• 대한화학회지
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• 제41권5호
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• pp.256-265
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• 1997

토양과 수질시료 중에서 nitrite, nitrate 그리고 ammonia성 질소를 빠르고 연속적으로 정량할 수 있는 방법에 관하여 연구하였다. 실제시료를 측정하기전에 각 성분의 표준시료를 사용하여 FIA의 구조적 인자(주입 양, 반응코일 길이 그리고 흐름속도)를 결정하였다. Nitrite는 Griess reaction에 의해 sulfanilamide와 반응 후 N-(1-naphthylenediamine dihydrochloride)과 결합하여 azo 색소를 형성시킨 후 540 nm에서 측정하였고, nitrate는 hydrazine을 사용하여 nitride로 환원시킨 후 측정하였다. Ammonia는 Nessler법을 사용하여 440 nm에서 측정하였다. 최적 조건에서 $N(NO_2^-),\;N(NO_3^-)와\;N(NH_4^+)$의 검출한계(S/N=3)는 0.1 ㎍/ML, 0.4 ㎍/mL 그리고 0.3 ㎍/ML이었다. 실제시료를 비색법, ion chromatography 및 FIA로 측정하여 비교한 결과 상호 일치성이 80~125%로 나타내어 만족스러웠다. 시료의 주입횟수는 30회/시간 이상으로 조절할 수 있었다.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E1호
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• pp.23-35
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• 2005

Size distribution of particulate water-soluble ion components was measured at Gosan, Korea using a micro-orifice uniform deposit impactor (MOUDI). Sulfate, ammonium, and nitrate showed peaks in three size ranges; Sulfate and ammonium were of dominant species measured in the fine mode ($D_{p} < 1.8 {\mu}m$). One peak was observed in the condensation mode ($0.218\sim0.532{\mu}m$), and the other peak was obtained in the droplet mode ($0.532\sim1.8{\mu}m$). Considering the fact that the equivalent ratios of ammonium to sulfate ranged from 0.5 to 1.0 in these size ranges, it is inferred that they formed sufficiently neutralized compounds such as ($NH_{4})_{2}SO_{4} and (NH_{4})_{3}H(SO_{4})_{2}$ during the long-range transport of anthropogenic pollutants. On the other hand, nitrate was distributed mainly in the coarse mode ($3.1\sim6.2{\mu}m$) combined with soil and sea salt. Two sets of MOUDI samples were collected in each season. One sample was collected when the concentrations of criteria air pollutants were relatively high, but the other represented relatively clean air quality. The concentrations of sulfate and ammonium particles in droplet mode were the highest in winter and the lowest in summer. When the air quality was bad, the increase of nitrate was observed in the condensation mode ($0.218\sim0.282{\mu}m$). It thus suggests that the nitrate particles were produced through gas phase reaction of nitric acid with ammonia. Chloride depletion was remarkably high in summer due to the high temperature and relative humidity.

• 한국식품위생안전성학회지
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• 제17권2호
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• pp.101-105
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• 2002

질산염 및 아질산염의 주요 급원인 각종 채소류 및 과실류에서 이들의 분포를 조사하고자 엽채류 23종, 과채류 4종, 근채류 $\boxUl$종, 향신채소류 7종 및 과실류 15종의 질산염, 아질산염을 Ion-Chromatography(IC)를 이용하여 분석하였다. 엽채류에서 아질산염은 총 10종에서 검출 되었으며,재래종 상치가 평균 0.6 mg/kg으로 가장 낮은 함량이었고 개량종 상치가 평균 349 mg/kg으로 가장 높은 함량이었다. 질산염은 취나물이 평균 578.3 mg/kg으로 그 함량이 가장 높았으며, 다음이 겨자잎(415.7mg/kg), 청경채(348.6 mg/kg)의 순이었다. 과채류 중 아질산염은 본 실험의 조건에서는 검출되지 않았으며 질산염은 애호박이 평균 86.2 mg/kg으로 가장 높은 함량이었으며 오이가 0.6~24.7 mg/kg(평균 5.5 mg/kg)으로 가장 낮았으나 모든 시료가 개체에 따라 함량의 차이가 컸다. 근채류에서도 아질산염은 검출되지 않았고 질산염은 무가 0.2~ 580.0 mg/kg으로 월등히 높은 함량이었고 향신채소류는 질산염의 함량이 대체로 낮은 반면 마늘을 제외한 전 시료에서 아질산염이 불검출에서 29.8 mg/kg까지 검출되었다. 파의 경우 아질산염은 잔파가 더 높은 함량이었으나 질산염은 대파가 평균 4.3 mg/kg으로 잔파에 비해 약 6배 더 높은 함량이었고, 고추에서도 아질산염은 적고추가 더 높은 함량이었으나 질산염은 청고추가 약 7배나 더 높았다. 과실류의 질산염은 사과가 평균 0.5 mg/kg으로 가장 낮은 함량이었고 자두가 1.6~206.2 mg/kg, 평균 76.6 mg/kg으로 다른 시료에 비하여 월등히 높은 함량이었다.

