• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.87-94
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• 2007

Pyrethroid insecticide have widely been used for agricultural sector and residential environments. To assess the exposure of insecticide which is absorbed through skin the analysis of urinary metabolite is essential. At present, the urinary 3-PBA was analyzed using liquid-phase extraction. But LPE have many limitations, such as long pre-treatment time and low recovery. So, this study was conducted to determine the optimum conditions for analysing 3-PBA in urine using solid phase extraction. Furthermore, this study intend to investigate the relation of concentrations of pyrethroid, deltamethrin in air and 3-PBA in urine. The optimum condition for hydrolysis was found to be done with hydrochloric acid for one hour. The recovery rates of 3-PBA were $84.6%{\pm}1.2%$, $54.8{\pm}0.9%$, $99.8{\pm}1.2%$ with XAD-2, XAD-7, XAD-16 using as the aborbents and acetone as eluents respectively. But acetonitrle and methanol gave low recovery rate and methyl cellosolve could not elute the compound. The amount of acetone for elution were 6mL, 9mL, 3mL for XAD-2, XAD-7, XAD-16 as absorbents respectively. The non-absorbed rates was $0.8{\pm}0.5%$, and $0.7{\pm}0.3%$ under XAD-16, mesh size 140-200, amount of resin 1.4g and the flow rate of eluent was 0.1mL/min. In the concentration process, we obtained 11 times higher concentration of material. The amounts of urinary 3-PBA were. The LODs of 3-PBA and deltamethrin were 0.004 mg/L, 0.038 mg/L, respectively. The further research of minute monitoring which include spray pattern, environmental condition is needed And more research about the relation between total pyrethroid exposure and urinary various metabolite are also necessary.

• Journal of agricultural medicine and community health
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• v.36 no.4
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• pp.218-226
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• 2011

Objectives: Paraquat (PQ) is a widely used ionic pesticide that is fatal when ingested accidentally or for suicidal purposes. It is thought that chronic exposure of PQ is related with the development of Parkinson's disease, but epidemiological studies have not yet confirmed that theory. This study attempted to estimate the possibility of environmental PQ exposure through soil and water. Materials and Methods: We analyzed the amount of decomposed PQ solution in wet soil after exposure to ultraviolet light. An artificial rainfall condition was simulated over soil sprayed with PQ to measure the amount of eluted PQ. In addition, PQ was diluted in water from three differently rated rivers and the changes in PQ concentration were measured after ultraviolet exposure over one month. High performance liquid chromatography/ultra violet detection was used to analyze the concentrations of PQ. Results: In the method we used, the recovery rate of PQ showed a precision rate less than 5%, an accuracy greater than 88%, and the calibration equation was y=5538.8x-440.01($R^2$=0.9985). There were no significant differences in the concentrations of PQ obtained from the three specimens over a 1-week period. From the PQ-sprayed soil, the artificial rainfall conditions showed no PQ elution over a 1-month period, and there was no significant differences in PQ concentrations according to ultraviolet exposure among the three samples. Conclusions: PQ remains well adsorbed naturally in soil. However, it may still exist in an integrated state for a long time in the hydrosphere, so the possibility of PQ exposure through drinking water cannot be disqualified.

• KSBB Journal
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• v.21 no.3
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• pp.224-229
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• 2006

FEMLAB is a powerful interactive environment for modeling, solving all kinds of scientific and engineering problems based on partial differential equations(PDEs). Separation process of chiral compound in HPLC columns was simulated by FEMLAB. To study change of elution profile with isotherm models, non-competitive and competitive Langmuir adsorption isotherm were adopted. Separated material was (R, S)-ibuprofen [(R, S)-2-(4-isobutyl phenyl) propionic acid], an anti-inflammatory agent, which retain the pharmacological activity in the (S)-(+)-enantiomer. Sample concentrations were changed from 0.5 mg/ml to 2.0 mg/ml at a flow rate of 1 ml/min and flow rate varied from 1 ml/min to 3 ml/min at an ibuprofen concentration of 2.0 mg/ml and $20{\mu}l$ of injection volume. Simulated results were well fitted with experimental data.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.1
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• pp.57-63
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• 2021

In this study, isoscoparin was selected as an indicator component to develop Silene seoulensis extract as a functional cosmetic material, and we developed an analysis method using high performance liquid chromatography (HPLC) for quality control. HPLC was performed on a Unison US-C18 with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methanol at a flow rate of 1.0 mL/min at 35 ℃, and the detection wavelength was 330 nm. The HPLC method was performed in accordance with the international conference on harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.02 and 0.07 mg/mL respectively. Calibration curves showed good linearity (R2 > 0.99988), and the precision of analysis was satisfied (less than 0.46%). In addition, the recovery rate was in the range of 99.10 to 101.61%, it was shown to be accurate. This result indicated that the established HPLC method is very useful for the determination of marker compounds in Silene seoulensis extracts.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.26-32
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• 2001

