• Title/Summary/Keyword: Volume calibration

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Quantitative Analysis of Vitamin B5 and B6 Using High Performance Liquid Chromatography (고속액체크로마토그래피를 이용한 비타민 B5 및 B6의 정량 분석)

  • Kim, Gi-Ppeum;Hwang, Young-Sun;Choung, Myoung-Gun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.10
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    • pp.1186-1194
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    • 2017
  • Recently, many people have demanded reliable nutritional data even for minor-components. On the other hand, an analytical method for the analyses of vitamin $B_5$ and $B_6$ is lacking. Therefore, this study attempted to validate with accuracy and precision the analysis of vitamin $B_5$ and $B_6$ using a high-performance liquid chromatography (HPLC) method. The vitamin $B_5$ and $B_6$ contents were analyzed using an Agilent 1260 series HPLC system. YMC-Pack ODS-AM ($250{\times}4.6mm$ I.D.) and YMC-Pack Pro RS $C_{18}$ ($250{\times}4.6mm$ I.D.) columns were used for the analyses of vitamin $B_5$ and $B_6$, respectively. In the case of vitamin $B_5$, the flow rate was set to 1.0 mL/min by isocratic elution using the 50 mM $KH_2PO_4$ solution (pH 3.5)/acetonitrile (ACN) (95:5, v/v) with monitoring at 200 nm using HPLC/DAD, whereas the flow rate for vitamin $B_6$ was set to 1.0 mL/min of flow rate by isocratic elution using a 20 mM $CH_3CO_2Na$ solution (pH 3.6)/ACN (97:3, v/v) with monitoring by excitation at 290 nm and emission at 396 nm using HPLC/FLD. The column temperature was set to $30^{\circ}C$. The injection volume was $20{\mu}L$ for each experiment. The specificity of the accuracy and precision for vitamin $B_5$ and $B_6$ were also validated by HPLC. The results showed high linearity in the calibration curve for vitamin $B_5$ ($R^2=0.9998^{{\ast}{\ast}}$), the limit of detection (LOD) and limit of quantitation (LOQ) were 0.4 mg/L and 1.3 mg/L, respectively, In contrast, for the calibration curve of vitamin $B_6$, which showed high linearity ($R^2=0.9999^{{\ast}{\ast}}$), the LOD and LOQ were 0.006 mg/L and 0.02 mg/L, respectively.

Calibration of crop growth model CERES-MAIZE with yield trial data (지역적응 시험 자료를 활용한 옥수수 작물모형 CERES-MAIZE의 품종모수 추정시의 문제점)

  • Kim, Junhwan;Sang, Wangyu;Shin, Pyeong;Cho, Hyeounsuk;Seo, Myungchul
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.20 no.4
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    • pp.277-283
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    • 2018
  • The crop growth model has been widely used for climate change impact assessment. Crop growth model require genetic coefficients for simulating growth and yield. In order to determine the genetic coefficients, regional growth monitoring data or yield trial data of crops has been used to calibrate crop growth model. The aim of this study is to verify that yield trial data of corn is appropriate to calibrate genetic coefficients of CERES-MAIZE. Field experiment sites were Suwon, Jinju, Daegu and Changwon. The distance from the weather station to the experimental field were from 1.3km to 27km. Genetic coefficients calibrated by yield trial data showed good performance in silking day. The genetic coefficients associated with silking are determined only by temperature. In CERES-MAIZE model, precipitation or irrigation does not have a significant effect on phenology related genetic coefficients. Although the effective distance of the temperature could vary depending on the terrain, reliable genetic coefficients were obtained in this study even when a weather observation site was within a maximum of 27 km. Therefore, it is possible to estimate the genetic coefficients by yield trial data in study area. However, the yield-related genetic coefficients did not show good results. These results were caused by simulating the water stress without accurate information on irrigation or rainfall. The yield trial reports have not had accurate information on irrigation timing and volume. In order to obtain significant precipitation data, the distance between experimental field and weather station should be closer to that of the temperature measurement. However, the experimental fields in this study was not close enough to the weather station. Therefore, When determining the genetic coefficients of regional corn yield trial data, it may be appropriate to calibrate only genetic coefficients related to phenology.

