• Journal of Korean Society for Atmospheric Environment
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• v.21 no.5
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• pp.481-494
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• 2005

The monitoring of persistent organic pollutants (POPs) in the atmosphere is a basis for the study of the fate of POPs in multimedia environments. Recently, passive air samplers (PASs) for POPs have been developed. In this paper, we deal with the principle, properties, and applications of the PAS. The principle of PAS, which has no pump, is physical sorption of semi-volatile organic chemicals on various sorbent materials. The PAS is much smaller than a high-volume air sampler and does not need electricity. These properties of the PAS make it possible to conduct various-scaled environmental monitoring all over the world including the Arctic and Antarctic, but the major disadvantage of PAS is its long sampling periods up to 2 years. To date, four kinds of PAS have been developed: polyurethane foam (PUF), polymer-coated glass (POG), semi-permeable membrane devices (SPMDs), and XAD resin-based PAS. Among them, SPMDs have been commercialized and are most widely used now. Meanwhile, the POPs emitted from China have a large potential to influence the levels and fates of POPs in Korea. Since characteristics of PAS are quite useful to monitor long-range transport of POPs, the use of PAS is highly recommended.

• Journal of Environmental Health Sciences
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• v.31 no.3
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• pp.221-226
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• 2005

Isoflavone was extracted with various concentration of aqueous methanol using whole hypocotyls as the starting material. Whole hypocotyls were preferred as the raw material because the residue could be easily removed from the solvent after the extraction process. Extraction yield was almost constant at the methanol concentration of $20-80\%$. Most of the isoflavone was extracted within 1 hr, and the extraction yield remained almost constant thereafter. When the concentration of methanol was $80\%$, the content of total solid was reduced due to the reduced extraction of contaminating protein as the result of protein insolubilization. Among resins tested, Diaion HP-20, Amberlite XAD-16, and Amberlite IRC-50 showed the highest capacity to absorb the compound. Open column chromatography with Diaion HP-20 showed that $80\%$ aqueous ethanol was most efficient as the eluting solvent with final recovery of the phytochemical being more than $95\%$. Maximum adsorption of the phytochemical occurred at the acidic pH 2-4. When the spatial velocity was increased to 15 and more, the degree of adsorption was decreased, whereas below spatial velocity of 15, the adsorption capacity of isoflavone to the resin was almost constant. The purity of the isoflavone purified by column chromatography was $78\%$.

• YAKHAK HOEJI
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• v.43 no.2
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• pp.143-149
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• 1999

The phytochemical studies of the leaves of Caragana chamlagu were carried out as a sieries of the investigation of medicinal resources. The roots of Caragana chamlagu have been used as neuralgia, arthritis and migraine in the folk medicines of Korea. The methanolic extract of the leaves of Caragana chamlagu was suspended with water and then separated with chloroform. Compound I was isolated from precipitates of these water fraction by recrystalization. The aqueous fraction of MeOH extract was performed to column chromatography on Amberlite XAD-4 and Sephadex LH-20, and three compounds, compound II, compound III, and compound IV were isolated. The structures of the four compounds were elucidated by spectroscopic data of $^1H-NMR$, ^{13}C-NMR$, IR, and FAB-MS. Compound I-IV were tilianine ($acacetin-7-O-{\beta}-D-glycopyranoside$), rutin($quercetin-3-O-{\alpha}-L-rhamnopyranosy(1{\rightarrow}6)-{\beta}-D-glu-copyranoside$), $kaempferol-3-O-{\alpha}-L-rhamnopyranosyl(1{\rightarrow}6)-{\beta}-D-galactopyranoside$, and apigetrin, ($apigenin-7-O-{\beta}-D-glycopyranoside$), respectively.

• YAKHAK HOEJI
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• v.40 no.4
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• pp.394-399
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• 1996

As a series of the studies on the specific and indigenous plants of Mt. Halla, the constituents from stem of Rhamnus taquetii (Rhamnaceae) were investigated. From the water fraction of the MeOH extract, a new flavonol glycoside, kaempferide-3-O-${\alpha}$-L-rhamnopyranosyl(1->3)-${\alpha}$-L-rhamnopyranosyl(1-6)-${\beta}$-D-galactopyranoside, was isolated with three known compounds, quercetin, quercetin-3-methylether, kaempferol, by column chromatographic separation using Amberlite XAD-2, ODS-gel and Sephadex LH-20 and elucidated physico-chemical evidences($^1H-NMR,\;^{13}C-NMR$,IR, EI-Mass, FAB-Mass, and G.C.),respectively.

• Archives of Pharmacal Research
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• v.16 no.3
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• pp.213-218
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• 1993

($\pm$)-Higenamine is known as a cardiotonic principle of aconite root (root of Aconitum spp., Ranunculaceae). A simple and sensitive detection method for higenamine was developed by using gas chromatography-mass spectrometry (GC/MS). The recovery of higenamine after extraction and concentration with XAD-2 resin column was around 95% from rat biological fluids such as bile, plasma and urine. The limits of detection of higenamine in these biological fluids were approximately 0.1 ng/ml each. It has well been suggested that tetrahydroisoquinolines possessing catechol moiety such as higenamine should be subjected to the catechol-O-methyl transferase (COMT) activity in vivo. We detected two major peaks of presumed metabolites of higenamine in the total ion chromatogram obtained from the rat urine sample after the oral adminstration of ($\pm$)-higenamine. The scan mass spectrum of one of the metabolties coincided with those obtained from coclaurine $(C_6$-O-methyl higenamine) and those of the other metabolite are suggestive of isococlaurine $(C_7$-O-methyl higenamine).

