• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.336-343
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• 2000

Purpose: Thallous-201 chloride produced at Korea Cancer Center Hospital(KCCH) is used in detecting cardiovascular disease and cancer. Thallium impurity can cause emesis, catharsis and nausea, so the presence of thallium and other metal impurities should be determined. According to USP and KP, their amounts must be less than 2 ppm in thallium and 5 ppm in total. In this study, the detection method of trace amounts of metal impurities in $[^{201}Tl]$TICI injection with polarography was optimized without environmental contamination. Materials and Methods: For the detection of metal impurities, Osteryoung Square Wave Stripping Voltammetry method was used in Bio-Analytical System (BAS) 50W polarograph. The voltammetry was composed of Dropping Mercury Electrode (DME) as a working electrode, Ag/AgCl as a reference electrode and Pt wire as a counter electrode. Square wave stripping method, which makes use of formation and deformation of amalgam, was adopted to determine the metal impurities, and pH 7 phosphate buffer was used as supporting electrolyte. Results: Tl, Cu and Pb in thallous-201 chloride solution were detected by scanning from 300 mV to -800 mV Calibration curves were made by using $TINO_3,\;CuSO_4\;and\;Pb(NO_3){_2}$ as standard solutions. Tl was confirmed at -450 mV peak potential and Cu at -50 mV Less than 2 ppm of Tl and Cu was detected and Pb was not detected in KCCH-produced thallous-201 chloride injection. Conclusion: Detection limit of thallium and copper is approximately 50 ppb with this method. As a result of this experiment, thallium and other metal impurities in thallous-201 chloride injection, produced at Korea Cancer Center Hospital, are in the regulation of USP and KP Polarograph could be applied for the determination of metal impurities in the quality control of radiopharmaceuticals conveniently without environmental contamination.

• Journal of Soil and Groundwater Environment
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• v.12 no.6
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• pp.107-117
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• 2007

Dispersion characteristics and envirounmental impactes of the stream sediments were investigated and geochemical disaster in the Namhae-Hwagye area was predicted. Stream sediments having no possibility of contamination effect and representing drainage basins were collected. Major and hazardous elements concentrations were determined by XRF, ICP-AES and NAA analysis methods. Acid decomposition for the ICP-AES have been used $HClO_4$ and HF with $200^{\circ}C$ heating at 1'st and after that $HClO_4$, HF and HCl with $200^{\circ}C$ heating at 2'nd stage. Hazardous elements concentrations for the stream sediments in the Namhae area were Cu $5.66{\sim}168\;ppm$, Pb $18.0{\sim}40.7\;ppm$, Cr $21.6{\sim}147\;ppm$, Co $4.86{\sim}25.3\;ppm$. Hazardous elements concentrations for the stream sediments in the Hwagye area were Cu $16.4{\sim}41.2\;ppm$, Pb $26.5{\sim}37.5\;ppm$ Cr $79.6{\sim}153\;ppm$, Co $15.7{\sim}29.5\;ppm$. Concentration of Cu and Co in the stream sediments show a negative correlation with $SiO_2$ in all study area. According to E.I.(Enrichment Index) of stream sediments was not enriched in study area. And average E.I. was 0.35 (Namhae) and 0.56 (Hwagye) respectively. The stream sediments were enriched as in order of Pb > Cr > Co > Cu. And the average of Enrichment Factor (E.F.) was 0.46 to 2.84, respectively. E.F. concentration of Cu and Co were nearly similar enrichment characteristic but E.F. concentration of Cr were higher enrichnent characteristic in Namhae than Hwagye area. Pb was highly enriched in all study area but the tolerable level that used to investigate the enrichment degree of hazardous elements, was not exposed to harmful hazardous elements.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.323-332
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• 2003

