• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.689-697
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• 2006

Distribution and speciation of arsenic in water resources was investigated in the Ulsan mine area. In 62% of uoundwater samples from the mine area, total As concentrations exceeded 0.05 mg/l, the Korean Drinking Water Standard. As(V) was the major type in groundwater with minor As(III). Arsenic species appeared to be in transition stages following redox changes after exposure to the air through the monitoring wells. In areas around the mine, the mine and Cheongog spring appeared to be the sources of arsenic contamination of water resources. The spring showed 0.345 mg/1-As, as much as seven times of the Korean standard. Groundwater and stream samples showed As-concentrations greater than 0.05 mg/l in 30% and 33% samples, respectively, and 60 and 67% of samples exceeded 0.01 mg/l of WHO guideline, respectively. Again, As(V) was a dominant species, however, several samples had As(III) in appreciable levels. In one stream sample, organic species including DMA and AsB were detected in low levels, probably resulted from transformation or related biogeochemical processes.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.631-638
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• 2010

The objective of this study was to evaluate the efficiency of zerovalent iron and basic oxygen furnace slag on arsenic stabilization in soils. For this, arsenic (V) contaminated soil and roxarsone contaminated soil were incubated after incorporation with zerovalent iron (ZVI) or basic oxygen furnace slage (BOFS) at four different levels (0%, 1%, 3%, and 5%) for 30 days and then the residual concentrations of arsenic were analysed following extraction with aqua reqia, 1N HCl and 0.01 M $CaCl_2$. The total concentration of arsenic was 2,285 mg/kg in the As(V) contaminated soil and 6.5 mg/kg in the roxarsone contaminated soil. 1 N HCl extractable arsenic concentration in the As(V) contaminated soil was initially 1,351 mg/kg and this was significantly declined by 713~1,034 mg/kg following incubation with ZVI while BOFS treatment showed no effect on the stabilization of inorganic arsenate except 5% treatment which showed around 100 mg/kg reduction in 1N HCl extractable arsenic. Similarly, in the roxarsone contaminated soil 1N HCl extractable concentration of arsenic was reduced from 3.13 mg/kg to 0.69 mg/kg with ZVI treatment increased from 1% to 5% while BOFS treatment did not lead to any statistically significant reduction. Available (0.01M $CaCl_2$ extractable) arsenic was initially 0.85 mg/kg in the As(V) contaminated soil and this declined by 0.79 mg/kg following incorporation with 5% ZVI, which accounted for more than 90% of the available As in the control. When As(V)-contaminated soil was treated with BOFS, the available arsenic was increased due to competing effect of the phosphate originated from BOFS with arsenate for the adsorption sites. For the roxarsone contaminated soil, the greater the treatment of ZVI or BOFS, the lower the available arsenic concentration although it was still higher than that of the control.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.266-272
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• 2010

The present study was carried out to assess exposure & risk for Korean by total and inorganic As intake through agricultural products. Total arsenic analysis was performed using microwave device and ICP-MS. 50% MeOH extraction and anion-exchange HPLC-ICP-MS method has been used to determine arsenic species. 329 samples covering 20 kinds of agricultural products were collected from various retail outlets and markets across Korea. The concentration of total As was in the range of 0.001~0.718 mg/kg, while inorganic and organic arsenic species in all samples was not determined. For risk assessment, probable daily intake was calculated and compared with provisional tolerable weekly intake (PTWI, 15 ${\mu}g$/kg b.w./week for inorganic arsenic) established by JECFA. The median daily exposure to total and inorganic As by intake of agricultural products except rice was ranged 0.0002~0.012, 0.0001~0.001 ${\mu}g$/kg b.w./day, corresponding to 0.01~0.5%, 0.002~0.1% of PTWI, respectively. The median level of total and inorganic As intake through rice was 0.603 and 0.041 ${\mu}g$/kg b.w./day, and 28.1% and 1.9% of PTWI, respectively. Therefore, the level of overall exposure to arsenic for Korean through agricultural products was below the recommended JECFA levels, indicating of least possibility of risk.

• Analytical Science and Technology
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• v.36 no.3
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• pp.135-142
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• 2023

The total arsenic and 6 arsenic species were investigated in 56 fish collagen products using ICP-MS (Inductively coupled plasma-mass spectrometer) and HPLC-ICP-MS(High performance liquid chromatography-Inductively coupled plasma-mass spectrometer). The mean concentrations of total arsenic and arsenic species were 40.103±81.133 ㎍/kg (N.D.~586.686) and 30.070±50.378 ㎍/kg (N.D.~313.871), respectively. The mean concentration of inorganic arsenic was 24.610±32.706 ㎍/kg (N.D.~129.331), and the As(V) (Arsenate) was the most dominant. The standards and specifications of arsenic have not been established for fish collagen products. Our study presents that arsenic levels are relatively safe compared with not only previous studies but also domestic and international standards. However, in one sample, the total arsenic concentration was 586.686 ㎍/kg, showing the inorganic was 8.119 ㎍/kg, and the DMA was 305.752 ㎍/kg, which was high than the Canadian standard for organic arsenic. In conclusion, it is necessary to monitor arsenic levels consistently and establish standards and specifications of arsenic in fish collagen products to assure consumer safety.

