Waters Envirogel GPC Cleanup Column User Manual
[ Care and Use ManUal ]
Waters envirogel gPC CleanuP Column
The Waters GPC Cleanup System uses two Envirogel™ GPC Cleanup
Columns to perform routine cleanup of environmental samples
as specified by EPA Method 3640A, GPC Cleanup. T he columns,
19 x 150 mm and 19 x 300 mm, are connected in series.
A 4.6 x 30 mm Guard Column is available for customers interested in
using a guard column in front of the column set.
The Envirogel columns:
• are packed with high-performance, fully-porous, highly
cross-linked, styrene divinylbenzene copolymer particles.
• contain 100 Å pore size material, with a nominal particle size
of 15 μm.
• are shipped with methylene chloride as the mobile phase.
• the same three columns packed in 50/50 ethyl acetate/
cyclohexane are also available.
Contents
I. Installing the Columns
a. Connecting the Column
b. Equilibrating the Columns
II. Calibrating the Columns
a. Preparing the Calibration Solution
b. Procedure
c. Injecting the Calibration Solution
d. Calculating Peak Resolution
e. Requirements
III. Column Care and Use Guidelines
IV. Column Storage
a. Short-term
b. Long-term
V. Care and Maintenance
VI. Ordering Information
Waters Envirogel GPC Cleanup Column
VII. Warrenty/Service Information
[ Care and Use ManUal ]
i. installing tHe Columns
When installing the Waters GPC Cleanup System for the first time,
refer to Chapter 2 “Preparing the System” for instructions on
connecting the fluid lines and purging the system. This section
describes:
• Connecting columns to the system
• Equilibrating the columns
Do not connect the columns to the injector or detector until the GPC
Cleanup System is purged with methylene chloride. Refer to the
Waters GPC Cleanup System Operator’s Guide for more information.
a. Connecting Columns
To connect the columns to the system:
1. Remove the end plugs from the columns and save them for use
when storing the columns.
2. Place a ring stand or other column mounting device between the
injector and detector. Mount the columns so that sample flows
through the columns as shown in Figure 1.
3. Connect the tubing from the injector outlet to the column inlet
on the small column. Using a wrench, tighten the connection
1/4 to 1/2 turn beyond hand-tight. Do not over-tighten the
fittings; over-tightening damages the connection.
4. Connect the outlet of the smaller column to the inlet of the
larger column, using the 0.009-inch i.d., U-shaped, and column
joining tube.
5. Connect the column outlet tubing (supplied separately with
the detector) to the outlet of the larger column. Place a waste
collection flask at the outlet tubing from the last column.
6. Set the pump flow rate to 1 mL/min, and collect column effluent
for 1 minute.
7. Increase the flow rate 1 mL/min, and collect column effluent for
1 minute. Repeat until the flow rate is 5 mL/min.
8. Allow solvent to flow at 5 mL/min, until approximately 100 mL
of solvent is collected.
9. Set the pump flow rate to 0.0 mL/min. Allow the system pres
sureto return to 0 psi (approximately 30 seconds).
10. Connect the column outlet tubing to the sample inlet connection
on the detector.
Figure 1. Column Installation.
Waters Envirogel GPC Cleanup Column
b. Equilibrating the Columns
To equilibrate the columns:
1. Resume flow as in steps 6 and 7 above, until the flow rate is
5 mL/min.
2. Adjust the absorbance level to zero on the detector.
3. Monitor the UV absorbance on the detector to ensure that the
column is fully equilibrated. At a flow rate of 5 mL/min, full
column equilibration can take up to 20 minutes.
During this time you should observe no large fluctuations in pump
pressure (as indicated by the pump pressure transducer). Typical
pump pressures are approximately 200 psi at flow rates of 5 mL/min.
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[ Care and Use ManUal ]
4. Continue the flow until a stable absorbance reading is obtained.
The columns are equilibrated when the change in the absorbance
reading is ≤ 0.002 AU from zero after 500 mL of solvent passes
through the column.
5. Read just the absorbance level to zero, if necessary
ii. CaliBrating tHe Columns
The Envirogel GPC Cleanup columns are calibrated using a
calibration solution.
Calibrating the columns involves:
• Preparing the calibration solution
• Injecting the calibration solution
• Calculating peak resolution
If you are using an injector with a 5 mL sample loop, use the calibra-
tion method listed in the EPA method.
If you are using the Waters GPC Cleanup System, use the calibration
method described in this section.
Since the Waters GPC Cleanup System performs 2 mL sample injec-
tions, you must use a calibration solution that is 2.5 times more
concentrated than the calibration solution listed in the EPA method.
A 2 mL injection of the concentrated calibration solution achieves
mass loading equal to a 5 mL injection of the EPA method calibration
solution.
a. Preparing the Calibration Solution
Mix the calibration compounds into low acid methylene chloride (pesticide quality or equivalent). Refer to the Waters GPC Cleanup System
Operator’s Guide, Chapter 2 “Preparing the System” for the procedure
to determine the acid level of methylene chloride.
One liter of calibration solution requires the following quantities of
compounds:
Compound mg/L
Corn oil 62,500
Bis(2-ethylhexyl)phthalate 2,500
Methoxychlor 500
Perylene 50
Sulfur 200
Reduce the quantities for smaller volumes of solution.
b. Procedure
To prepare the calibration solution:
1. Weigh the Corn oil into a beaker. Since the sulfur is more soluble
in warm com oil than methylene chloride, add the sulfur to the
corn oil. Warm the mixture until the sulfur dissolves.
2. Add the remaining compounds listed in the table above to a
volumetric flask.
3. Add the warm corn oil-sulfur mixture to the volumetric flask.
4. Add methylene chloride to bring the volume of solution to one
liter.
5. Store the calibration solution away from light, at 4 ˚C, in an
®
amber bottle with a Teflon
stored up to 6 months. After storage, allow the solution to stand
at room temperature until components redissolve.
A small amount of sulfur may precipitate from the solution when the
methylene chloride is added or after the solution is stored. Remove
this precipitate by filtering the calibration solution through a GHP
®
Acrodisc
0.45 μm filter before injection.
lined screw-cap. The solution can be
Waters Envirogel GPC Cleanup Column
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