Simultaneous analysis of 12 kind maker components in Banhabaekchulchhonma-tang by RP-HPLC (RP-HPLC를 이용한 반하백출천마탕에서 12종 지표성분의 동시분석)

  • Lee, Kwang Jin;Yang, Hye Jin;Ma, Jin Yeul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.7
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    • pp.4682-4691
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    • 2014
  • Banhabaekchulchhonma-tang is a traditional Korean herbal prescription with a range of pharmacological activities. In this study, the simultaneous analysis of 12 kinds of marker components, Homogentisic acid, Hesperidin, Naringin, Alisol A, Atractylenolide II, Atractylenolide III, Ginsenoside Rg1, Formononetin, Gastrodin, Berberine, Palmatine and 6-gingerol, in Banhabaekchulchhonma-tang was performed using high-performance liquid chromatography (RP-HPLC). The standard sample of commercial $C_{18}$ reversed phase-column using water (0.1% TFA) and acetonitrile as the mobile phase with a step gradient elution mode. The flow rate (1.0mL/min), injection volume ($10{\mu}L$) and column oven temperature ($40^{\circ}C$) at a 200, 220, 280 and 340nm wavelength was conducted. All calibration curves of the standard components showed good linearity ($r^2$ >0.999). In addition, the limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.012 to $0.878{\mu}g/mL$ and 0.009 to $0.290{\mu}g/mL$. The precision intra-day and inter-day were ranged from 0.07 to 1.21% and 0.20 to 0.90%, respectively. The recoveries ranged from 97.17 to 108.40%. Each sample amount showed a very small change. These results highlight the efficient quality evaluation of Banhabaekchulchhonma-tang.

Determination of Betaine in Fructus Lycii Using Hydrophilic Interaction Liquid Chromatography with Evaporative Light Scattering Detection

  • Shin, Hyun-Du;Suh, Joon-Hyuk;Kim, Jung-Hyun;Lee, Hye-Yeon;Eom, Han-Young;Kim, Un-Yong;Yang, Dong-Hyug;Han, Sang-Beom;Youm, Jeong-Rok
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.553-558
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    • 2012
  • A simple new method was developed for the determination of betaine in Fructus Lycii using hydrophilic interaction liquid chromatography with evaporative light scattering detection (HILIC-ELSD). Good chromatographic separation and reasonable betaine retention was achieved on a Kinetex HILIC column ($2.1{\times}100mm$, $2.6{\mu}m$) packed with fused-core particle. The mobile phase consisted of (A) acetonitrile and (B) 10 mM ammonium formate (pH 3.0)/acetonitrile (90/10, v/v). It was used with gradient elution at a flow rate of 0.7 mL/min. The column temperature was set at $27.5^{\circ}C$ and the injection volume was $10{\mu}L$. The ELSD drift tube temperature was $50^{\circ}C$ and the nebulizing gas (nitrogen) pressure was 3.0 bar. Stachydrine, a zwitterionic compound, was used as an internal standard. Calibration curve over $10-250{\mu}g/mL$ showed good linearity ($R^2$ > 0.9992) and betaine in the 70% methanol extract of Fructus Lycii was well separated from other peaks. Intraand inter-day precision ranged from 1.1 to 3.0% and from 2.4 to 5.3%, respectively, while intra- and inter-day accuracy ranged from 100.0 to 107.0% and from 94.3 to 103.9%, respectively. The limit of quantification (LOQ) was $10{\mu}g/mL$ and the recoveries were in the range of 98.2-102.7%. The developed HILIC-ELSD method was successfully applied to quantitatively determine the amount of betaine in fourteen Fructus Lycii samples from different locations, demonstrating that this method is simple, rapid, and suitable for the quality control of Fructus Lycii.

Simultaneous Analysis of Bangpungtongseong-san and Its Antioxidant Effect (방풍통성산의 동시분석 및 항산화 효능 연구)

  • Seo, Chang-Seob;Kim, Ohn Soon;Shin, Hyeun-Kyoo
    • Herbal Formula Science
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    • v.21 no.2
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    • pp.133-143
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    • 2013
  • Objectives : We carry out the simultaneous quantification for quality control of four components in Bangpungtongseong-san (BPTSS) sample. In addition, we assessed the antioxidant effects of BPTSS sample. Methods : The used column for separation and analysis of four compounds was Luna C18 column and column oven temperature was maintained at $40^{\circ}C$. The mobile phase for simultaneous determination consisted of two solvent systems, 1.0% acetic acid in water and 1.0% acetic acid in acetonitrile. High performance liquid chromatography-photodiode array (HPLC-PDA) method for analysis was performed at a flow rate of 1.0 mL/min with PDA detection at 254 and 280 nm. The injection volume was 10 ${\mu}L$. The antioxidant activities of BPTSS were evaluated by measuring free radical scavenging activities on 2,2'-Azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 1-1-diphenyl-2-picrylhydrazyl (DPPH). The inhibitory effects on low-density lipoprotein (LDL) oxidation were evaluated by the formation of thiobarbituric acid relative substances (TBARS) and relative electrophoretic mobility (REM). Results : Calibration curves were acquired with $r^2{\geq}0.9999$. The values of limit of detection (LOD) and quantification (LOQ) were 0.06-0.29 ${\mu}g/mL$ and 0.20-0.98 ${\mu}g/mL$, respectively. The amounts of geniposide, liquiritin, baicalin, and glycyrrhizin in BPTSS were 5.06, 7.33, 27.56, and 7.81 mg/g, respectively. The BPTSS showed the radical scavenging activity in a dose-dependent manner. The concentration required for 50% reduction (RC50) against ABTS and DPPH radicals were 72.51 ${\mu}g/mL$ and 128.49 ${\mu}g/mL$. Furthermore, GMGHT reduced the oxidation properties of LDL induced by CuSO4. Conclusions : The established HPLC-PDA method will be helpful to improve quality control of BPTSS. In addition, BPTSS has potentials as therapeutic agent on anti-atherosclerosis.

