• 분석과학
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• 제11권6호
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• pp.495-498
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• 1998

The effect of high concentration ion matrix on the analysis of low anion concentration in the suppressed ion chromatography was studied. The anions studied were $Br^-$, $NO_3{^-}$, $HPO_4^{2-}$, $SO_4^{2-}$, and $C_2O_4^{2-}$ in the presence of excess NaCl and $CaCl_2$. In this study we suggested that the erroneous results in the suppressed ion chromatographic determination of small concentration of anions were not caused by the interaction of large amount of cation in the suppressor, but by the interaction of cation with concerned anion in the original solution. The error in the analysis of such anion can not be eliminated just by dilution. Therefore, we suggested that standard addition method might be adequate for analyses of those samples.

• Environmental Analysis Health and Toxicology
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• 제8권3_4호
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• pp.1-5
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• 1993

Using mixed incubation of cultured endothelial cells, cultured fibroblasts, neutrophils activated with PMA and paraquat, the production of superoxide anion, $H_2O$$_2$and lipoxygenase metabolites (5-HETE and 12-HETE) of arachidonate was estimated. The results was as follows: 1. Neutrophils activated with PMA was produced superoxide anion,$H_2O_2$and lipoxygenase metabolites (5-HETE and 12-HETE) of arachidonate. 2. Fibroblasts did not alter the production of superoxide anion and $H_2O_2$ by neutrophils, it was markedly reduced by mixed incubation with endothelial cells. 3. Mixed incubation with endothelial cells significantly augmented the production of 5 or 12-HETEs, but fibroblasts did not. 4. Using mixed incubation of endothelial cells, fibroblasts, neutrophils and paraquat (50ug/m1 and 100ug/m1), the production of superoxide anion, $H_2O_2$and HETEs was significantly increased on both cells at low concentration (50ug/m1), but markedly reduced at high concentration (1001g/m1). 5. Paraquat showed concentration dependent effects on arachidonate lipoxygenase metabolism.

• 한국대기환경학회지
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• 제10권2호
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• pp.98-104
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• 1994

Precipitation samples were collected at Kosan, Cheju Island over a period of 6 months An automatic rain sampler was manufactured domestically and installed at Kosan station. All samples were collected on a weekly basis. Samples were analyzed for S $O_4$$^{=}$, N $O_3$$^{[-10]}$ , C $l^{[-10]}$ , N $H_4$$^{+}$, N $a^{+}$, $K^{+}$, $Ca^{++}$, $Mg^{++}$, and pH and specific conductivity. The quality analysis of rain sample data were performed based on ion balance and specific conductivity. The pH of rain samples ranged between 4.6 to 6.6. Bicarbonate ion concentration were included in ion balance and specific conductivity calculations. The sum of cation concentrations were slightly greater than the sum of anion concentrations. Calculated specific conductivity was greater than measured specific conductivity. The most probable explanations for this discrepancy is "an anion too low or anion missing." Two criteria were used to identify outliners. They are 1) the difference between the sum of anion concentrations and cation concentration is more than 50 $\mu$eq./1 and 2) the difference between calculated and measured specific conductivity is more than 25%. Chemical analysis from several samples did not satisfy these quality control criteria. Volume weighted average concentrations were calculated. Dominant free acids in rain samples were N $a^{+}$, C $l^{[-10]}$ , S $O_4$$^{=}$, N $O_3$$^{[-10]}$ ions in order of abundance. Non-seasalt sulfate comprises 76% of total sulfate.sulfate.e.ate.e.

• 원예과학기술지
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• 제30권6호
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• pp.694-699
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• 2012

본 시험은 배양액 내 EC 모형을 구명하기 위해 Rush(2005)의 기본 배양액을 설계하여 Robinson and Strokes(1959)의 등가이온총량에 따라 EC 모형을 추정하고, 양이온과 음이온 및 무기이온간의 EC 변량에 대하여 분석하였다. Steiner(1980)의 경험적 해석을 위해 작물 생육에 최적화된 국내외 130종 배양액을 사용하여 EC 추정 모형을 실증하였다. Rush(2005)의 기본 배양액을 등가이온총량으로 EC 추정한 결과 $R^2$ 값 0.96의 y = 1.33x - 0.23의 신뢰성 높은 회귀모형을 추정하였다. 양이온과 음이온의 농도 변화가 EC의 증감 변화와 일치하지만 그 평면적으로 변화하지 않고 변량폭을 보였다. 그 변화는 기존에 보고된 양이온의 영향보다 음이온의 영향이 더 큰 것으로 나타났는데, 질소 이온과 황이온에 기인한 것으로 생각된다. 이상의 EC 추정 모형을 작물 생육이 최적화된 국내외 130종의 배양액을 이용하여 재확인하였는데, $R^2$ = 0.98의 y = 1.23x - 0.02를 나타냈다. 또한 EC에 대한 양이온과 음이온의 contour 분석에서 적정 배양액 농도 범위로 알려진 EC $1.5-2.5dS{\cdot}m^{-1}$는 양이온 $11meq{\cdot}L^{-1}$ 이상, 음이온 $15meq{\cdot}L^{-1}$ 이상인 것으로 나타났다. 좌측 하단의 $1.5dS{\cdot}m^{-1}$ 저농도와 우측 하단의 $2.5dS{\cdot}m^{-1}$ 고농도에서 타원형 분포를 나타내어 적정 배양액 농도 범위에서 양이온과 음이온은 다양하게 분포하는 것으로 나타났다. 본 연구는 Steiner(1980)의 mutual ratio에서 이온 간 함량 비율에 의한 배양액 설계와 달리 EC에 대한 양이온과 음이온의 변량을 동시에 적용함으로써 이온간의 분포 특성과 적정 배양액 농도 EC $1.5-2.5dS{\cdot}m^{-1}$의 양이온과 음이온의 수준을 추정할 수 있는 EC 모형을 제시하였다.

