야채음료 중 비타민 C 분석에 있어서의 측정불확도 추정

Estimation of Measurement Uncertainty in Vitamin C Analysis from Vegetable and Fruit Juice

  • 발행 : 2003.12.01

초록

분석 중 소실되기 쉬운 야채음료의 비타민 C 함량을 HPLC를 이용하여 측정하였으며, 불확도인자로서 표준품의 무게, 순도, 분자량, 희석 등과 시료의 무게, 검정곡선, 회수율 및 정밀성 등이 작용하였다. 이러한 미심쩍음 정도와 더불어 계통오차와 우연오차 등 일련의 과정을 GUM(Guide to the expression of Uncertainty in Measurement)과 EURACHEM에 근거하여 수학적 처리 및 통계방법을 이용하여 측정불확도를 추정하였다. 추정방법은 각각의 인자들에 대하여 A-type또는 B-type으로 산출된 표준불확도 값을 합성하여 합성표준불확도를 산출하고, 확장불확도는 유효자유도로 산출된 포함인자를 곱하여 계산하였다. 야채와 과일이 혼합된 음료 중 비타민 C 함량은 27.53mg/100g이었으며, 포함인자(2.06)를 곱한 확장불확도는 0.63mg/100g로서 95% 신뢰도구간에서의 비타민C의 결과는 $27.53{\pm}0.63mg/100g$(95% 신뢰도 구간)과 같이 수치화하여 표현하였다. 비타민 C 분석의 경우 HPLC를 이용한 시료 분석의 회수율 및 정밀성(33%), 표준품 순도(23%), 표준용액 희석시(18%), 표준품 무게(10%), 시료 측정시(10%), 검정곡선(6%) 순으로 불확도를 추정할 수 있었다. 또한, 이를 통해서 시험원의 분석과정 중 불확도가 높게 산출된 실험과정에 대해서는 좀더 세심한 주의가 요구되며, 시료의 반복실험 시 재현성 있는 결과가 산출될 수 있도록 숙련도를 높일 필요가 있다.

This study aimed to determine the amount of vitamin C from vegetable & fruit juice by high performance liquid chromatograhy (HPLC). Components for estimation of measurement uncertainty associated with the analysis of vitamin C, such as standard weight, purity, molecular weight, dilution of standard solution, calibration curve, recovery, and precision, were importantly applied. The estimation of uncertainty obtained with systematic and random error based on the GUM (Guide to the expression of uncertainty in measurement) and EURACHEM document with mathematical calculation and statistical analysis. The components, evaluated ty either Type A or Type B methods, were combined to produce an overall value of uncertainty known as the combined standard uncertainty. An expanded uncertainty was obtained by multiplying the combined standard uncertainty with a coverage factor (k) calculated from the effective degree of freedom. The content of vitamin C from vegetable and fruit juice was 27.53 mg/100g and the expanded uncertainty by multiplying by the coverage factor (k, 2.06) was 0.63 mg/100g at a 95% confidence level. It was concluded that the main sources were, in order of recovery and precision, weight and purity of the reference material, dilution of the standard solution, and calibration curve. Careful experiments on other higher uncertainties is further needed in addition to better personal proficiency in sample analysis in terms of accuracy and precision.

