Development of a reference material for L-ascorbic acid in fruits and vegetables

• Author(s): Valente, A. ; Sanches-Silva, A. ; Albuquerque, T.G. ; Costa, H.S.
• Date: 2011
• Persistent ID: http://hdl.handle.net/10400.18/414
• Origin: Repositório Científico do Instituto Nacional de Saúde
• Subject(s): Composição dos Alimentos
• Document Type: Conference Object
• Language: English

Description

INTRODUCTION: Ascorbic acid (AA) is a water soluble vitamin that plays a determinant role in the defense against cellular damage through its antioxidant activity. Fresh fruits and vegetables are the main natural sources of AA. Economic, rapid, accurate and sensitive methods for laboratory analysis are needed to improve the quality of analytical data. Regular use of a reference material and participation in a proficiency testing schemes are helpful to evaluate the performance of laboratories as well as useful for the quality control of analytical procedures. AIM: The aim of the study was to develop and validate a high-performance liquid chromatography method and produce a reference material to be used as a quality control material in routine laboratory analysis. METHODS: The AA chromatographic separation was performed with a SynergiTM Hydro-RP column and UV detection at 246 nm. Validation procedure was performed according to Food and Drug Administration or International Conference on Harmonization guidelines. Homogeneity study was performed by the analysis of 20 random samples selected from two different batches. Samples stability was tested during one year at two temperatures (+4 ºC and -80 ºC) in different periods of time. RESULTS: The method was linear over the range of 1-100 μg/ml with a LOD of 0.035 μg/ml and a LOQ of 0.090 μg/ml. The within-day and between-day precision were 0.58% and 3.67%, respectively. The overall recovery values at three spiking levels (20, 60 and 100 μg/ml) were 96.7%, 96.6% and 97.3%, respectively. In the homogeneity study, no significant differences were obtained between samples from the two batches. The short- and long-term stability studies showed that orange juice samples can be kept at -80 ºC for at least 12 months after initial treatment with a stabilization solution. CONCLUSION: A full validation of a highly sensitive, rapid, precise and accurate HPLC method was performed for laboratory routine use. This method is an excellent choice for quantification of AA in foods and to generate high quality analytical data. The homogeneity and stability studies of the produced in-house reference material showed that this product is suitable for use in quality control of AA laboratory analysis.