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.697-705
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• 2003

The alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) followed by two work-up methods for comparison: isobutoxycarbonyl (isoBOC) derivatization and tert-butyldimethylsilyl (TBDMS) derivatization. Eleven endocrine disrupting chemicals (EDCs) of phenols in biological samples were extracted with acetonitrile and then the acetonitrile layer underwent freezing filtration 6$0^{\circ}C$ for 2 hours. Solid-phase extraction (SPE) was used with XAD-4 and subsequent conversion to isoBOC or TBDMS derivatives for sensitivity analysis with the GC/MS-SIM mode. For isoBOC derivatization and TBDMS derivatization the recoveries were 92.3∼150.6% and 93.8∼108.3%, the method detection limits (MDLs) of bisphenol A for SIM were 0.062 $\mu$ g/kg and 0.010 $\mu$ g/kg, and the SIM responses were linear with the correlation coefficient varying by 0.9755∼0.9981 and 0.9908∼0.9996, respectively. When these methods were applied to mackerel samples, the concentrations of the 11 phenol EDCs were below the MDL.

• 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 Environmental Agriculture
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• v.30 no.2
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• pp.160-165
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• 2011

BACKGROUND: This study carried out to fate of pesticide and investigate worker exposure of pesticide in air after applying granular type pesticide formulation on soil in greenhouse for preventing farmer's pesticide intoxication. METHODS AND RESULTS: The recovery of pesticide, cadusafos, ethoprophos and probenazole on absorbent in air were ranged 80.9~121.1% in charcoal and 90.6~99.0% in XAD-4, respectively. Emission rate of in lysimeter was higher 3~5 times than that of pesticides from topsoil not added water at $35^{\circ}C$ plot after applying a mixture of granular formulation and soil. The ethoprophos concentration in air, 50 cm high from soil surface at greenhouse, was reached the highest 186.4 ${\mu}g/m^3$ within 13 hours and were ranged 17.8~186.4 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 150 g a.i./245 $m^2$. The cadusafos concentration in air at greenhouse was reached the highest 37.3 ${\mu}g/m^3$ within 39 hours and were ranged 10.0~37.3 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 180 g a.i./245 $m^2$. The probenazole concentration in air at greenhouse was reached the highest 1.45 ${\mu}g/m^3$ within 37 hours and were ranged 0.23~1.45 ${\mu}g/m^3$ during 46 hours after applying granular formulation at dose rate 144 g a.i./245 $m^2$. CONCLUSION(s): The result of the reentry interval study demonstrated that reentry intervals for ethoprophos and cadusafos are longer than 48 hours.

• The Plant Pathology Journal
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• v.15 no.3
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• pp.152-157
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• 1999

An antibiotic compound was isolated from the culture of an antagonist against Fusarium oxysporum f. sp. sesami, Bacillus polymyxa strain KB-8, and tested for the control of Fusarium wilt of sesame in greenhouse conditions. Optimum conditions for culturing the antagonist to obtain the maximum antibiotic activity were determined using different culture media, initial medium acidity, and incubation periods for which yeast -malt extract agar with the initial acidity of pH 5 and over 13 days culture were best. Antibiotic substances extracted by methanol had 2 main fractions, KB-8A and KB-8B, in thin layer chromatography (OLC) with Rf values of 0.35 and 0.67 in a solvent system of chloroform : methanol = 7 : 3. The fraction KB-8A wa purified further by XAD-2, silica gel and Sephadex LH-20 column chromatography, and crystalization. Its minimum inhibitory concentrations (MICs) were $12.8\mu\textrm{g}$/ml for F. oxysporum and Alternaria mali, $6.4\mu\textrm{g}$/ml for Colletotrichum gloeosporioides and Rhizoctonia solani, and $3.2\mu\textrm{g}$/ml for Phytophthora capsici. Soil drenching of antibiotic KB-8A in the concentrations of $13.0\mu\textrm{g}$/ml and $26.0\mu\textrm{g}$/ml effectively inhibited the Fusarium wilt of sesame in a greenhouse test, which appeared to be comparable to the fungicide benlate of $6.5\mu\textrm{g}$ a. i./ml.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.2
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• pp.117-132
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• 1998

The main purposes of this study are to investigate the distributional characteristics of polycyclic aromatic hydrocarbons (PAH) in the vapor and particulate phases in the ambient atmosphere, and to evaluate the effect of ambient temperature on the vapor-particle partitioning during the sampling period. A total of 64 samples were collected during a period of 1995 to 1996, using a medium-volume sampler with XAD-2 adsorbents and quartz fiber filters. Analyses of PAH were carried out using HPLC with UV and Fluorescence detections. In this study, a significant seasonal variation in the distributions was observed, reflecting the effect of ambient temperature on the vapor-particle partitioning of PAH. The relationship between the vapor-particle distributions of the 3 to 5 rings PAH and ambient temperature is considered to be well described using the Langmuir adsorption concept. The estimated empirical constants for each PAH in the relationship, particularly for the more volatile compounds, were also comparable with results from other studies. However, it is still difficult to accurately estimate the initial vapor-particle distribution of PAH in the ambient air, since it is not known to what extent the trapped vapours originated from the particles laden in the filter by being volatilized or from the air samples initially present in the vapour phase. The distribution factors for volatile PAH with 3 to 4 rings appeared to be comparable with those in the literature. It should be noted, however, that these distribution factors give information only about the distribution of PAH between the two phases under a specific sampling condition, and hence may provide only semi -quantitative information on the vapor-particle distributions in the atmosphere.