• 한국산업보건학회지
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• 제31권3호
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• pp.255-265
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• 2021

Objectives: The purpose of this study is to analyze the exposure characteristics of inorganic acids. Methods: We analyzed exposure data (n = 363,146) for six inorganic acids (hydrogen fluoride, hydrogen bromide, hydrogen chloride, phosphoric acid, nitric acid, and sulfuric acid) collected between 2017 and 2019 in South Korea. Measurement characteristics and exposure levels (ELs) were analyzed by inorganic acid, industry category, enterprise size, and measurement year. Results: Measurement percentage dominated in time-weighted average (TWA, 91%) compared to short term exposure limit (STEL) and Ceiling. Most of the measurements (79.7%) were collected from the manufacturing category of industry. Medians of ELs were mostly low (≤3% of the threshold limit), with the exception of sulfuric acid (4.6% of TWA and 10.5% of STEL). The percentages of exceeding 1% of the occupational exposure limits (OELs) in TWA were relatively high for sulfuric acid (35.8%) and hydrogen chloride (16.5%) compared to the other acids (4.2%-6.6%). In addition, the percentages of exceeding 1% of OELs in STEL or Ceiling were higher for sulfuric acid (22.9%), hydrogen chloride (12.3%), and nitric acid (8.2%) compared to the other acids (1.2%-1.9%). The small-sized enterprises showed higher ELs in TWA; contrarily, the large-sized enterprises had higher ELs in STEL or Ceiling. Conclusions: The measurement characteristics and ELs identified in this study could be useful for establishing safety and health policies for inorganic acids.

• 자원리싸이클링
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• 제26권1호
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• pp.30-36
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• 2017

양극흙에 함유된 금과 은을 회수하기 위해 무기산(염산, 질산, 황산)과 thiourea 및 thiosulfate에 의한 침출실험을 수행했다. 산화제를 첨가하지 않은 조건에서 금은 무기산용액에 전혀 용해되지 않았다. 3종류의 무기산의 농도가 동일한 조건에서 황산용액에서 은의 침출율이 가장 높았으며, 염산의 농도가 증가함에 따라 $AgCl_2{^-}$의 형성에 따라 은의 침출율이 증가하였다. 한편 주석은 질산용액에 전혀 용해되지 않았으나, 구리, 니켈과 아연은 본 실험조건에서 모두 용해되었다. 황산과 thiourea의 혼합용액에서 금과 은은 모두 용해되었다. Thiosulfate용액에 은의 일부가 용해되었으나, 금은 전혀 용해되지 않았다.

• 한국산업보건학회지
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• 제31권1호
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• pp.22-30
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• 2021

Objectives: The objectives of this study were to develop a quality control protocol of inorganic acids using ion chromatograph and to evaluate analytical proficiency of the legally designated agencies. Methods: This study prepared inorganic acid samples by injecting three anion certified solutions (chloride, nitrate, and sulfate) on the quartz filters. To investigate the storage stability and concentration consistency of the samples, 240 samples for each anion were tested at weeks 0, 2, 4, 8, 12, and 16 while storing at 4℃ and 25℃. To evaluate analytical proficiency, two separate testings were administrated for six skilled analysts and 46 analysts affiliated with legally designated agencies. Results: Average recoveries of the three ions after 16 weeks of storage were fairly high (over 95%). In addition, average recoveries (chloride = 97%, nitrate = 96%, and sulfate = 103%) after 16 weeks of storage at low temperate were relatively higher than those (94%, 93%, and 98%) at room temperature. The coefficients of variation (CV) for the three ions were less than 5% except for the sulfate sample at 5.56 ㎍ (CV = 12.4%). The average ratios of the concentration values analyzed by the legally designated agencies to the injected concentrations were close to 1. However, their CVs were relatively greater (chloride ≤ 49%, nitrate ≤ 14%, and sulfate ≤ 28%), which implies a need for quality control. Conclusions: The quality control protocol used in this study for the three inorganic acids can be utilized in the quality control for ion chromatography.

• Applied Biological Chemistry
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• 제25권3호
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• pp.161-165
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• 1982

홍삼갈변(紅蔘褐變)의 적합(適合)한 촉진방법(促進方法)을 구명(究明)하기 위하여 인삼(人蔘)에 당(糖), amino산(酸) 및 무기질소화합물(無機窒素化合物)을 처리(處理)한 결과(結果) 당류중(糖類中)에서는 maltose와 glucose가 가장 강(强)한 갈변축진작용(褐變促進作用)을 나타내었다. amino산(酸)은 basic amino acid인 lysine, histidine, arginine이 가장 크게 촉진(促進)했으며 당(糖)과 amino산(酸) 혼합처리(混合處理)에서는 glucose와 glutamic acid 혼합처리구(混合處理區)가 가장 크게 촉진(促進)되었다. Glucose농도별(濃度別) 처리시(處理時)의 갈변촉진효과(褐變促進?果)는 glucose농도(濃度)가 증가(增加)함에 따라 갈변(褐變)이 촉진(促進)되었으며 무기질소화합물중(無機窒素化合物中)에서는 $urea>(NH_4)_2HCO_3>CH_3COONH_4$등의 순(順)으로 갈변(褐變)이 촉진(促進)되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권5호
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• pp.10-17
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• 2022