Influence of various rates of fractionated raw cow manure on hydraulic conductivity of the soil was observed. The fractionated raw cow manure(hereafter as FRCM) incorporated into soil. The hydraulic conductivity was measured for the double-layered soil while maintaining the water head by 5 cm over the soil surface. The influence on the mobility of $NO_3{^-}$-N transformed from the FRCM was analyzed. The upper layers (Wolgok series) were made with FRCM ranging from 0% to 10.4 % on weight basis for air-dried soil while the organic matter in the bottom layers (Chungwon series) was removed by combustion. The initial bulk densities for both layers were adjusted to $1.25g\;cm^{-3}$. In this experiment the $K_{sat}$ for the upper layer gradually decreased from $4.71{\times}10^{-3}cm\;min^{-1}$ to $1.2{\times}10^{-3}cm\;min^{-1}$ with increasing the rate of the FRCM from 0 % to 10.4%, while the Ksat of the bottom layer was maintained as $3.7cm\;min^{-1}$. For the double-layered soil columns, the $K_{sat}$ decreased with increasing rate of FRCM at the upper layer from $1.7{\times}10^{-3}cm\;min^{-1}$ to $8{\times}10^{-4}cm\;min^{-1}$ as the rate of organic matter increased from 0 % to 10.4 %, while it took almost 7 days to 64 days to obtain the steady state $K_{sat}$ The elution patterns of $NO_3{^-}$-N and $NH_4{^+}$-N showed that the amounts of both $NO_3{^-}$-N and $NH_4{^+}$-N rapidly approached to the maximum ranging from $14.8mmol_c\;kg^{-1}$ to $0.58mmol_c\;kg^{-1}$ as the rate of FRCM decreased from 10.7 % to 0 % which is equivalent to indigenous amount of $NO_3{^-}$-N and $NH_4{^+}$-N. And the amounts of $NO_3{^-}$-N were approximately three or four time than those of $NH_4{^+}$-N, indicating that the transformation rate of $NO_3{^-}$-N was improved by the higher FRCM rate. Thus, the ability of a soil to supply N can be predicted from its mineralization parameters and leaching potentials influenced by water flow regime in soil.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.397-407
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• 2017

This research aims to analyze and compare the drought resistance of 7 species of landscape trees commonly grown in Korea. The 7 species are: Camellia japonica, Rhaphiolepis indica, Quercus glauca, Machilus thunbergii, Daphniphyllum macropodum, Dendropanax morbifera and Cinnamomum camphora. In order to analyze their drought resistance, the samples were left without irrigation for 30 days (05/09/2016 ~ 05/10/2016), during which period their respective drought resistor, relative water content, electrolyte elution figures and proline content were measured. As the non-irrigation proceeded, C. camphora was the first to wither, followed by D. morbifera, then D. macropodum, then M. thunbergii, then Q. glauca, then R. indica then finally C. japonica. Of the 7 species, Q. glauca, C. japonica and R. indica can be considered highly drought resistant, since they survived for longer than 3 weeks without irrigation. Relative water content (RWC) plummeted dramatically after the first 15 days of non-irrigation. Whereas RWC readings of C. camphora, D. morbifera, D. macropodum and M. tunbergii dropped by 40% or more, the other 4 species reported a relatively low rate of decrease at 20% or lower. The Camellia japonica, the R. indica and Q. glauca, which were the species with relatively high drought resistance, showed low proline content and electrolyte elution figures, whereas those of C. camphora, D. macropodum, D. morbifera and M. tunbergii were higher. Analysis through the nonlinear regression analysis logistic model showed that non-irrigation proved fatal for the 7 sample species in a range of 22.7 to 37.6 days. The C. japonica, R. indica, Q. glauca and M. tunbergii demonstrated a high drought resistance of 30 days or longer, whereas C. camphora, D. morbifera and D. macropodum had a low resistance of 25 days or less to drought from lack of water. In conclusion, out of the 7 species of broad-leaved evergreen trees tested, C. japonica, R. indica and Q. glauca seem to be suitable for use as landscape trees, owing to their high drought resistance.

• Analytical Science and Technology
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• v.9 no.4
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• pp.364-372
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• 1996

The sorption and desorption properties of U(VI), Th(IV), Zr(IV), Cu(II), Pb(II), Ni(II), Zn(II), Cd(II) and Mn(II) ions on XAD-16-[2-(2-thiazolylazo)-p-cresol](TAC) chelating resin were studied by elution method for selective separation, concentration and recovery of trace metal ions in sea water. The optimum conditions for the sorption of metal ions were examined with respect to flow rate, pH and concentration of buffer solution. The overall capacities of some metal ions on this chelating resin were 0.41mmol U(VI)/g resin, 0.55mmol Th(IV)/g resin, 0.43mmol Cu(II)/g resin, and 0.32mmol Zr(IV)/g resin, respectively. The elution order of metal ions obtained from breakthrough capacity and overall capacity at pH 5.0 was found as Th(IV)>Cu(II)>U(VI)>Zr(IV)>Pb(II)>Ni(II)>Zn(II)>Cd(II)>Mn(II). Desorption of characteristics for metal ions were investigated with desorption agents such as $HNO_3$, HCl, $HClO_4$, $H_2SO_4$, and $Na_2CO_3$. It was found that most of metal ions except Zr(IV) showed high desorption efficiency with 2M $HNO_3$. But, desorption and recovery of Zr(IV) ion were successfully performed with 1M $H_2SO_4$. The resin was applied for separation and preconcentration of trace amount of U(VI) ion from artificial sea water and the recovery of U(IV) was over 96%.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.272-285
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• 1987