Some considerations for the determination of carbonyl compounds in air: Reaction characteristics of formaldehyde with 2.4-DNPH (대기 중 카보닐 계열 성분의 분석기법의 연구: 포름알데하이드와 DNPH의 반응 특성을 중심으로)

  • Hong, Y.J.;Kim, K.H.
    • Analytical Science and Technology
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    • v.18 no.1
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    • pp.43-50
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    • 2005
  • A number of carbonyl compounds including formaldehyde and acetaldehyde are well known for their toxicity and irritancy. Hence, acquisition of both qualitative and quantitative tool for their analysis is essential to resolve issues associated with malodor or indoor pollution. Using HPLC/UV method, we examined various aspects involved in the measurements of formaldehyde in environmental samples. The results of our analysis indicated that its detection was made as low as 0.5 ppb (assuming 5 L of sample volume), while its precision was maintained near 2% in terms of relative standard error (RSE). When the stability of calibration was checked by variability of slope values obtained over long-term period (e.g., one month), its values were found to remain constantly with RSE values of 3%. It was also found that liquid-phase reaction between formaldehyde and DNPH proceed very slowly to attain equilibrium (one and half hour), while requiring adequate amount of DNPH to form their derivatives. The overall results of our study thus suggest that there are a number of factors to consider for the accurate analysis of formaldehyde in ambient air.

The study for VOCs analysis in long path by open path FT-IR spectrometer (Open path FT-IR spectrometer를 사용한 원거리의 VOCs 측정에 관한 연구)

  • Cho, Nam Wook;Cho, Won Bo;Kim, Hyo Jin
    • Analytical Science and Technology
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    • v.27 no.2
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    • pp.108-113
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    • 2014
  • The harmful materials as volatile organic compounds (VOCS) that is easy for gas to be changed from liquid on ambient temperature, those should be controlled by Korea Chemicals Management Association. The VOCs samples should be collected directly in place so that those could be analyzed. Generally but it couldn't avoid to have the risk of analyst. Moreover, if there is the place limited to entrance, it is impossible to collect directly and measure. Owing to such problem, it tried to be solved by open path FT-IR spectrometer that could be studied on the combustion gases within long path and VOCs samples were tried to measure to large volume by remote and real time. Firstly, it was to investigate optimized measured length between the system and benzene sample of VOCs. As result, The optimized measured length was confirmed with 15 meter length and the qualitative analysis could be measured on seven VOC samples. The calibration curve as quantitative analysis of benzene samples could be worked. On the basis of the result, the system as remote monitor could show to have potentiality.

Morphological Change of Precipitated Calcium Carbonate by Reaction Rate in Bubble Column Reactor (기포탑 반응기에서 반응 속도에 따른 침강성 탄산칼슘의 모폴로지 변화)

  • Hwang, Jung Woo;Lee, Yoong;Lee, Dong Hyun
    • Korean Chemical Engineering Research
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    • v.47 no.6
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    • pp.727-733
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    • 2009
  • Effects of $Ca(OH)_2$ concentration(0.16~0.64 wt%), total volumetric flow rate(3~6 L/min) and $CO_2$ volume fraction(0.3~0.6) on morphology of the precipitated $CaCO_3$ and the mean particle size of the precipitated $CaCO_3$ were investigated in the slurry bubble column reactor. Experiments were carried out in acrylic reactor($0.11m-ID{\times}1.0m-high$) with a internal tube($0.04m-ID{\times}1.0m-high$). The calibration curve on the mass ratio of $CaCO_3$ to $Ca(OH)_2$ was obtained by FT-IR for the conversion of $Ca(OH)_2$ with the reaction time. The reaction rate of $Ca(OH)_2$ increased with increasing the volumetric flow rate of $CO_2$. From SEM images, the crystal size of $CaCO_3$ increased with increasing the reaction rate in the saturated concentration of $Ca(OH)_2$ (0.16 wt%). In addition, the crystal size of precipitated $CaCO_3$ decreased with increasing the concentration of $Ca(OH)_2$, but the mean particle size of precipitated $CaCO_3$ increased with increasing the concentration of $Ca(OH)_2$.