• 한국대기환경학회지
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• 제12권3호
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• pp.323-332
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• 1996

Precipitation samples were collected by the wet-only sampling method at Seoul from September 1993 to June 1995. Sample were analysed for the anions $(NO_3^-, NO_2^-, SO_4^{2-}, Cl^-, and F^-)$ and cations $(Na^+, K^+, Ca^{2+}, Mg^{2+}, and NH_4^+)$ in addition to pH and electric conductivity. In order to establish the chemical analysis data of high quality, the assurance checks for analytical data of precipitation were performed by considering the ion balance and by comparing the measured conductivity with the calculated conductivity. As we applied the various assurance checking methods by the ion balance used until recently to a data set measured in this study, the f value expressed as $\Sigma C/\Sigma A$ was found to be not appropriate for the data screening. Also, the scattering plot between cations and anions in each sample was found to show the general tendency of ion balance but was proved to not quantitate the standard of data screening at a data set of samples of various concentration levels. The h value defined as (A-C)/C for C $\geq$ A and (A-C)/A for C < A was used to check the ion balance. However, the standard of data screening by h value must very in response to total ion concentration of samples. In this study, the quality assurance of chemical analysis data was checked by considering both the ion balance of evaluating by h value and the conductivity balance. Further the quality control was achieved by these quality assurance methods. As the result, 67 samples among total 77 were obtained as valid. As the central tendency value for a statistical summary in the analytical parametr of samples, the volume-weighted mean value was found to represent more the general chemistry of precipitation rather than the arithmetic mean. The volume-weighted mean pH was 5.0 and 25% of samples was less than this mean. The concentrations of sufate and nitrate in precipitation were 90.4 ueq/L and 32.4 ueq/L which made up 59% and 21% of all anions. The raion of $SO_4^{2-}/(NO_3^- + NO_2^-)$ in precipitation was 2.7, which indicates that the contributions of $H_2SO_4$ and $HNO_3$ to the acidity of precipitation are 70% and 30%, respectively.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권6호
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• pp.29-34
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• 2009

본 연구에서는 질산염(${NO_3}^-$)과 용존산소(DO)에 의한 생물학적 퍼클로레이트 환원의 저해 그리고 전자공여체를 차지하기 위한 이러한 전자수용체들의 경쟁적 관계를 조사하고자 염소이온프로브(chloride ion probe)를 직접적인 측정방법으로 사용하였다. 퍼클로레이트 환원미생물을 포함하는 플라스크에서 염소이온프로브를 이용하여 염소생성 (=퍼클로레이트 환원)을 모니터링하였다. 2 mM 퍼클로레이트의 생물학적 환원은 2 mM의 질산염에 의해 저해를 받았으며, 염소이온 생성율이 퍼클로레이트가 단독으로 존재하는 경우에 비해 30% 정도 감소하였고, 아세테이트가 제한된 상태이며 질산염과 퍼클로레이트가 공존하는 경우는 염소이온의 생성율이 약 70% 정도 감소하였다. 7-8 mg/L의 용존산소와 2 mM의 퍼클로레이트가 공존하는 조건에서 아세테이트의 공급정도와 상관없이 퍼클로레이트의 생물학적 환원작용이 완벽하게 저해를 받았다.

