Factors affecting the reliability and precision of the spectroscopic determination of vitamin A
Autor: | H. W. Rawlings, G. H. Wait |
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Rok vydání: | 1946 |
Předmět: | |
Zdroj: | Oil & Soap. 23:83-87 |
ISSN: | 1558-9331 0003-021X |
DOI: | 10.1007/bf02544153 |
Popis: | By means of simple statistical methods the effects of technique, laboratory equipment, solvents, temperature, and instruments on the precision and accuracy of the determination of the extinction coefficient at 328 mµ of fish liver oils are outlined. Methyl, ethyl, propyl and butyl alcohols give successively lower E-values. As the temperature increases, Beckman spectrophotometers tend to give lower values. The cells used to hold the solutions to be measured need to be individually checked. No suitable standards for spectrophotometers are yet available, but potassium nitrate, potassium chromate, and Bureau of Standard glasses are useful. By careful observance of all the variations discussed the determination of the E-value may be made with considerable precision; the value of σ, the standard deviation, is 0.22%. |
Databáze: | OpenAIRE |
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