This study was carried out to provide information for the present status of soil pollution near abandoned old-zinc mining area through analysis of bound form and 0.1 N-HCl extractable concentrations of heavy metals in soils and plants. Feasibility of endemic plants for phytoremediation was evaluated by the investigation of vegetation in soils. Cd contents of the selected samples near old-zinc mining soils ranged from 0.2 to $42mg\;kg^{-1}$. Nonagricultural soils near the mining area contained great amounts of Zn, Pb, Cd, and Cu than the paddy and upland soils. Some Korean wild plants, Artemisia princeps, Artemisia montana, Erigeron canadensis, and Pueraria thunbergiana, were found to grow vigorously in the studied area. Among them, Artemisia princeps was selected as a possible phytoremediator for cleaning heavy metal contaminated soils. Artemisia princeps contained about 43 and $52mg\;kg^{-1}$ of Cd in their root and shoot as dry weight, respectively. Average contents of Cd in the rhizosphere soil, $15.68mg\;kg^{-1}$, was slightly higher than the soil-root interface soils, $14.1mg\;kg^{-1}$. Sequential extraction of Cd contaminated soils showed that average $2.4mg\;kg^{-1}$ (about 7%) of cadmium existed as exchangeable form and the average amounts increased as follows : adsorbed < organically bound < exchangeable << oxide carbonate << sulfide residual fractions. Amendment of organic by-product fertilizer in metal-contaminated soils promoted the growth of roots significantly as compared with the other treatments containing chemical fertilizer.

• KSBB Journal
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• v.14 no.5
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• pp.585-592
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• 1999

This study was aimed to enhance the Fe(II) oxidation rate using immobilized cells of Thiobacillus ferroxidans. For this purpose, a medium for the minimization of jarosite formation was developed first. Secondly, cell immobilization in celite beads was carried out. And then, repeated-batch and continuous operatons of Fe(II) oxidation by using immobilization cells were performed. In a series of flask cultures, three types of media were tested: media with a much lower salt concentration than that of the 9K medium; media which contained different nitrogen sources from that of the 9K medium, that is $(NH_4)_2HPO_4$, $NH_4Cl and HNO$_3$; media which contained $(NH_4)_2HPO_4$ as nitrogen and phosphate source, but without $K_2HPO_4$ as nitrogen and phosphate source in the 9K medium. As a result, the M16 medium which contained 3 g/L of $(NH_4)_2HPO_4$ as nitrogen and phosphate source was found to be the optimal one. It sustained good cell growth allowing no jarosite formation. In the repeated-batch operations, the rate of Fe(II) oxidation gradually increased to reach a maximum value as the batch was repeated. As a result of repeated-batch operations. a maximum Fe(II) oxidation rate was 2.33 g/L . h. In the continuous operations, the iron oxidation rate could be increased to 2.14 g/L .h at a dilution rate of 0.25 $h^{-1}$ which is greater than the maximum specific growth rate (0.12 $h^{-1}$) of the bacteria.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.28-33
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• 2004

This study was conducted to how the effect of lime and humic acid on cadmium availability and ie uptake by plant grown in contaminated paddy soils with heavy metal. The treatment levels of lime were 2.5 and 5.0 ton/ha and that of humic acid were 1 and 2%. The contents of 0.1N HCl extractable Cd were reduced with lime and humic acid and were negatively correlated with CEC as well as soil pH. The sequential extraction procedure was used to fractionate the heavy metals in soils into the designated from exchangeable (0.5 M $KNO_3$) water soluble ($H_2O$), organically bound (0.5 M NaOH), carbonate (0.05 M $Na_{2-}$ EDTA) and sulfide/residual (4 M $HNO_3$). In soil amended with 2.5 ton/ha lime and 1% humic acia che- mical forms of Cd at tillering stage were predominant exchangeable + water soluble extractable Cd, whereas that at harvesting stage were predominant carbonate + sulfide/residual extractable Cd. The exchangeable forms of Cd in soil with lime and humic acid were negatively correlated with soil pH during the harvesting period. Total absorbed Cd of paddy rice tended to occur in the order of root > stem > leaf > brown rice. Cd contents of brown rice with lime and humic acid treatment were 0.09 and 0.08 mg/kg, respectively. That were lower than control, 0.20 mg/kg. It could be that treatment of lime and humic acid in polluted soil by heavy metals would reduce the uptake of heavy metals by piano and be a temporary method of reclamation at the highly heavy Metal contaminated soils.

