ISBN:
9789264069848
Language:
English
Pages:
Online-Ressource (9 p.)
Series Statement:
OECD Guidelines for the Testing of Chemicals, Section 1
Parallel Title:
Parallelausg. Essai n 118; Détermination de la masse moléculaire moyenne en nombre et de la distribution des masses moléculaires des polymères par chromatographie sur gel perméable
Parallel Title:
Parallelausg. Essai n 118: Détermination de la masse moléculaire moyenne en nombre et de la distribution des masses moléculaires des polymères par chromatographie sur gel perméable
Keywords:
Environment
Abstract:
This Test guideline describes the Gel Permeation Chromatography (GPC). This method permits to determine the molecular weight distribution and the average molecular weights (Mn, Mw). GPC is a special type of liquid chromatography in which the sample is separated according to the hydrodynamic volumes of the individual constituents.According to their size, the eluted molecules can or not penetrate in the porous material (typically an organic gel) of which the columns are filled. Thus, the smallest molecules are retained whereas largest elute more quickly. At exit of column, detectors (generally by differential refractometry) provide the refractive index or UV-absorption and yield a simple distribution curve. However, to attribute actual molecular weight values to the curve, it is necessary to calibrate the column by passing down polymers of known molecular weight and, ideally, of broadly similar structure, e.g. various polystyrene standards. For each sample analyzed, two independent experiments must be undertaken. They have to be analysed individually. Mn, Mw, Mw/Mn must be provided for every measurement.
DOI:
10.1787/9789264069848-en
Permalink