Inorganic acids such as HCl, HNO₃, and H₂SO₄ have been commonly applied to soil washing of heavy metals-contaminated soil due to their cost-effectiveness. However, implementing the 'Chemical Substance Control Act' requires off-site risk assessment of the chemicals used in the soil washing. Therefore, in this study, organic acids or Fe(III)-based washing agents were evaluated to replace commonly used inorganic acids. Ferric removed heavy metals via H⁺ generated by hydrolysis, which is similar to the HCl used in the control group. Oxalic acid and citric acid were effective to remove Cu, Zn, and Cd from soil. Organic acids could not remove Pb because they could form Pb-organic acid complexes with low solubility. Furthermore, Pb could be adsorbed onto the iron-organic acid complex on the soil surface. Ferric could remove exchangeable-carbonate, Fe-Mn hydroxide, and organic matter and sulfides bound heavy metals (F1, F2, and F3). Organic acids could remove the exchangeable-carbonate and Fe-Mn hydroxide bound metals (F1&F2). Therefore, this research shows that the fractionation of heavy metals in the soil and the properties of washing agents should be considered in the selection of agents in the process design.

• 자원환경지질
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• 제40권2호
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• pp.141-151
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• 2007

충북 영동지역에서 산출되는 일라이트를 대상으로 철 성분을 제거하는 실험을 수행하였다. 이는 일라이트 광석에 들어있는 철 성분을 제거하여 백색도를 향상시킴으로써 광석의 활용 가능성을 높여 주는데 있다. 철 성분의 제거 효율성을 평가하기 위해 무기산(황산, 염산), 유기산(L-아스코르브산, 옥살산), 혼합산(무기산+유기산)을 사용하였다. 실험결과 0.15 M L-아스코르브산을 0.5 N 황산에 첨가한 혼합산과의 탈철 반응을 수행한 경우, 60분 반응 시 1.5 wt%의 산화철 성분을 제거하여 가장 높은 효율을 나타내었다. 0.5N황산을 단독으로 사용한 경우에는 60분 반응 시 제거된 산화철이 0.68%에 불과하다. 황산만을 이용하여 1.5wt %의 산화철을 제거하기 위해서는 5N의 반응농도와 150분의 반응시간이 요구되었다. 따라서 친환경적이고, 인체친화적인 L-아스코르브산의 탈철반응이 반응농토와 반응시간에 있어서도 효율적임을 관찰하였다. 산화철 제거 후 일라이트는 백색도가 42%에서 75%로, 색도가 10YR 8/4에서 5Y, 8/1로 향상되어 CBD 처리와 같은 수준으로 증가하였다. 일라이트 입자를 교결하고 있던 산화철이 제거되어 입도가 소폭 감소하였으나 광물학적/물리 화학적 특성은 변화가 관찰되지 않았다.

• KSBB Journal
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• 제24권1호
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• pp.75-79
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• 2009

Coenzyme $Q_{10}$ 고역가 변이주인 Agrobacterium tumefaciens KPU-11-03의 다양한 유기 질소원에 대한 coenzyme $Q_{10}$ 생산량과 coenzyme $Q_{10}$의 구성비율 등을 비교한 결과, CSP 첨가 시 coenzyme $Q_{10}$ 생산량은 212.7 mg/l, 구성비율은 94%로 다른 유기질소원에 비해 매우 높게 나타났다. 특히 Bacto tryptone, Bacto peptone, soybean meal, casamino acid 등의 유기 질소원 첨가 시에는 극히 낮은 coenzyme $Q_{10}$ 역가를 나타내어 균체내의 coenzyme $Q_{10}$의 축적은 유기 질소원의 종류 즉 아미노산의 종류 및 량과 상관성이 있음을 추정할 수 있었다. 또한 무기질소원에 대하여 실험한 결과, $(NH_4)_2SO_4$ 첨가 시에 coenzyme $Q_{10}$역가가 약 2배 증가하였고 다른 무기질소원에 사용 시에는 오히려 감소하였다. Coenzyme $Q_{10}$ 역가와 관련된 아미노산을 확인하기 위해 유기질소원으로 Bacto tryptone을 첨가한 배지에 9가지의 아미노산을 첨가하여 실혐한 결과, 방향족 아미노산인 tyrosine 첨가 시의 coenzyme $Q_{10}$ 생산량은 99.5 mg/l로 비첨가구보다 약 8.2배 증가하였으나 phenylalanine과 tryptophan등의 다른 방향족 아미노산의 첨가 시에는 coenzyme $Q_{10}$ 생산량이 오히려 감소하는 것으로 나타나 tyrosine의 첨가가 coenzyme $Q_{10}$ 역가에 매우 중요함을 확인하였다.

