• Food Science and Preservation
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• v.21 no.4
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• pp.520-528
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• 2014

The purpose of this study was to evaluated a phthalate, heavy metal contents and physicochemical quality properties in korean mudflat solar salt and foreign salts. DEHP in mudflat solar salt (MSS) was detected a low level (9.00~669.89 ppb), but it was shown a high level excess to 1.5 ppm criteria in the foreign solar salt (FSS) 5 type (3,440.64, 3,266.56, 2,189.65, 4,010.69, 4,554.20 ppb) and foreign large solar salt (FLSS) 1 type (1,983.27 ppb). Also, DEHP in FSS 2 type (930.15, 1,310.07 ppb) and FLSS 1 type (924.92 ppb) was detected a high level not excess to criteria. No detected DMP, DEP, DIBP, DBP, DAP, BBP, DCHP and DEHA contents in MSS and foreign salt (FS). Na ion was shown a significantly higher level (p<0.05) in FS (407,345.87~426,612.14 ppm) than in MSS (363,633.98 ppm), but it was shown a high level in Mg (p<0.01), K (p<0.05), Ca ion (p<0.05) of FSS compared to foreign refined salt (FRS). Cl ion (532,727.07 ppm) of MSS was the most low level (p<0.001) compared to FS, but it was shown a high level (p<0.001) in Br ion (625.07 ppm). $SO_4$ ion was not shown a significant difference in DS and FS. It was display a high level in Mn of MSS, and Al, Fe of FLSS. Heavy metal contents (As, Cd, Pb and Hg) in MSS and FS was not significant difference, it was safety level as edible salt.

• Analytical Science and Technology
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• v.11 no.4
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• pp.311-315
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• 1998

Ultra trace metal impurities of high-purity sulfuric acid for semiconductor process have been determined in the concentration of lower than ppb (ng/g) level using high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS).The acid samples were evaporated and concentrated by the factor of 20. No clement in the acids exceeded 1ppb level and most of the clements were determined below 10ppt (pg/g). Elements without spectral interference in mass spectrum, such as In, V, Mn, etc, were determined in the concentration of below 1 ppt level The recoveries in the range of 72% to 127.2% for 0.5 ppb spiked sample were obtained.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.1
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• pp.37-44
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• 2008

In this study, we tried to establish analysis methods of perchlorate with ion chromatography(IC) and liquid chromatography/mass spectrometry(LC/MS) and monitored perchlorate levels in various kinds of water and soil samples. The obtained method detection limit(MDL) of IC was 1 ppb and that of LC/MS was 0.005 ppb in water sample. We monitored the ground and spring water in Busan and the average perchlorate level in ground water was 0.031 $\pm$ 0.011 ppb and that of spring water was 0.013 $\pm$ 0.014 ppb. Wastewater samples were also examined and the levels of perchlorate ranged from 0.007 to 0.380 ppb. The perchlorate levels in all water samples investigated in this study were below the EPA guideline.

• Environmental Engineering Research
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• v.12 no.2
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• pp.46-54
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• 2007

Concentrations of the principal volatile organic compounds, such as benzene, toluene, ethylbenzene, m,p,o-xylene, styrene, and chlorobenzene were measured at the solid waste treatment plants classified into four categories; municipal waste incinerator, municipal waste landfill site, industrial waste incinerator and industrial waste landfill site. The average concentration of VOCs in industrial waste treatment facilities was 33.43 ppb and was significantly higher than that measured at municipal waste treatment facilities (4.71 ppb). The average toluene concentrations measured at incinerators (13.05 ppb) were a little higher than those measured at landfill sites (11.54 ppb). The contribution of the waste treatment facilities to the concentration of benzene (0.35 ppb) and o-xylene (0.15 ppb) in the industrial area was relatively small. However, toluene measured in the industrial waste treatment facilities was the most abundant VOCs with the average concentration of 21.37 ppb. As a result of analyses of fingerprint, in cases of IISH and ILUS, a variety of compounds other than major VOCs were detected in high level. On the Pearson correlation analysis, the correlation was generally positive and some pairs of these VOCs were very strongly correlated (correlation coefficient > 0.75).

• Journal of Environmental Health Sciences
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• v.35 no.1
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• pp.11-20
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• 2009

This study was conducted in industrial area. The level of nitrogen dioxide was measured indoor, outdoor, work and personal in an study area within 5 km from source of pollution and control area 15 km farther from August, 2006 to September. The followings are the summary of this research. The concentration of the indoor and the outdoor $NO_2$ levels in the industrial area are 18.41$\pm$6.35 ppb, 18.51$\pm$3.26 ppb each, and the indoor/outdoor concentration rate is 0.99. The concentration of $NO_2$ in the workplace is 18.59$\pm$10.16 ppb, and the individual exposure rate is 18.80$\pm$5.71 ppb. The concentration of the indoor and the outdoor $NO_2$ levels control area are 12.57$\pm$3.82 ppb, 9.68$\pm$2.16 ppb each, and the indoor/outdoor concentration rate is 1.33. The personal exposure rate is 14.49$\pm$10.06 ppb. The residents of the each area and those of the comparative area spend 80.9% and 76.9% each their time in the indoor. It shows they spend most of their time in indoor. The predictions of the individual exposure rates in the industrial area and the comparative area are 15.10$\pm$6.14 ppb and 10.52$\pm$3.82 ppb each, The concentration levels measured by passive sampler are 18.80$\pm$5.71 ppb and 14.49$\pm$10.34 ppb each. The result of the research is the analysis of the personal exposure rate in indoor, outdoor and workplace of industrial area. This research may bo used as a basic data to manage and to establish the plan for $NO_2$ gas of the industrial area.

