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Titolo:
REPORT ON THE COOPERATIVE DETERMINATION O F MOLECULAR-WEIGHT AVERAGESOF POLYMERS BY SIZE-EXCLUSION CHROMATOGRAPHY .5. DEPENDENCE OF MOLECULAR-WEIGHT AVERAGES ON DETECTORS AND MOBILE PHASES
Autore:
MORI S; TAKAYAMA S; GOTO Y; NAGATA M; KINUGAWA A; HOUSAKI T; YABE M; TAKADA K; SUGIMOTO T; SHIMIZU M; NAGASHIMA I; HASEGAWA A; SENBA T; OOSHIMA N; MAEKAWA T; SUGITANI H; OOZEKI H; NAKAHASHI K; HIBI K; OOTANI H; NAKAMURA S; SUGIURA K; UMEDA Y; KATSUNO Y; TAGUCHI M;
Indirizzi:
JAPAN SOC ANALYT CHEM,RES COMM POLYMER ANAL,SECT SPECIAL STUDY SEC,SHINAGAWA KU TOKYO 141 JAPAN
Titolo Testata:
Bunseki Kagaku
fascicolo: 1, volume: 46, anno: 1997,
pagine: 81 - 86
SICI:
0525-1931(1997)46:1<81:ROTCDO>2.0.ZU;2-1
Fonte:
ISI
Lingua:
JPN
Keywords:
SIZE EXCLUSION CHROMATOGRAPHY; ROUND ROBIN TEST; POLYSTYRENE; POLY(METHYL METHACRYLATE); DEPENDENCE OF MOLECULAR-WEIGHT AVERAGES ON DETECTORS AND MOBILE PHASES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
5
Recensione:
Indirizzi per estratti:
Citazione:
S. Mori et al., "REPORT ON THE COOPERATIVE DETERMINATION O F MOLECULAR-WEIGHT AVERAGESOF POLYMERS BY SIZE-EXCLUSION CHROMATOGRAPHY .5. DEPENDENCE OF MOLECULAR-WEIGHT AVERAGES ON DETECTORS AND MOBILE PHASES", Bunseki Kagaku, 46(1), 1997, pp. 81-86

Abstract

The effects of the differences in detectors and mobile phases on the calculated molecular-weight averages are discussed based on the data obtained from 1st and 2nd round-robin tests. Although the weight-average molecular weights (M(w)) of polystyrene (PS) samples remained unchanged with the detectors, the Dumber-average molecular weights (M(n)) obtained with an ultraviolet absorption detector (UV) were 74 similar to88% of those with a differential refractometer (RI). The fractions ata lower molecular weight range of the differential molecular-weight distributions, calculated using UV chromatograms, were higher than those based on RI chromatograms, which caused the M(n) obtained by a UV detector to have smaller values than those by an RI detector. Peak broadening due to the cell structure or the difference in the molecular-weight dependence of the response coefficients of UV and RI detectors were negative as the main reason. The most probable assumption was that the end-structure of the PS samples affected the increase in the UV absorption. When a comparison of the M(n) values between laboratories is required, the type of detector for size-exclusion chromatography must be the same. The values of M(w) and M(w) for poly(methyl methacrylate), obtained with chloroform mobile phase, were 5 similar to 25% higher than those with the tetrahydrofuran mobile phase. PS standards were used for the calibration; in this case, the change in the values of M(n)and M(w) for other types of polymers than PS using different mobile phases had to be taken into account.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/09/20 alle ore 11:17:21