• 한국연초학회지
• /
• 제28권2호
• /
• pp.144-151
• /
• 2006

A measurement uncertainty for analysis of volatile organic compound (benzene) in cigarette mainstream smoke was carried out. In this study one point re-calibration method was used to estimate uncertainty for benzene. The measurement uncertainty was calculated based on the uncertainty sources of each analysis step, quality appraisal sources, drift and repeatability. As a result, the concentration and expanded uncertainty of benzene in cigarette mainstream smoke were measured as $38.08{\pm}4.36{\mu}g/cig$. Relative uncertainty of drift and repeatability obtained were 5% and 3%, respectively.

• 한국축산식품학회지
• /
• 제43권6호
• /
• pp.949-960
• /
• 2023

This research aimed to validate a high-performance liquid chromatography method for the quantitative determination of bixin and norbixin in various foods. The Diode Array Detector (495 nm) technique was used. Method was validated for specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy, and the measurement uncertainty was assessed. The calibration curve showed excellent linearity (r²≥0.9999) over the tested concentration range of 0.2-25 mg/L. The LOD and LOQ were 0.03-0.11 and 0.02-0.05 mg/L for bixin and norbixin, respectively. The intra-and inter-day accuracies and precisions were 88.0±1.3-97.0±0.5% and 0.2%-2.6% relative SD (RSD) for bixin and 88.2±0.8-105.8±0.8% and 0.3%-2.7% RSD for norbixin, respectively. Inter-laboratory validation for accuracy and precision was conducted in three laboratories, and these results all met the AOAC guidelines. In addition, the relative expanded uncertainty (<22%) satisfied the CODEX recommendation. Furthermore, products distributed in Korea were monitored for annatto extracts using the proposed method to demonstrate its application. The developed analytical method is reliable for quantifying bixin and norbixin in various foods.

• 한국진공학회지
• /
• 제10권2호
• /
• pp.173-181
• /
• 2001

1,333 Pa 용량의 용량형진공계를 저진공 국가표준기인 초음파간섭 수은주압력계(ultrasonic interferometer manometer)를 이용하여 교정하였다. 이 결과의 불확도를 국제표준화기구의 권고안의 A형 불확도, B형 불확도, 합성표준불확도, 확장불확도 등으로 구분하여 평가하였다. 표준압력 1.76 Pa~1.31$\times$$10^3$Pa에서의 합성표준불확도는 $1.38 \times10^{-2}\; Pa\sim3.03 \times10^{-1} $Pa이었으며, 상대불확도(합성표준불확도/표준압력)는 $2.3 \times 10^{-4}\;Pa\sim7.9 X\times10^{-3} $Pa 이었다.

• 분석과학
• /
• 제19권6호
• /
• pp.490-497
• /
• 2006

액화 천연가스(LNG) 공정 분석 결과의 불확도 요인을 평가하였다. 평가된 불확도 요인은 측정 반복성, 사용된 GC의 비 직선성, 사용된 표준가스의 불확도, 시료 채취 방법에 따른 농도 변화 그리고 교정 후의 기기 변동이었으며, 이 중에서 중요한 불확도 요인은 사용된 GC의 비 직선성, 사용된 표준가스의 불확도 그리고 교정 후의 기기 변동이었다. 주요 성분인 메탄 및 에탄의 경우, 각각 $90.0{\pm}0.9%mol/mol$(확장불확도, 95% 신뢰 수준) 및 $6.26{\pm}0.08%mol/mol$(확장불확도, 95% 신뢰 수준)이었다. 가스 성분원소별로 각 불확도 요소의 기여 정도는 차이가 있었고, 메탄 분석의 경우 사용된 GC의 비 직선성의 상대 표준불확도가 0.28%, 사용된 표준가스의 상대 표준불확도가 0.25%, 그리고 교정 후의 기기 변동에 의한 상대 표준불확도가 0.24%이었다.

• 대한환경공학회지
• /
• 제30권11호
• /
• pp.1123-1131
• /
• 2008

본 연구는 대기 중 PM2.5의 미량금속 중 As을 중성자방사화분석법을 이용하여 분석할 때 발생되는 측정불확도를 ISO GUM 방법과 MCS 방법을 모두 적용하여 비교, 평가하였다. 불확도의 요인은 ISO GUM을 엄격하게 준용하여 파악하였으며 특정일에 채취된 PM2.5 내 As 농도에 대해 두 방법의 계산 결과가 4% 미만으로 크게 다르지 않는 것으로 나타났다. 연구기간 중 채취된 총 60개의 PM2.5 시료에 대해 As 농도의 확장불확도를 역시 MCS 방법을 이용하여 산출하였는데, 연구지역에서의 As의 개별 농도값에 대한 95% 신뢰구간의 확장불확도는 대부분 10%의 범위에서 존재하는 것으로 나타났다. 확장불확도에 대한 표준불확도 요인의 기여율은 계측통계오차(62.3%), 검출효율(18.5%), 시료 채취 시 유량(12.3%), flux 변동(2.3%), 특정감마선 방출률(1.8%) 등의 순으로 크게 나타났다.