• Journal of the Korean Chemical Society
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• v.37 no.11
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• pp.943-950
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• 1993

The determination of trace level germanium in 5.0 ${\times}\;10^{-2}$ M perchloric acid supporting electrolyte solution containing 8.0 ${\times}\;10^{-2}$ M catechol has been investigated by the square wave anodic stripping voltammetry. The optimum conditions in determination of germanium were as follows: deposition time; 120 sec, deposition potential; -0.9 volts vs. Ag/AgCl and frequency; 100 Hz. The determination of germanium was possible regardless of coexistent ion such as copper, lead and silicon. Calibration curve was shown a good linearlity in the range of 0.40 ppb to 2.0 ppm and the detection limit was 0.080 ppb. This method was useful for trace level germanium due to the short analysis time and higher sensitivity.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.2
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• pp.55-71
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• 1989

This study was carried out to determine the ozone concentration to behaviour and the factors to be influenced the variation of its concentration in the ambient air in Seoul. Measurements of ozone concentrations were made at 10 monitoring station to take care of SIHE (Seoul Institute of Health & Environment) during December 1987 to November 1988, also measured the hourly average concentration of sulfur dioxide, total suspended particulate, nitrogen oxide $(NO & NO_2)$, carbon monoxide, hydro carbon $(n-CH_4 & THC)$ and meteorological factors, that is, temperature, humidity, wind velocity wind direction and ultraviolet intensity etc, for the same period at same place. The basis of the data obtained were analyzed statistically along with the various data. The results were as follows; 1. The annually arithmetic mean concentration of ozone for the 10 sites during one years was 10.0 ppb and ranged from 3.1 $\pm$ 4.5ppb at the Kuro industrial complex to 17.2 $\pm$ 18.7 ppb at the Ssangmun site. 2. The frequency of hours on which oxidant concentrations exceeded the present short term standard of ozone (100 ppb) were 78 times. 3. The diurnal patterns of hourly ozone concentrations in Seoul area was a typical bi-modal variation which have 4 to 5 a.m. peak and 3. to 4 p.m peak. 4. The time ozone of highest ozone concentration in a whole day and hight was 1 to 5 p.m and 90.9 percent of appearence rate. 5. The diurnal patterns of hourly ozone concentrations in Seoul were on the whole the order of daytime from 5.8ppb to 28.7 ppb evening from 1.7 to 18.7 ppb night time from 1.9 to 9.3 ppb daybreak from 1.4ppb according to measuring sites, and the highest that observed at the Ssangmun area while the lowest was the Kuro industrial complex monitor sites. 6. The weekly variation of ozone concentration was the higher level ozone concentration in the day of the week occured sunday-monday and weekend but the decrease were observed from wednesday to thursday.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.1
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• pp.85-93
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• 1995

Measurements of ground level ozone concentrations were made in a rural area of Chongwon (Choongbook Province) from June 1993 to July 1994. High values frequently exceeding 100 ppb (ambient air qualyty standard of Korea) were recorded. High ozone concentrations in the boundary layer were primarily correlated with the several meteorological parameters in warm seasons: pressure, radiation, temperature, precipitation and wind velocity. The annual average concentration of ozone at Chongwon was 17ppb, and this value was relatively higher than those for other cities in Korea. O$\_$3/ concentrations were observed to increase when the ridge of a surface anticyclone was passing over the region, and maximum values(.geq.100 ppb) were observed on the rear sides of high pressure centers and in the warm sectors of cyclones(well head of cold fronts). The ozone concentrations had a negative correlation with the concentration of primary pollutants(e.g., total hydrocarbons).

• Analytical Science and Technology
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• v.12 no.4
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• pp.332-340
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• 1999

Homemade cryogenic preconcentration system is constructed to preconcentrate the VOCs in the ambient air collected in canister. Homemade preconcentrator equipped with GC-MS was used for analysis of air sample containing VOCs at ppb level identified in EPA TO-14 method. The system was evaluated for analytical performance by comparison with the results of adsorption tube method widely used in the past, and shows good agreement for concentrations of benzene, toluene, ethylbenzene, and xylenes.

• Korean Journal of Environmental Biology
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• v.32 no.3
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• pp.234-242
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• 2014

In this study, gametotoxicity and embryotoxicity experiments using Hemicentrotus pulcherrimus were carried out to investigate the ecotoxicological effects of bisphenol A (BPA). We examined the effects of BPA on fertilization and normal embryogenesis at various concentrations (0, 300, 500, 800, 1000, and 1500 ppb). The results demonstrated that the fertilization rates were not changed. The normal embryogenesis rates were gradually decreased in a dose-dependent manner, and were significantly lowered following 800 ppb BPA treatment ($EC_{50}$=1056.1 ppb, 95% Cl=981.8~1163.9 ppb). The observed effective concentration and the lowest observed effective concentration of the normal embryogenesis rate were 500 ppb and 800 ppb, respectively. The embryos showed retarded development at each tested concentration, indicating the fact the embryonic development was delayed due to the increasing concentrations of BPA. Furthermore, we examined the expression of glutathione S-transferase (GST) mRNA at various concentrations of BPA in H. pulcherrimus. Interestingly, it was found that the expression level of GST mRNA was significantly increased in the experimental group exposed to BPA. Based on these results, we suggested that BPA at greater than 800 ppb has a toxic effect during the early embryonic stages of H. pulcherrimus, and GST mRNA may be used as a biomarker for risk assessment of BPA contamination.