In order to obtain the data for the effective separation and purification of lysozyme from egg white, optimal conditions for the homogenization of egg white and lysozyme activities of some fresh hen eggs were examined. The recovery and purity of lysozyme isolated by the direct crystallization method, the adsorption with Bentonite and the batch method with Duolite were also investigated. The results obtained were summarized as follows; 1. On the homogenization of egg white, optimal stirring time and stirring rate for the measurement of the lysozyme activities were found to be 10 min. and 2,000 rpm respectively. 2. On the activities of lysozyme in the fresh hen eggs, the activities of W. Leghorn was greater than that of R. Island or Ogol fowl, and the activities of the thick white was a little greater than that of the thin white. 3. The residual lysozyme activities of the hen eggs stored at $4^{\circ}C$ was greater than that of the ones stored at $25^{\circ}C$ or $-20^{\circ}C$ over the storage periods. 4. Hen egg lysozyme recrystallized three times by the method of direct crystallization showed the recovery of 64.3% and the increase of 29 fold in specific activities. 5. By the adsorption method with bentonite, lysozyme in the egg white was adsorbed to 95.7%, and the elution rate of the ones adsorbed was 89.1%, and the increase in specific activities was 13 fold. 6. In the experiment exploying duolite as an adsorbent, Jysozyme in the egg white was obtained with the bound rate of 97%, the recovery rate of 84.8%, and was purified by 30fold.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4682-4691
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• 2014

Banhabaekchulchhonma-tang is a traditional Korean herbal prescription with a range of pharmacological activities. In this study, the simultaneous analysis of 12 kinds of marker components, Homogentisic acid, Hesperidin, Naringin, Alisol A, Atractylenolide II, Atractylenolide III, Ginsenoside Rg1, Formononetin, Gastrodin, Berberine, Palmatine and 6-gingerol, in Banhabaekchulchhonma-tang was performed using high-performance liquid chromatography (RP-HPLC). The standard sample of commercial $C_{18}$ reversed phase-column using water (0.1% TFA) and acetonitrile as the mobile phase with a step gradient elution mode. The flow rate (1.0mL/min), injection volume ($10{\mu}L$) and column oven temperature ($40^{\circ}C$) at a 200, 220, 280 and 340nm wavelength was conducted. All calibration curves of the standard components showed good linearity ($r^2$ >0.999). In addition, the limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.012 to $0.878{\mu}g/mL$ and 0.009 to $0.290{\mu}g/mL$. The precision intra-day and inter-day were ranged from 0.07 to 1.21% and 0.20 to 0.90%, respectively. The recoveries ranged from 97.17 to 108.40%. Each sample amount showed a very small change. These results highlight the efficient quality evaluation of Banhabaekchulchhonma-tang.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.553-558
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• 2012

A simple new method was developed for the determination of betaine in Fructus Lycii using hydrophilic interaction liquid chromatography with evaporative light scattering detection (HILIC-ELSD). Good chromatographic separation and reasonable betaine retention was achieved on a Kinetex HILIC column ($2.1{\times}100mm$, $2.6{\mu}m$) packed with fused-core particle. The mobile phase consisted of (A) acetonitrile and (B) 10 mM ammonium formate (pH 3.0)/acetonitrile (90/10, v/v). It was used with gradient elution at a flow rate of 0.7 mL/min. The column temperature was set at $27.5^{\circ}C$ and the injection volume was $10{\mu}L$. The ELSD drift tube temperature was $50^{\circ}C$ and the nebulizing gas (nitrogen) pressure was 3.0 bar. Stachydrine, a zwitterionic compound, was used as an internal standard. Calibration curve over $10-250{\mu}g/mL$ showed good linearity ($R^2$ > 0.9992) and betaine in the 70% methanol extract of Fructus Lycii was well separated from other peaks. Intraand inter-day precision ranged from 1.1 to 3.0% and from 2.4 to 5.3%, respectively, while intra- and inter-day accuracy ranged from 100.0 to 107.0% and from 94.3 to 103.9%, respectively. The limit of quantification (LOQ) was $10{\mu}g/mL$ and the recoveries were in the range of 98.2-102.7%. The developed HILIC-ELSD method was successfully applied to quantitatively determine the amount of betaine in fourteen Fructus Lycii samples from different locations, demonstrating that this method is simple, rapid, and suitable for the quality control of Fructus Lycii.