• 한국환경과학회지
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• 제5권2호
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• pp.141-152
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• 1996

This study is an attempt to investigate the chemical components of precipitation and its variation according to surface wind. Precipitation samples were collected by an wet-only precipitation sampler during the period of October 1994 to September 1995 at Kyungsan in Korea. The results obtained in t체s study are summerized as follows. The annual average of precipitation pH is 5.0, the highest month of pH is July of 5.5, and the lowest month of pH is December of 4.4. The most frequent appearance is in the range of pH 5.0 to 5.5 and its rate is 56.8%, The order of ion concentration In precipitation is SO42->NO3->Cl- in case of anion and $Ca^{2+}$>$NH_4^{+}$>$Na^+$>$Mg^{2+}$ in case of cation. It is found from our analysis that the correlation coefficient among the precipitation pH and ion components is below r=0.3, while the correlation coefficient between $SO_4^{2-}$ and NO_3^{-}$, $Na^+$ and $Cl^+$ is above r=0.8, respectively. The mean pH of precipitation is 4.8 under the westerly wind and 5.2 under the easterly wind. The concentrations of anion and cation under the westerly wind are more than the concentrations under the easterly wind. In autumn, the concentration of Na+ and $Cl^+$ under the easterly wind are higher than the concentration under the westerly wind. The correlation coefficients between wind speed and pH, ion components show very low correlation of -0.41 r 0.2. But the present study show that the correlation coefficient between wind speed and pH of precipitation is positive and the correlation coefficients between wind speed and ion concentration is negative.

• 한국건축시공학회지
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• 제23권3호
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• pp.221-229
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• 2023

본 연구에서는 모르타르 내 침투 염화물과 황산염 분석을 단면 깊이별 용출액을 대상으로 음이온교환막(AEM)과 LIBS를 활용하여 수행하였다. 염화물(황산염) 농도별로 침지한 모르타르를 대상으로 IC 분석과 LIBS 분석을 동시에 진행하였다. 실험 결과로, Cl(837.59nm) 및 S(921.3nm)의 파장에서 AEM은 동일 침투 농도에서 paper substrate보다 높은 LIBS 강도가 측정되었고, LIBS 강도와 Cl농도 사이의 높은 상관관계가 확인되었다. 동일 깊이 IC 분석 농도 결과와 비교할 때, AEM을 활용하여 높은 강도를 얻을 수 있었다. AEM을 통해 저농도 구간의 LIBS 강도 향상과 오차 저감을 확인하였으나, S(921.3nm)의 경우는 저농도 구간에 대한 LIBS 신호 감도의 향상이 향후 필요할 것으로 보인다.

• 한국대기환경학회지
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• 제9권2호
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• pp.147-153
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• 1993

From March 1990 to August 1991, every each 5mm bulk precipitation samples were collected at one residental area in Taejon City to investigate chemical characteristics of acid rain. Major ion concentrations of rain samples $(pH, SO_4^{2-}, NO_3^-, CL^-, NH_4^+, Na^+, K^+, Ca^{2+}, Mg^{2+})$ were analysed and compared with the concentration of air pollutants (T. S. P, $SO_2, NO_x$) that were measured by Ministry of Environment. The results of statistical analysis are as followings. Rain pH was relatively high on October and January and relatively low on August, November and February. Major anion is sulfate, and it's concentration is 2.36 times higher than nitrate's, and major cations are ammonium, sodium and calcium ion. Monthly variation of sulfate and calcium concentrations are higher than the others. Ion concentration and rain pH were correlated negatively with rainfall amount. Major ions in rain samples were $SO_4^{2-}, NO_3^-, NH_4^+, Ca^{2+}$ and regression equations are proposed by multiple regression of measured data. Also, regression equation between air pollutants(T. S. P, $SO_2$) and $SO_4^{2-}, Na^+, K^+, Ca^{2+}, Mg^{2+} ions in rain samples were made. From this wer can predict rain pH.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.133-142
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• 2011