• Economic and Environmental Geology
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• v.38 no.1
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• pp.23-31
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• 2005

This study was performed to investigate the effect of humic acid on the adsorption of arsenic onto hematite and its binding mechanism through the chemical speciation modeling in the binary system and the adsorption modeling in the ternary system. The complexation modeling of arsenic and humic acid was suitable for the binding model with the basis of the electrostatic repulsion and the effect of bridging metal. In comparison with the experimental adsorption data in the ternary system, the competitive adsorption model from the binary intrinsic equilibrium constants was consistent with the amount of arsenic adsorption. However, the additive rule showed the deviation of model in the opposite way of cationic heavy metals, because the reduced organic complexation of arsenic and the enhanced oxyanionic competition diminished the adsorption of arsenic. In terms of the reaction mechanism, the organic complex of arsenic, neutral As(III) and oxyanionic As(V) species were transported and adsorbed competitively to the hematite surface forming the inner-sphere complex in the presence of humic acid.

• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.55-61
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• 1979

Since rice high yielding practices with blast resistant varieties induced severe and earlier infestation of sheath blight recently, it is strongly suggested to spray at least 10 days earlier than the present recommendation and more than 2 sprays from early July to early August seems to be essential for the efficient control of sheath blight in the future. Among organo-arsenic fungicides, MAFe (Neo Asozin) is known as the most effective and economic as well as with the advantages of free phytotoxicity and safe residure on rice, and applications of the mixed formulation with other fungicide and insecticide is suitable for the one-hit control of rice diseases and insect pests in connection with cooperative mass control system. Present level of arsenic $(As_2O_3)$ residue in .ice is summarized as 0.2ppm to 0.65 ppm in highest average, and there are more possibilities of extensive MAFe fungicide uses for the efficient and economic control of this disease. During the past few years, the acreage of sheath blight control has been extended several times while the increase of the fungicides used for sheath blight showing about 10 times in quantity and mort than 15 times in amount, and also the fungicide cost estimated for the control is differ from 1 to 12 billion 1on by the use of MAFe or antibiotic fungicide in a year.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.1
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• pp.79-85
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• 2011

A study on characteristics for removal of arsenic ion using phosphorylated pine needles was performed. The surface condition of phosphorylated pine needles was confirmed by FT-IR, SEM(Scanning Electron Microscopy) and EDX(Energy Dispersive X-ray). The removal rate of arsenic ion was the highest as about 98% at pH 7. Most absorption for arsenic ion was also completed within 30min and decreased with time and pH of arsenic solution from 6.5 to 2.4.

• Journal of Food Hygiene and Safety
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• v.37 no.6
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• pp.385-393
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• 2022

The contamination level of inorganic arsenic, a human carcinogen, was investigated in 87 grains and 66 processed grain foods. Two inorganic arsenic species arsenite (As(III)) and arsenate (As(V)) and four organic arsenic monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, arsenocholine were analyzed using HPLC-ICP/MS with high separation and sensitivity and ICP/MS was used to quantify total arsenic. Inorganic arsenic was detected in all grains. And the total arsenic in grains consists of about 70-85% inorganic arsenic and about 10-20% DMA. The concentration of inorganic arsenic was high in rice and black rice cultivated in paddy soil with irrigated water, while the miscellaneous grain in field was low. Mean concentration of inorganic arsenic in rice germ, brown rice and polished rice was 0.160 mg/kg, 0.135 mg/kg, 0.083 mg/kg, respectively, indicating that rice bran contains more arsenic. In processed grain foods, inorganic arsenic concentration varied according to the kind of ingredients and content, and the detection amount was high in processed food with brown rice and germ. The arsenic content of all samples did not exceed each standard, but the intake frequency is high and it is considered that continuous monitoring is necessary for food safety.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.223-227
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• 2000

Absorption of Cadmium(Cd) and Arsenic(As) by lettuce following to the change of polyamine content in lettuce were examined to find the effect of these elements on lettuce growth and on the basic resistance mechanism. As the contents of Cd and As were increased in soil, the contents of these elements were significantly increased in lettuce but lettuce growth was decreased. Sequential fractionation experiment of the Cd and As treated soil was shown that exchangeable, dilute acid extractable, and organically bound form, which were more mobile and phyto-available, of Cd were increased by 5.6, 42.9, and 56.7% during a growing season whereas 17.6, 25.0, and 24.1% were increased in case of As, respectively. Specially, the Cd content of leaves and roots in lettuce was positively correlated with exchangeable, dilute acid extractable, and residual form of Cd in the treated soil. However, the As content of roots in lettuce was positively correlated with all chemical forms of As in the treated soil. The contents of putrescine and cadaverine, a kind of polyamine, were also increased in lettuce as both elements were increased in soil.

• Analytical Science and Technology
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• v.18 no.5
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• pp.396-402
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• 2005

We try to look for optimum conditions of pre-reductants like L-Cysteine, KI and $FeSO_4$ when analyzing inorganic arsenic by using hydride generation-atomic absorption spectrometry, and run a comparative study of effect in the analysis of them. Also, we separated and analyzed only inorganic arsenic by using $H_2SO_4$-trap to eliminate organic arsenic which are MMA(monomethylarsonate) and DMA(dimethylarsinate). Under the conditions of mixture acid of 1.8 M HCl and 0.08 M $HNO_3$, arsenic standard solution of 20 ppb have more higher absorbance than without adding acid. In case of L-Cysteine, As(V) completely reduces into As(III) when 0.5 g of L-Cysteine is reacted more than 30 mins. in weak acid condition of approximately 0.07 M $HNO_3$ or HCl. In the event of KI, As(V) completely reduces into As(III) when 3 g of KI is reacted more than 1hour in acid condition of 0.8 M $HNO_3$. On the occasion of $FeSO_4$, the inside of tube is blocked by precipitation by mixture reaction of $NaBH_4$ and $Fe^{2+}$, therefore, comparing to other pre-reductants, reproducibility of efficiency of reducing As(V) to As(III) is low. To evaluate the accuracy of the analytical results, we use NIST SRM 1643C Trace Elements in Water ($82.1{\pm}1.2ng/mL$). The results are satisfactory.