GPC Sample Preparation

 

Materials

0.45 mm PTFE (teflon) filter

5 mL glass syringe

18 G needles

1 mL, 5 mL glass GPC vials

20 mL scintillation vials

Chloroform - HPLC grade

Disposable nitrile gloves

 

 

Safety

1.  Chloroform is a very volatile solvent.  Its risk codes are given as “Harmful” and “Dangerous.”  It is also a known carcinogen in animals.  

·       The Chemical Toxicity and Risk Information as well as the glove recommendations for Heavy Exposure and Intermittent Exposure are included with the protocols. 

·       In this protocol, you will be handling very small volumes of chloroform.  Single (or double) disposable nitrile gloves are appropriate. Wear disposable nitrile gloves at all times.

·       Do NOT breathe the vapors.  ALL work (measuring, mixing, filtering, cleaning, etc.) MUST be conducted in the hood. 

·       Wear a lab coat with long sleeves to protect against splashes on your arms.

·       If you spill any chloroform or chloroform mixture on your hands, immediately remove your gloves and wash your hands.  If you spill chloroform on another part of your body, wash that area immediately.

2.     Wear safety glasses at all times.

 

 

Procedure

NOTE:  Chloroform will dissolve most plastics, so everything that contacts chloroform must be glass.

ALL STEPS MUST BE CONDUCTED IN A CHEMICAL FUME HOOD.

1.     Check if polymer sample is prepared.  If not, prepare polymer samples to be tested.

·       Target concentration is 50 mg-polymer/mL-solvent.

·       A minimum of 1 mL of polymer solution must be prepared.

·       Prepare samples in 5 mL GPC vials or 20 mL scintillation vials.

·       The polymer may need up to 1 hr to dissolve.  Do not proceed to Step 3 until polymer is completely dissolved.

2.     Label 1 mL GPC vials.

 

STEPS 3. - 7. NEED TO BE REPEATED FOR EACH SAMPLE THAT IS TO BE RUN ON THE GPC.

3.     Filter the polymer solution.  Small solids and particles may clog the GPC resulting in expensive repairs.  EVERY SAMPLE THAT IS RUN ON THE GPC MUST BE FILTERED.

·       Screw needle (with cover) on glass syringe.  Remove cover.

·       Draw up the polymer solution through the needle into the glass syringe.  Draw up an additional 1-2 mL air so that the syringe contains both polymer solution and air.

·       Replace cover on needle.  Remove the needle carefully.  Discard needle in sharps container.

·       Hold the syringe upright so that the air is at the port of the syringe.  Screw a PTFE filter on the end of the glass syringe. 

·       Turn the needle upside down so that the polymer solution is at the port of the syringe.  Empty syringe of contents through the filter into a clean 1 mL GPC vial.  You will need to push the “extra” air through the filter to clear all the polymer solution of the filter.

·       Cap the GPC vial immediately.

·       Dispose of the PTFE filter.

4.     Clean the glass syringe.

·       Screw clean needle (with cover) on glass syringe.  Remove cover.

·       Draw up 1-2 mL chloroform through the needle into the glass syringe.  Draw up an additional 1-2 mL air so that the syringe contains both chloroform and air.

·       Replace cover on needle.  Remove the needle carefully.  Save the needle.

·       Rinse syringe by swishing chloroform around by gently rolling or rocking syringe.  Do NOT shake syringe.

·       Squirt chloroform out into waste chloroform container.

5.     Repeat Step 4. two more times using the same needle.

6.     Dispose of needle in sharps container.

7.     Remove plunger from syringe base and allow to air dry for 1-2 min.

8.     Repeat Steps 3. - 7. for each sample.

9.     Load glass vials in GPC carousel tray for analysis.