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Quantitative determination of castor oil in edible and heat‐abused oils by 13 C nuclear magnetic resonance spectroscopy
Author(s) -
Husain Sajid,
Kifayatullah M.,
Sastry G. S. R.,
Raju N. Prasada
Publication year - 1993
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02564236
Subject(s) - castor oil , ricinoleic acid , spectroscopy , nuclear magnetic resonance spectroscopy , chemistry , edible oil , materials science , analytical chemistry (journal) , nuclear magnetic resonance , nuclear chemistry , chromatography , organic chemistry , food science , physics , quantum mechanics
Application of 13 C nuclear magnetic resonance (NMR) spectroscopy for detection of castor oil (CO) in various edible oils, such as coconut oil, palm oil, groundnut oil and mustard oil, is described. Characteristic signals observed at δ 132.4, δ 125.6, δ 71.3, δ 36.8 and δ 35.4 ppm, due to C10, C9, C12, C13 and C11 carbons of ricinoleic acid (RA) in CO, were selected for distinguishing it from edible oils. Quantitative 13 C NMR spectra of oils were recorded in CDCl 3 with a gated decoupling technique. The minimum detection limits for qualitative and quantitative analyses were 2.0 and 3.0%, respectively. The proposed method is simple, nondestructive and requires no sample pretreatment. Its application to heat‐abused oils has also been demonstrated successfully without any of the interferences observed in most other methods.