Application Note ^49
Dextran is used as a blood plasma
volume expander or blood flow improver.
The dextran molar mass is crucial for the
success of the therapy.
PSS WinGPC UniChrom is a
macromolecular chromatography data
system (MCDS) that offers comprehensive
solutions for the characterization of
macromolecules with GPC/SEC/GFC,
interaction polymer chromatography
(IPC) and 2-dimensional chromatography
(2D) supporting all multi-detection
techniques. Specific e-workflows in
WinGPC guide scientists through special
tasks such as United States Pharmacopeia
(USP) and European Pharmacopoeia
(EP) recommended low-molecular-weight
(LMW) heparin calibration and analysis,
sieve curve and MW cut-off determination
or gelatin-specific calibration and
multi-area analysis.
The latest addition to the e-workflows
in WinGPC is the molecular weight
determination of dextrans. A specific
routine allows for calibration and molar
mass determination for dextran 40, 60
and 70 as stated by USP and EP. USP/
EP recommend aqueous size exclusion
chromatography (SEC), with a specific
dextran calibration to determine the
molar mass information. Specific results
for dextran samples include the weight
average molar mass (Mw) for the whole
dextran as well as for the fractions at 10
percent and 90 percent. USP additionally
requires Mn and the polydispersity
index (DI).
PSS WinGPC Software has a specific
e-workflow implemented comprising
data capture, specific dextran calibration,
data analysis and compliant reporting.
Regulated laboratories should opt for the
WinGPC UniChrom Compliance Pack
for FDA 21CFR11 support, including
audit trails and electronic signatures.
The “Dextran Monograph Calibration”
dialogue (Figure 1) uses five dextran
standards of known molecular weights
ranging from 4,000 to 250,000 Da,
Glucose (180 Da, total column volume
[Vt]) and a value for the V 0 (column voidvolume) to start the iterative non-linear
regression fit based on the concept by
Nilsson and Nilsson. As the monographs
differ slightly in their requirements,
scientists have to choose between the EP
method and the USP method. If the data
can be successfully fitted, a WinGPC
calibration file is saved and a report
is printed.
Recorded data of the verification
samples (System Suitability,
Performance) and unknown dextrans can
then be evaluated using the calibration
curve created above and a specific menu
item. WinGPC will automatically
determine three different areas for the
full dextran, 10 percent eluted mass and
90 percent eluted mass.Read the full app note at
http://tas.txp.to/1018/ANPSSMolecular Weight
Determination for
Dextran 40/60/70
According to USP/
EP Monograph
A specific e-workflow in PSS
WinGPC MCDS allows for
calibration and molar mass
determination for Dextran 40,
60 and 70 as stated by USP
a n d E P.
By Wolfgang Radke, Daniela Held,
Huub Bock and Peter Kilz
Figure 1. “Dextran Monograph Calibration” dialogue in WinGPC.http://www.pss-polymer.com