• 한국식품저장유통학회지
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• 제7권1호
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• pp.108-112
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• 2000

Proximate composition , volatile compounds, free amino acids, fatty acids and inorganic compounds in leaf, stem and root of Houttyunia cordata Thunb cultivated from two different area, Bosung and Sunchon , were analyzed. Each part of Houttuynia cordata Thunb from both local area showed moisture contents of 80-84% and crude ash contents of 2.1 ∼2.8%. Crude fat and protein contents were less than 3 % showing slightly higher contents in leaf than in both stem and root . Twenty six volatile compunds were identified from the parts of the plant, the volatile contents were high in the oder of leaf, root and stem. Major volatile compounds were mostly derivatives of decanoic acid ; decanoic acid, 20 tridecanoie, decanal and dodecanoic acid. Of free amino acids in leaf asparagine was the highest, while in stem hydroxyproline, proline and arginine were the major free amino acids. Linoleic acid was the highest in the stem and root, and linolenic acid was highest in leaf. the major minerals of all parts were K, Ca. Mg, P, Fe, Zn and Cu, showing highest with K.

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.543-550
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• 2014

Fat and fatty acids in muscle and adipose tissues are among the major factors influencing meat quality particularly nutritional value and palatability. The present study was carried out to examine the effects of supplementing inorganic selenium (Se), iodine (I) and a combination of both on fatty acid compositions in serum, and supraspinatus (SS), longissimus lumborum (LL), and semitendinosus (ST) muscles in goats. Twenty-four, 7 to 8 months old, Kacang male goats with a mean live weight of $22.00{\pm}1.17kg$ were individually and randomly assigned into four groups of six animals each for 100 d of feeding prior to slaughter. The animals were offered the same concentrate (basal) diet as 1% of body weight with ad libitum amount of fresh guinea grass. The four groups were as follows: T1 (control) - basal diet without supplementation; T2 - basal diet with 0.6 mg Se/kg DM; T3 - basal diet with 0.6 mg I/kg DM; T4 - basal diet with combination of 0.6 mg Se/kg DM and 0.6 mg I/kg DM. The major fatty acids (FAs) detected in the serum were palmitic (C16:0), stearic (C18:0), oleic (C18:1n9) and linoleic (C18:2n-6), while the major FAs in the selected muscles were C16:0, C18:0 and C18:1n9 acids. The main polyunsaturated fatty acids (PUFA) detected in muscles and serum were (CI8:2n-6), linolenic acid (C18:3n-3), and arachidonic acid (C20:4n-6). No significant differences (p>0.05) were observed in the concentration of total saturated fatty acids (SFA) among the four groups. PUFA concentrations in the goats supplemented with Se (T2) were significantly higher (p<0.05) than the goats of the control group (T1). The PUFA: SFA ratio was significantly higher in the animals supplemented with dietary Se (T2) than those of control ones (T1). It is concluded that dietary supplementation of inorganic Se increased the unsaturated fatty acids in muscle. The supplementation of iodine with or without Se had negligible effects on muscle fatty acid content of Kacang crossbred male goats.

• Journal of Ecology and Environment
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• 제35권4호
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• pp.351-358
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• 2012

To investigate the environmental adaptation and ecophysiological characteristics of Suaeda maritima and S. asparagoides under saline conditions, plant growth and density were analyzed according to environmental changes of habitats. The total ion content of soil decreased with time, which was caused by the predominance of exchangeable $Na^+$ and $Cl^-$ in the upper layers. The population of S. maritima was more densely distributed in the region with higher ion contents of $Cl^-$, $Mg^{2+}$, $K^+$ and $Na^+$ than the population of S. asparagoides. Both species were showed a decreased population density according to increases in plant growth. Under the conditions of a salt field, S. maritima and S. asparagoides contained high inorganic ions to maintain low water potential, but low water soluble carbohydrate contents. In the case of free amino acid, S. maritima showed an especially high proline content, and contained rather large amounts of free amino acids, whereas S. asparagoides did not. Both species showed high inorganic ion contents in the leaves, which might be a mechanism of avoiding the ionic toxicity by diluting the accumulated ionic concentration with a high ratio of water content to dry weight. This result suggests that S. maritima seems to adapt to saline conditions by accumulating proline in addition to inorganic ions. S. asparagoides seems to adapt by osmoregulation processes, using inorganic ions rather than free amino acids.