Vegetation Cover Type Mapping Over The Korean Peninsula Using Multitemporal AVHRR Data (시계열(時系列) AVHRR 위성자료(衛星資料)를 이용한 한반도 식생분포(植生分布) 구분(區分))

  • Lee, Kyu-Sung
    • Journal of Korean Society of Forest Science
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    • v.83 no.4
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    • pp.441-449
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    • 1994
  • The two reflective channels(red and near infrared spectrum) of advanced very high resolution radiometer(AVHRR) data were used to classify primary vegetation cover types in the Korean Peninsula. From the NOAA-11 satellite data archive of 1991, 27 daytime scenes of relatively minimum cloud coverage were obtained. After the initial radiometric calibration, normalized difference vegetation index(NDVI) was calculated for each of the 27 data sets. Four or five daily NDVI data were then overlaid for each of the six months starting from February to November and the maximum value of NDVI was retained for every pixel location to make a monthly composite. The six bands of monthly NDVI composite were nearly cloud free and used for the computer classification of vegetation cover. Based on the temporal signatures of different vegetation cover types, which were generated by an unsupervised block clustering algorithm, every pixel was classified into one of the six cover type categories. The classification result was evaluated by both qualitative interpretation and quantitative comparison with existing forest statistics. Considering frequent data acquisition, low data cost and volume, and large area coverage, it is believed that AVHRR data are effective for vegetation cover type mapping at regional scale.

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Measurement conditions for cadmium in urine by flame atomic absorption spectrophotometry (불꽃원자 흡수광법에 의한요중 카드뮴 배설량 측정의 지적조건)

  • Choi, Ho-Chun;Chung, Kyou-Chull
    • Journal of Preventive Medicine and Public Health
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    • v.17 no.1
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    • pp.269-279
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    • 1984
  • The optimum conditions for measuring cadmium content of less than 0.2ppm by flame atomic absorption spectrophotometry were investigated. The cadmium in urine was extracted by APDC-MIBK for the analysis by atomic absorption spectrophotometry after ashing them by a wet method. 1. Optimum conditions by APDC-MIBK and DDTC-MIBK extractions. The acidic aqueous solution was prepared with appropriate amount of 0.IN nitric acid, 5ml of 25% (W/V) sodium potasstum tartarate, 10ml of saturated ammonium sulfate, and 2ml of 2% APDC(or 1 ml of 5% DDTC) chelating agent. The total volume of solution was adjusted to 55 ml and pH to $2{\sim}10$ (or$7{\sim}10$). The aqueous solution was extracted with 10ml MIBK. Concentration of Triton X-100 did not effect the absorbance for APDC-MIBK extraction of cadmium, but absorbance decreased as the concentration increased for DDTC-MIBK extraction. The sensitivity and detection limits for the cadmium determination from APDC-MIBK extraction were 0.0038ppm and 0.0102, 0.0022ppm and 0.0116 for DDTC-MIBK, and 0.0132ppm and 0.0034 for 0.1N nitric acid. APDC-MIBK and DDTC-MIBK extractions were 3 times higher than 0.1N nitric acid for the sensitivity. 2. Excretion of cadmium in 24-hour urine by APDC-MIBK extraction. Determination of cadmium in urine by atomic absorption spectrophotometry of A.A. (Cd=2 mA) mode and B.C. (Cd=4 mA) mode and B.C. (Cd=4mA, $D_2=20mA$) mode showed some difference (p<0.05). The difference of cadmium determination and recovery according to method of standard additions and standard calibration curve method in urine was not significant (p>0.05, $93.48{\pm}11.78%,\;94.83{\pm}22.00%$). Excretion of cadmium in 24-hour urine collection from normal person and variance analysis within measurement variation was not significant (p>0.05), but between interindividual was significant (0.05). Determination of cadmium content by two different methods of flame atomic absorption spectrophotometry and dithizone colorimetry showed that the results from the two methods can be described by a regression line with a good correlation (y=1.0153x-0.2927, x=Cd by D.C., y=Cd by A.A.S., $r=0.8651^*$, p<0.01).

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