키워드

참고문헌

  1. Anonymous. Guide to the Expression of Uncertainty in Measurements. International Organization for Standardization (ISO), Swizerland (1993)
  2. Anonymous. Quantifying Uncertainty in Analytical Measurements. EURACHEM, England (1995)
  3. Anonymous. Quantifying Uncertainty in Analytical Measurements 2nd. EURACHEM, England (2000)
  4. Anonymous. Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results. NIST Technical Note 1297, NIST, Korea(1993)
  5. Anonymous. Guide to the Expression of Uncertainty in Measurement. KRISS, Korea (1998)
  6. Woo, J.C. Uncertainty in measurements and analysis (I). J. Anal. Sci. Technol 13: 19-26 (2000)
  7. Woo, J.C. Uncertainty in measurements and analyses (II). J. Anal. Sci. Technol 13: 49-56 (2000)
  8. Woo, J.C. Uncertainty in measurements and analyses (III). I. Anal. Sci. Technol 13: 57-69 (2000)
  9. Woo, J.C., Suh, J.K. and Moon, D.M. Uncertainty in measurements and analyses (IV). J. Anal. Sci. Technol 13:79-87 (2000)
  10. King, B. Meeting the measurement uncertainty and traceability requirements of ISO/IEC standard 17025 in chemical analysis. Fre. J. Anal. Chem. 371: 714-720 (2001) https://doi.org/10.1007/s002160100995
  11. Aleksandrov, Y. I. and Belyakov, V. I. Error and uncertainty in the results of chemical analysis. J. Anal. Chem. 57: 94-103 (2002) https://doi.org/10.1023/A:1014089800682
  12. Dorne, J.L., Walton, K. and Renwick, A.G. Uncertainty factors for chemical risk assessment. Food Chem. Toxicol. 39: 681-696 (2001) https://doi.org/10.1016/S0278-6915(01)00005-9
  13. Shu, J.K., Woo, J.C., Moon, D.M. and Park, M.S. An error model for the evaluation of uncertainty in calibration process. Bull. Korean Chem. Soc. 22: 251-252 (2000)
  14. Yates, P.C. A simple method for illustrating uncertainty analysis. J. Chem. Edu. 78: 770 (2001) https://doi.org/10.1021/ed078p770
  15. Kim, BJ., Kim, D.H., Choi, J.O. and So, H.Y. Quantitative analysis of trace pp'-dde in corn oil by isotope dilution mass spectrometry: uncertainty evaluations. Bull. Korean Chem. Soc. 20: 910-916 (1999)
  16. Jang, G.C., Lee, U.C., Baik, S.O. and Han, S.B. Uncertainty in determination of menthol from mentholated cigarette. J. Korea Soc. Tabacco Sci. 22: 91-99 (2000)
  17. Anonymous. A Guide on Measurement Uncertainty in Chemical Analysis. Singapore Accreditation Council, Singapore (2000)
  18. Grande, B.C., Falcon, M.S.G., Comesana, M.R. and Gandara, J.S. Determination of sulfamethazine and trimethoprim in liquid feed premixes by hplc and diode array detection, with an analysis of the uncertainty of the analytical results. J. Agric. Food Chem. 49: 3145-3150 (2001) https://doi.org/10.1021/jf010071x
  19. Gardner, J.L. Uncertainty estimation in color measurement. Color Res. Application 25: 349-355 (2000) https://doi.org/10.1002/1520-6378(200010)25:5<349::AID-COL5>3.0.CO;2-N
  20. Ambrus, A. Measurement of uncertainty in pesticide residue analysis: Implications in legal limits. Italian J. Food Sci. 12: 259-278 (2000)
  21. Alder, L., Korth, w., Patey, A.L. van der Schee, H.A. and Schoeneweiss, S. Estimation of measurement uncertainty in pesticide residue analysis. J. Assoc. Off. Anal. Chem. 84: 1569-1578 (2001)
  22. Hayashi, Y. and Matsuda, R. Measurement of uncertainty and discrimination limit in purity tests of drug quality. J. Pharm. Biomed. Anal. 15: 697-708(1997) https://doi.org/10.1016/S0731-7085(96)01901-2
  23. Lee, H.S., Kim, M.S. and Choi, J.O. A study on the proficiency test of pH measurement. J. Anal. Sci. Technol. 14: 230-237 (2001)
  24. Pharmaceutical Society of Japan. Standard Method of Analysis for Hygienic Chemists. Pharm. Soc. Japan, Tokyo, Japan (2000)
  25. Lee, S.M., Yu, R.N., Rhee, S.H. and Park, K.Y. Effects of carrot on the stability of vitamin C in (green-yellow) vegetable juices. J. Korean Soc. Food Sci. Nutr. 26: 582-587 (1997)
  26. Anonymous. IUPAC commission on atomic weight and isotopic abundances. J. Pure Appl. Chem. 69: 2471-2473 (1997) https://doi.org/10.1351/pac199769122471