• Applied Biological Chemistry
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• v.10
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• pp.1-13
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• 1968

Phytin is a salt(mainly calcium and magnesium) of phytic acid and its purity and molecular formula can be determined by assaying the contents of phosporus, calcium and magnesium in phytin. In order to devise a new method for the quantitative analysis of the three elements in phytin, the chelatometric method was developed as follows: 1) As the pretreatment for phytin analysis, it was ashfied st $550{\sim}600^{\circ}C$ in the presence of concentrated nitric acid. This dry process is more accurate than the wet process. 2) Phosphorus, calcium and megnesium were analyzed by the conventional and the new method described here, for the phytin sample decomposed by the dry process. The ashfied phytin solution in hydrochloric acid was partitioned into cation and anion fractions by means of a ration exchange resin. A portion of the ration fraction was adjusted to pH 7.0, followed by readjustment to pH 10 and titrated with standard EDTA solution using the BT [Eriochrome black T] indicator to obtain the combined value of calcium and magnesium. Another portion of the ration fraction was made to pH 7.0, and a small volume of standard EDTA solution was added to it. pH was adjusted to $12{\sim}13$ with 8 N KOH and it was titrate by a standard EDTA solution in the presence of N-N[2-Hydroxy-1-(2-hydroxy-4-sulfo-1-naphytate)-3-naphthoic acid] diluted powder indicator in order to obtain the calcium content. Magnesium content was calculated from the difference between the two values. From the anion fraction the magnesium ammonium phosphate precipitate was obtained. The precipitate was dissolved in hydrochloric acid, and a standard EDTA solution was added to it. The solution was adjusted to pH 7.0 and then readjusted to pH 10.0 by a buffer solution and titrated with a standard magnesium sulfate solution in the presence of BT indicator to obtain the phosphorus content. The analytical data for phosphorus, calcium and magnesium were 98.9%, 97.1% and 99.1% respectively, in reference to the theoretical values for the formula $C_6H_6O_{24}P_6Mg_4CaNa_2{\cdot}5H_2O$. Statical analysis indicated a good coincidence of the theoretical and experimental values. On the other hand, the observed values for the three elements by the conventional method were 92.4%, 86.8% and 93.8%, respectively, revealing a remarkable difference from the theoretical. 3) When sodium phytate was admixed with starch and subjected to the analysis of phosphorus, calcium and magnesium by the chelatometric method, their recovery was almost 100% 4) In order to confirm the accuracy of this method, phytic acid was reacted with calcium chloride and magnesium chloride in the molar ratio of phytic: calcium chloride: magnesium chloride=1 : 5 : 20 to obtain sodium phytate containing one calcium atom and four magnesium atoms per molecule of sodium phytate. The analytical data for phosporus, calcium and magnesium were coincident with those as determine d by the aforementioned method. The new method employing the dry process, ion exchange resin and chelatometric assay of phosphorus, calcium and magnesium is considered accurate and rapid for the determination of phytin.

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.297-302
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• 2001

