The comparison of titrimetrical methods for determination of ascorbic acid in vegetables | Titrimetrisko metožu salīdzinājums askorbīnskābes satura noteikšanai dārzeņos
2014
Duma, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dubova, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Zeipina, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the research was to evaluate and compare the suitability of different volumetric methods for determination of ascorbic acid in onions and lettuce. The content of ascorbic acid was determined in three varieties of onions and lettuce using two titrimetric methods – titration with 2.6-dichloroindophenol in acidic solution or iodometrically. The obtained results show significant differences depending on a titrimetrical method. The content of ascorbic acid was determined from 14.78 till 25.06 mg 100gE-1 in onions or on average 10.47 mg 100 gE-1 in lettuce using 2.6-dichloroindophenol as titrant. This method is not adaptable for coloured analyzing solutions. The results of the research show that the determined content of ascorbic acid in analyzed samples was by 1.5 to 2 times higher using the standard solution of iodine than the previous method. It allows making the conclusion that by means of this titrimetric method not only the content of ascorbic acid but also the content of other organic acids was determined.
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