The Shodex STANDARD S-Series (SL-105 Kit, SM-105 Kit, SH-75 Kit) is Polystyrene (n = 4 to 200,000) for SEC and it is easily soluble in tetrahydrofuran (THF), chloroform, toluene, and o-dichlorobenzene (ODCB).
For organic solvent SEC (GPC)
Less branched polystyrene with anionic polymerization
Chromatographic determinations of the molecular weight (MW) properties of polymers, either in organic or aqueous phase, rely on calibration with Standards of highly characterized MWs for accurate results. Expressed simply, Size Exclusion (or Gel Permeation) Chromatography enables polymer molecules of different sizes in solution to be separated from one another, such that the large molecules elute first and small molecules elute last. Since the molecular size in solution (hydrodynamic volume) is related to MW, a picture of the entire MW Distribution (MWD) may be obtained quickly and simply. This is in great contrast to the “absolute” techniques of MW determination which frequently could take half a day per sample to define a single average MW.
Polymer Standards are thus an integral part of any quantitative Size Exclusion Chromatography. These Standards need to be highly characterized by as many absolute and chromatographic techniques as possible to define the MW averages and MWD. The closer the value of the MWD is to unity, the sharper will be the polymer peak and the better the material will be for a Calibration Standard.
Note: Molecular weights (Mp, Mw/Mn) of a standard kit or each single type may vary depending on production lots. Always refer to the inspection certificate.
Molecular weights (Mp) Range*
0.5 g x 10 kinds
580 − 25,000
0.5 g x 10 kinds
1,000 − 2,500,000
0.5 g x 7 kinds
600,000 − 7,000,000