To compare the relationship between the vertical distribution of heavy metals in paddy soil and soil pH near four abandoned metal mines, 40 paddy surface soils $(0{\sim}15\;cm)$ and 12 soils with soil depths ($0{\sim}20$, $20{\sim}40$, $40{\sim}60$, $60{\sim}80$ and $80{\sim}100$ cm) were collected. Both total and extractable heavy metal contents in soils were analyzed after acid digestion $(HNO_3:HClO_4:H_2SO_4)$ and 0.1 N-HCl extraction, respectively. The 0.1 N-HCl fraction ratio over total contents of Cd, Cu, Pb, and Zn were 57, 30, 23, and 19% respectively. Vertical distribution of heavy metals varied considerably among the different mines. In Choil mine, there was no difference in concentrations of all the metals with soil layers. However, Cu and Pb contents in Gahak mime were high at $0{\sim}20\;cm$ depth, and Zn was high at $0{\sim}40\;cm$ depth. In Sinyemi mine, Cd and Cu contents were high at $0{\sim}40\;cm$ depth. Cd, Cu, and Pb contents in Okcheon mine were high through all soil profiles up to 100 cm soil depth. The 0.1 N-HCl fraction ratio over total contents of heavy metals with soil layers were very high at $0{\sim}20\;cm$ depth. As soil depth increased, fraction ratio of heavy metals decreased at the high soil pH (Gahak, Sinyemi, and Choil mines). However, the ratios of Cd, Cu, and Pb in Okcheon mine, having a relatively lower soil pH than other sites, were relatively similar through all the soil profiles up to 100 cm soil depth. Therefore, it was estimated that the mobility and availability of heavy metals in soils were affected by soil pH.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.11-17
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• 2003

pH value of sampled fogwater at source regions (above highway and road) in Yongin sites showed the lowest value and was increased after passing the forest stands. Changes of ion concentrations through the forest stands showed a lowering tendency at sampling sites. The fogwater passing the forest stands (Quercus mangolica and Pinus rigida) surrendered acid pollutants to crown and stem from the atmosphere. It was concluded that environmental moisture in the atmosphere is acidified in fogwater. The influence was extended to the pure zone, and the frequency of acid rain has increased. The forests are assumed to remove air pollutants because ion concentrations in fogwater decreased after passing the forests. The fogwater which functions as a local sink for pollutants (H$_2$SO$_4$, HNO$_3$, etc.) falling on plant surfaces is considered to effectively remove acid pollutants. But if the deposition of pollutants exceeds the capacity of purification, it would damage the forest ecosystem. Further investigation is necessary to identify tree species tolerant to acid pollutants.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.525-531
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• 2011

This study was conducted to examine the contents of lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) in meat and meat products in Korea. The contents of Pb, Cd, As, and Hg in 466 samples of beef, pork, chicken, duck, ham, and sausage were measured using inductively coupled plasma mass spectrometry or a mercury analyzer. Wet ashing and microwave method were compared, and the recovery and reproducibility of the microwave method were better than those of wet ashing for meat and meat products. The recovery of the microwave method was 98.1% for Pb, 104.6% for Cd, and 103.4% for As, respectively. The best result was obtained through digestion using an acid mixture ($HNO_3$/$H_2O_2$, 6:2). Hg content was measured using a mercury analyzer. As a result, the contents of Hg and Cd in samples were lower than those of Pb and As. The average contents of Pb were 0.009 mg/kg in beef, 0.010 mg/kg in pork, 0.006 mg/kg in chicken, 0.007 mg/kg in duck, 0.005 mg/kg in ham, and 0.009 mg/kg in sausage. The average Cd contents were 0.0004 mg/kg in beef, 0.0004 mg/kg in pork, 0.0005 mg/kg in chicken, 0.0012 mg/kg in duck, 0.0015 mg/kg in ham, and 0.0019 mg/kg in sausage. The average As contents were 0.016 mg/kg in beef, 0.004 mg/kg in pork, 0.021 mg/kg in chicken, 0.010 mg/kg in duck, 0.014 mg/kg in ham, and 0.018 mg/kg in sausage. The average Hg contents were 0.713 ${\mu}g/kg$ in beef, 0.902 ${\mu}g/kg$ in pork, 0.710 ${\mu}g/kg$ in chicken, 0.796 ${\mu}g/kg$ in duck, 1.141 ${\mu}g/kg$ in ham, and 1.052 ${\mu}g/kg$ in sausage. Based on the results of the National Health and Nutrition Survey 2005, the levels of dietary exposure to heavy metal contaminants in meat and meat products were compared with the provisional tolerable weekly intake(PTWI) established by the Joint FAO/WHO Expert Committee on Food Additives. The average dietary exposure of the general population from meat and meat products was 0.03-0.2% of PTWI for Pb, Cd, As, and Hg, which indicates a safe level for public health at present.