• 한국식품영양학회지
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• 제35권5호
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• pp.313-323
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• 2022

To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.

• 분석과학
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• 제12권2호
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• pp.99-104
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• 1999

자외선검출법과 이온크로마토그래피를 이용하여 소금물 중에 함유하는 몇 가지 음이온의 분리정량에 대하여 검토하였다. 분리관은 음이온교환수지(Dionex, AS7)를 사용하였고 용리액으로서는 sodium chloride/sodium phosphate 완충용액을 사용하였다. 단계적용리법을 적용하므로서 최적분리가 가능하였으며 8가지 음이온(iodate, bromate, nitrite, bromide, nitrate, chromate, iodide와 thiocyanate)이 40분내에 분리되었다. 여러 가지 농도의 NaCl용액(0.0 M-1.0 M)속에 존재하는 음이온들의 거동을 살펴보았다. NaCl의 농도가 진할수록 bromate, nitrite, bromide와 nitrate의 피크의 모양이 점점 넓어졌으나 chromate, iodide와 thiocyanate는 1.0 M NaCl 용액의 농도까지 피크모양이 거의 변하지 않았다. 또한 여러 가지 농도의 NaCl용액에서 음이온들의 검량곡선은 좋은 직선성을 보여주었으며, $50{\mu}L$ 시료용액에서 검출한계는 $10-720{\mu}g/L$ 이었다. 바닷물중의 bromide, nitrate와 iodide의 측정에 이방법을 적용하였다.

• 한국응용과학기술학회지
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• 제34권3호
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• pp.436-442
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• 2017

합성폐수 내의 유기물(COD), 질산성 질소, 인산이온을 제거하기 위한 폐수처리 시스템 개발을 위한 연구를 수행하였다. 먼저 COD는 HClO의 산화 반응에 의해 거의 100 % 제거되었으며 전기화학적 처리에 의해 질산성 질소가 암모니아성 질소로 환원되지만, 암모니아성 질소는 HClO 처리에 의해 질산성 질소로 재 산화 되었다. 암모니아성 질소는 가열 증발 처리에 의하여 거의 100% 제거 되었으며 HClO 처리를 하여도 재 산화되는 암모니아성 질소는 나타나지 않았다. 인산 이온은 pH에 따라 금속 착염을 형성함으로써 침전 처리에 의해 제거할 수 있었으며 전기화학적 처리와 HClO 처리를 통하여 COD 99.5 % 이상, 질소 97.3 %, 인 91.5 %의 제거 효율을 얻을 수 있었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.762-766
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• 2001

The nar promoter of Escherichia coli was known to induce maximally under anaerobic or microaerobic conditions in the presence of nitrate. In this study, the nar promoter was tested to see whether the expression level of a reporter gene which fused lacZ gene at nar promoter's downstream, in the some gram negative host strains(Agrobacterium, Pseudomonas and Rhizobium). A nar promoter system(Combination of nar promoter and gram negative strain) was grown under aerobic conditions to absorbance at 600 nm of nearly 2.0 and then, the nar promoter was induced by lowering DO to 1-2% with alternating microaerobic and aerobic condition in the fermentor cultures, using different gram negative hosts. For a wild type nar promoter (pNW61), it was possible to maintain production of ${\beta}-galactosidase$ activity per cell(specific ${\beta}-galactosidase$ activity) at 14,000, 9600, 45 Miller units in the presence of 1% nitrate. and for a nitrate - independent nar promoter (pNW618) at 12,000, 10,400 and 58 Miller units in the absence of nitrate ion, respectively.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.447-450
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• 2003

The feasibility of PENTANOX 4X for the simultaneous removal of nitrate and phosphate was investigated using micellar-enhanced ultrafiltration. Because PENTANOX 4X has cationic property at low pH, anionic contaminants can be bound to PENTANOX 4X micelle by electrostatic interaction. At pH 3, 90% of nitrate and 72% of phosphate were removed by 27 mM of PENTANOX 4X, which were equivalent to 20 mM of CPC. PENTANOX 4X of > 80 % was rejected by ultrafiltration membrane and did not make any counter-ion such as chloride for CPC which might cause second-pollution.