• 한국유체기계학회 논문집
• /
• 제17권4호
• /
• pp.5-10
• /
• 2014

It is possible for the nation's largest flowmeter calibration system in K-water to calibrate flow rate up to $2,700m^3/h$ and diameter 800mm. However, the calibration and measurement capability of K-water's system is not satisfied in comparison with other developed countries. In this study, we find the dominant factors related to the uncertainty of weight and time measurement for gravimetric flowmeter calibration system. As a results of improving the system, the combined standard uncertainty has been improved $1.099{\times}10^{-3}$ to $2.332{\times}10^{-4}$. So calibration and measurement capability got 0.08 percent of the relative expanded uncertainty for maximum flow rate using the coverage factor(k=2).

• 한국광학회지
• /
• 제21권2호
• /
• pp.46-52
• /
• 2010

본 논문에서는 양방향 반사율 분포함수의 이론과 제작된 측정시스템 및 측정불확도의 평가방법을 소개한다. (380~1500) nm의 분광 양방향 반사율 분포함수를 $(-75{\sim}75)^{\circ}$의 각도 범위에서 측정할 수 있는 측정시스템을 제작하였고, 상관관계가 있는 불확도 성분과 상관관계가 없는 불확도 성분으로 나누어 측정불확도를 평가하였다. 평가 결과, 제작된 양방향 반사율 분포함수 측정시스템의 상대확장불확도는 3% (k=2) 이하로 평가되었다.

• Nuclear Engineering and Technology
• /
• 제48권2호
• /
• pp.299-303
• /
• 2016

Prompt gamma activation analysis using a thermal neutron-guided beam at Japan Atomic Energy Agency JRR-3M was applied for the precise determination of Si in silicon nitride ceramic reference materials [Japan Ceramic Reference Material (JCRM) R 003]. In this study, the standard addition method coupled with internal standard was used for the nondestructive determination of Si in the sample. Cadmium was used as internal standard to obtain the linear calibration curves and to compensate for the neutron beam variability. The analytical result of determining Si in JCRM R 003 silicon nitride fine powder ceramic reference materials using prompt gamma activation analysis was in good agreement with that obtained by classical gravimetric analysis. The relative expanded measurement uncertainty (k = 2) associated with the determined value was 2.4%.

• 한국임상약학회지
• /
• 제26권1호
• /
• pp.70-76
• /
• 2016

Background: The use of the extracts from evening primrose seeds as a health functional food has been gradually increased. Therefore, the monitoring and screening process has been considerably required for its quality control. Objective: This study aimed to estimate the measurement uncertainty associated with determination of penta-o-galloyl ${\beta}$-D-glucose (PGG) in extracts from evening primrose seeds by high-performance liquid chromatography. Methods: The sources of measurement uncertainty was expressed in accordance with mathematical/statistical theories of GUM & EURACHEM Guide. The expanded uncertainty was calculated by using the relative standard uncertainty between analytical result and sources of uncertainty in measurement (sample weight, final volume, extraction volume, standard solution, matrix and instrument etc). Results: In the results of 95% confidence interval, the uncertainty in measurement was $10,253.34{\pm}1,844.50{\mu}g/kg$ (k = 2.0). Conclusion: In this study, it showed that the value of uncertainty in measurement for determination of PGG in extracts from evening primrose seeds by HPLC has about 18.0% influence on PGG contents of the analytical results. The results would be very useful for the monitoring and screening of evening primrose seeds marketed in Korea for its quality control as dietary supplement.

• 한국대기환경학회지
• /
• 제34권2호
• /
• pp.331-341
• /
• 2018

Hazardous air pollutants(HAPs) in the atmosphere are regulated as major air pollutants in Korea by the Air Pollution Control Act. In order to manage and control HAPs, accurate standards, which are traceable to the International System of Units(SI), are required. In this study, primary standard gas mixtures(PSMs) of volatile organic compounds(VOCs) which are specified as HAPs were developed at $1{\mu}mol/mol$ levels. The selected fourteen VOCs include Benzene, Toluene, Ethylbenzene, m-Xylene, Styrene, o-Xylene, Chloroform, 1,1,2-Trichloroethane, Trichloroethylene, Tetrachloroethylene, 1,1-Dichloroethane, Carbon tetrachloride, 1,3-Butadiene, and Dichloromethane. The HAPs PSMs were gravimetrically prepared in aluminum cylinders and their consistency was verified within the relative expanded uncertainty of 0.71% (k=2). Potential adsorption loss onto the internal surface of cylinders was estimated by cylinder-to-cylinder division method. No adsorption loss was observed within the uncerainty of 0.53%. The long-term stability of the HAPs PSMs was evaluated comparing with freshly prepared HAPs PSMs. The HAPs PSMs were stable for one year within the uncertainty of 0.38%. The final uncertainty of the PSMs was determined by combining the preparation uncertainty, verification uncertainty, and stability uncertainty. Finally, traceable and stable HAPs PSMs at $1{\mu}mol/mol$ levels were developed with the uncertainty of less than 0.76% in high-pressure aluminum cylinders.