Syringe Care

Section Overview

• Inspection & General Tips
• Cleaning & Unclogging
• Syringe Lubrication
• Tips to Assure Accuracy & Precision
• Ensuring Syringe Sterility
• Enhancing Syringe Efficiency

Inspection & General Tips

Syringes are precision instruments. The care you take in using, handling and storing them will dictate their accuracy, reproducibility, and lifetime; also, the quality of the resulting chromatogram can be affected by a damaged syringe.

Routinely inspect the syringe for damage including hairline cracks. Discard any syringe with a potentially unsafe barrel. The needle’s tip must be free of barbs which could potentially rupture the septum and produce particles that might clog the needle, or lodge in the injection port and damage the chromatographic system.

If your syringe contains a PTFE tip, be sure to replace the plunger and tip assembly immediately if any metal is exposed. The exposed metal scrapes the glass of the syringe barrel, producing glass fragments that cut grooves in the PTFE tip. These grooves allow sample to leak past the tip.

Caustic samples or cleaning solutions that seep under the PTFE tip can destroy the sharp barb that holds the tip onto the plunger. The tip, so loosened, could slip off during sample aspiration.

Between samples, the syringe should be flushed 5-10 times its total capacity to eliminate carryover. Draw sample and expel the first several flushes to waste to avoid contamination of the sample.

Never store a syringe without first cleaning it and then wiping dry all external surfaces.

Cleaning & Unclogging

A syringe should be flushed with approximately 5-10 times its total capacity to eliminate carryover between samples. This is achieved by repeatedly drawing and expelling solvent/sample from the syringe. To avoid contaminating the sample, the first 2-3 washes should be discarded to waste.

A syringe should be flushed with approximately 5-10 times its total capacity to eliminate carryover between samples. This is achieved by repeatedly drawing and expelling solvent/sample from the syringe. To avoid contaminating the sample, the first 2-3 washes should be discarded as waste.

Appropriate solvents are those that dissolve the contaminating substances. Methanol, methylene chloride, acetone, and acetonitrile are common. For storage, the final rinsing should be with deionized water, followed by acetone.

Do not immerse the entire syringe in the solvent; this may damage the adhesives holding parts of the syringe together.

To unblock a needle, remove the plunger and fill the barrel with solvent using another syringe. Insert the plunger and push solvent through the needle.

Heating will remove semivolatile substances. Remove the plunger before heating. Fixed needle syringes can be heated to 70 °C. Removable needle syringes can be heated to 120 °C. Please refer to the syringe’s specific instructions.

A needle cleaning kit (21578) and syringe cleaning solution (20742) are available. The Hamilton syringe cleaner (20770-U) uses heat and vacuum to clean and restore performance.

Syringe Lubrication

Syringes do not require any lubricating grease. Grease may cause a variety of problems including: sample cross contamination, seizing of the plunger in the barrel or barrel damage. Minimize the use of a dry syringe; for lubrication, use an appropriate solvent that is compatible with the sample.

Tips to Assure Accuracy & Precision

Grasp the syringe only by the flange and plunger button. By doing so, variations in liquid measurement due to body heat are avoided.

Pump the plunger with the syringe needle immersed in the fluid to be transferred to expel any trapped air in the needle and syringe.

If the plunger is accidentally removed from the syringe barrel, wipe it carefully with a lint-free tissue. Reinsert the plunger into the barrel and pump deionized water or acetone through the needle and syringe. In the case of plungers with PTFE tips (like Hamilton’s Gastight syringes), re-wet the PTFE plunger tip prior to reinserting it into the barrel. Avoid touching the exposed plunger since any abrasions, scratches, or oil from one’s fingers will often interfere with proper plunger operation.

Ensuring Syringe Sterility

To prevent contamination and to ensure safety in lab environments, maintaining the sterility of syringes is essential. Syringes can remain sterile for varying periods, depending on how they are packaged and stored.

Ensure syringes are pre-sterilized and sealed by the manufacturer. Check for any tears, punctures, or damage. Store syringes in a clean, dry, and cool environment. Keep them away from direct sunlight, moisture, and temperature extremes, and use designated sterile storage areas or containers. Use glass or high-quality plastic syringes that are chemically resistant to the solvents and reagents used in chromatography.

Sterilization Methods for Reusable Syringes

Autoclaving:

Use steam under pressure to sterilize syringes. Ensure proper temperature and pressure settings, as recommended by the manufacturer.

Chemical Sterilization:

Use chemical sterilant for syringes that cannot withstand high temperatures. Follow the manufacturer's guidelines for contact time and concentration.

Dry Heat Sterilization:

Suitable for syringes that can tolerate high temperatures without moisture.

Ethylene Oxide (EtO) Sterilization:

Used for heat-sensitive syringes. Ensure proper aeration after sterilization to remove residual gas.

Enhancing Syringe Efficiency

Ensure the syringe is clean and dry before use. Filter samples using appropriate filters to remove particulates that can clog the syringe or chromatography column.

Handling Liquids:

Draw liquids slowly to avoid air bubbles and ensure accurate measurements. Use the correct technique to expel air bubbles by tapping the syringe and pushing the plunger gently.

Handling Gases:

Ensure airtight seals to prevent leaks. Use appropriate fittings and connections for gas sampling or injections.