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Evaluation of the sealed‐tube low‐temperature combustion method for the 13 C/ 12 C and 2 H/ 1 H ratio determinations of cellulose nitrate
Author(s) -
Tao FaXiang,
Aucour A.M.,
Sheppard S. M. F.,
Liu CongQiang,
Leng XueTian,
Wang ShiLu,
Liu GuangShen,
Xu WenBir
Publication year - 2001
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.20010191115
Subject(s) - chemistry , combustion , nitrogen , cellulose , hydrogen , analytical chemistry (journal) , carbon fibers , tube (container) , nitrous oxide , radiochemistry , liquid nitrogen , isotopes of nitrogen , inorganic chemistry , chromatography , waste management , organic chemistry , materials science , composite number , engineering , composite material
Traditionally‐suggested combustion time of 1 h at 550°C) with the sealed‐tube combustion method for determining the 13 C/ 12 C ratio of cellulose nitrate or other nitrogen‐containing components could produce large negative deviation up to 1°. Three types of cellulose are used to ascertain possible causes. The presence of nitrous oxide (N 2 O) formed during combustion is most likely responsible for this deviation. Prolongation of the combustion time (at least 5 h at 550°C) and intimate contact between copper oxide and organic matter can greatly improve the analysis precision and effectively reduce this deviation to an acceptable level. Regardless of scattered carbon isotope data, hydrogen isotope data are all reproducible within 2° when this method is coupled with the high temperature uranium reduction method. Thus, care should be taken for determining carbon and nitrogen isotope compositions of nitrogen‐containing substances using the low temperature sealed‐tube combustion method.