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A Screening method for total oxalate determination in plant material by gas chromatography
Author(s) -
Sutikno A. Irawan,
Suherman D.,
Tangendjaja B.
Publication year - 1987
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740390306
Subject(s) - chemistry , reagent , chromatography , methanol , oxalate , chloroform , hydrochloric acid , boron trifluoride , gas chromatography , organic chemistry , catalysis
Oxalates in plant material can be methylated directly to from dimethyl oxalate. After addition of water and chloroform, the volatile compoun is extracted into the organic phase and analysed quantitatively by gas chromatography. Some forms of oxalates are difficult to methylise, and this is apparent when 20% boron trifluoride‐methanol is used as the methylating reagent. The use of 7% hydrochloric acid‐methanol improved methylation, but the best result was obtained by repacing the acid catalyst with sulphuric acid and increasing the acid concentration up to 30%. Using this reagent, recovery from spiked samples was satisfactory (ranging from 92 to 105%), and precision of the method was good (Relative Standard Deviation (RSD) 1.3% at a total oxalate content of 1.95%).