A total of 247 samples were collected from groundwater being used for drinking-water supply, and hydrogeochemistry and radionuclide analysis were performed. In-situ analysis of groundwaters resulted in ranges of $13.7{\sim}25.1^{\circ}C$ for temperature, 5.9~8.5 for pH, 33~591 mV for Eh, $66{\sim}820{\mu}S/cm$ for EC, and 0.2~9.4 mg/L for DO. Major cation and anion concentrations of groundwaters were in ranges of 0.5~227.6 for Na, 1.0~279.3 for Ca, 0.0~9.3 for K, 0.1~100.1 for Mg, 0.0~3.3 for F, 0.9~779.1 for Cl, 0.3~120.4 for $SO_4$, 0.0~27.4 for $NO_3$-N, and 6~372 mg/L for $HCO_3$. Uranium-238 and radon-222 concentrations were detected in ranges of N.D-$131.1{\mu}g/L$ and 18-15,953 pCi/L, respectively. In case of some groundwaters exceeding USEPA MCL level ($30{\mu}g/L$) for uranium concentration, their pH ranged from 6.8 to 8.0 and Eh showed a relatively low value(86~199 mV) compared to other areas. Most groundwaters belonged to Ca-(Na)-$HCO_3$ type, and groundwaters of metamorphic rock exhibited the highest concentration of Na, Mg, Ca, Cl, $NO_3$-N, U, and those of plutonic rock showed the highest concentration of $HCO_3$, and Rn. Uranium and fluoride from granite areas did not show any correlation. However, uranium and bicarbonate displayed a positive relation of some areas in plutonic rocks($R^2$=0.3896).

• Journal of Electrochemical Science and Technology
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• 제2권1호
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• pp.8-13
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• 2011

Interfacial compatibility between the Si-Cu electrode and diluted ionic liquid electrolyte containing 50 vol.% of 1M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide (MPP-TFSI) and 50 vol.% dimethyl carbonate (DMC) in a lithium cell and dilution effect on surface chemistry are examined. ex-situ ATR FTIR analysis results reveal that the surface of the Si-Cu electrode cycled in the diluted ionic liquid electrolyte is effectively passivated with the SEI layer mainly composed of carboxylate salts-containing polymeric compounds produced by the decomposition of DMC. Surface species by the decomposition of TFSI anion and MPP cation are found to be relatively in a very low concentration level. Passivation of electrode surface with the SEI species contributes to protect from further interfacial reactions and to preserve the electrode structure over 200 cycles, delivering discharge capacity of > 1670 $mAhg^{-1}$ and capacity retention of 88% of maximum discharge capacity.

• 한국발생생물학회지:발생과생식
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• 제4권2호
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• pp.203-213
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• 2000

본 연구에서는 반응성 산소족이 수정능력획득, 칩체반응에 미치는 영향을 알아보고자 반응성 산소족으로 superoxide anion은 xanthine (X) -xanthine oxidase (XO) system을, hydroperoxide는 $H_2O$$_2$를 농도별로 처 리하였으며, nitric oxide (NO)는 NO donor인 sodium nitroprusside (SNP)를 처리하였다 또한 남성불임요인의 하나로 알려진 leukocytospermia에 대한 영향을 알아보기 위해 lymphocyte를 농도별로 처리하였고, 일반적인 배양기내 산소농도인 20% $O_2$농도를 생체내 농도와 유사한 5% $O_2$ 농도로 낮추었을 때 의 결과를 알아보고자 하였다. 수정능력 획득 정도와 첨체반응률을 알아보기 위해 chlortetracycline (CTC) 염색방법을 이용하였다. 지질과산화 정도는 정자내 malondialdehyde (MDA)의 생성량을 흡광기를 이용하여 정량하였다. $H_2O$$_2$, X-XO, SNP와 lymphocyte 처리군은 1시간 배양시에 수정능력획득률이 유의하게 증가하였으나, 저산소처리군에서는 차이가 없었다. 저 농도의 $H_2O$$_2$를 처리한 경우에는 지질과산화 정도가 감소하였으나, 고 농도에서는 대조군에 비해 유의하게 증가하였다. 고 농도의 Iymphocyte를 처리한 경우에는 1시간 처리시에 지질과산화가 유의하게 증가하였으나, 처리된 산소농도에 따른 지질과산화의 차이는 없었다. 첨체반응률의 경우, 처리한 모든 반응성 산소족에서 대조군에 비해 높은 첨체반응률을 확인하였다. X(100 $\mu$M)-XO(100mIU)의 경우가 가장 높은 첨체반응률을 나타내었다. 이러한 결과들은 반응성 산소족이 수정능력획득, 지질과산화 그리고 첨체반응에 영향을 미치는 것을 확인하여 주었다. 또한 반응성 산소족이 생성된 경우에 수정능력획득이 보다 빠르게 진행되어지는 것은 반응성 산소족이 정자의 과운동성과 수정능력획득의 중요한 조절자임을 시사한다고 사료된다.