Ciencia e Ingeniería en Alimentos y Biotecnología

URI permanente para esta comunidadhttp://repositorio.uta.edu.ec/handle/123456789/412

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2016 - 20172

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  • Miniatura
    Item type:Ítem,
    Validación del método para la determinación de vitamina C (ácido ascórbico) en alimentos por Cromatografía Líquida de Alta Eficacia (HPLC)en el laboratorio ECUACHEMLAB Cía. Ltda.
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos. Carrera de Ingeniería Bioquímica, 2017-09)
    Aguirre Arias, Sofía Lizeth
    ;
    Córdova Suárez, Manolo Alexander
    Validation of a method is an important requirement to ensure reliable and reproducible results from test laboratories. Validation was performed using the methodology described by AOAC 967.21, supplemented with the methodology (Ledezma - Gairaud, 2004), under ISO / IEC 17025. The developed method produces a linear response with a correlation coefficient r = 0.999 for each curve Calibration, LD equal to 0.0002 mg / ml and LC equal to 0.007 mg / ml. The working range comprises values from 0.007 mg / ml to 0.1448 mg / ml for the concentration of ascorbic acid ranging from 7.25 mg to 142.73 mg of vitamin C per 100 g of sample. The coefficient of variation was less than 2 percent for repeatability and reproducibility. The percentage recoverability was found in the range established for HPLC with a value equal to 99.32 percent. The limits of repeatability and reproducibility with values of 2.16 mg / 100 g and 2.61 mg / 100 g of ascorbic acid, respectively. The combined uncertainty of the method for all concentration levels employed with a value equal to +/- 0.95 and the expanded uncertainty with a value equal to +/- 1.91 expressed in units of mg of vitamin C per 100 g shows; It was used as an acceptance criterion that the value of the uncertainty is less than 30 percent of the low range resulting in the uncertainty found 26.31 percent, thus fulfilling the objective of validation.
  • Miniatura
    Item type:Ítem,
    Determinación de vitamina B2 (Riboflamina) por Cromatografía líquida de alta eficacia (HPLC) en el Laboratorio ECUACHEMLAB Cía. Ltda.
    (Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos. Carrera de Ingeniería Bioquímica, 2016-09)
    Semanate Bautista, Mario Fernando
    ;
    Córdova Suárez, Manolo Alexander
    The validation of analytical methods is an essential process that laboratories must implement to ensure that the results of analyzes are reliable and reproducible with a basis and statistical analysis. Similarly, the methodology used for validation shows a great performance in working conditions of Ecuachemlab. For the determination of Vitamin B2 (Riboflavin) using high-performance liquid chromatography (HPLC), the methodology described in the AOAC 970.65 Method modified and ISO / IEC 17025 were used. They describe the guidelines and parameters for validation of the method used to ensure the validity results. The analytical parameters determined for method validation are linearity, working range, detection and quantification limits, precision, accuracy and uncertainty. The results, for linearity show a coefficient of correlation higher than r = 0.999 for each calibration curve, LD is equal to 0.002 ug / ml and the LC is 0.08 ug / ml. The working range comprises a concentration of 0.008 mg / ml of riboflavin as a lower limit and 1,003 ug / ml of riboflavin as an upper limit. The coefficient of variation for repeatability and reproducibility is less than 3 and 5% respectively. To determine the accuracy, a Z-score within the limits for each MRC was considered. Finally it was identified a combined and expanded uncertainty for the first three levels set of +/- 0.04 and +/- 0.08 mg vitamin B2 per 100 g of sample respectively. For the last level value it was established an uncertainty value of 0.05 +/- combined and expanded uncertainty equal to +/- 0.09 mg vitamin B2 per 100 g of sample, working at a confidence interval of 95% with a coverage factor k = 2.