of 20 different Acorus species samples in order to classify samples that were collected from different regions.