Syringe Care

When dosing fluids with higher or lower Viscosity, easily vaporisable or gases:

Gastight syringes with a seal prevent the solvent from evaporating, however the fluid mustnt be ejected quickly (forcefully) as this damages the seal on the plunger because it rubs against the glass barrel.Depending on the task at hand, we offer syringes with and without a seal.

You should also remember to use a correct syringe for the volume you want to dose:

Microsyringes are precisely manufactured. To avoid imprecision when dosing manually do not dose volumes smaller than 10% of the total capacity, (no less than 10µl with a 100µl syringe)

When Piercing the septa e.g. during GC:

To use a needle with 17 degree bevel for example, our type A, where the forces required for penetration are minimal. Please check the tip for damage, otherwise it can damage the septa and contaminate the sample with particles and/or clog the needle itself.

For special cases and for use with Headspace we offer needles type D tip, which has a closed tip (dome) and a hole on the side.

When dosing with a HPLC-valve:

Use our HPLC syringes with needle tip B. These needles are designed specifically for HPLC valves so the seal will not be damaged.

For pipetting:

We recommend needles bevel B.

If you use an autosampler:

You can use our bevel C, which we developed specifically for GC Autosamplers. With needles of a gauge 23 and 23s you can dose using MerlinVentile. Thanks to the bevel C the needle is protected from bending if the needle hits the bottom of the vial, which also prevents damage to the septa.

If you want to perform a Zero-dead-volume dosage:

Our T-Series (plunger in needle) leaves no fluid in the needle after ejection since the plunger ends at the very tip of the needle. The modular design of the T-series allows quick and easy cleaning, replacement of any damaged parts and can even be put together and repaired on the spot by you without any need for qualified technicians or costly shipping back and forth.

Make sure to choose the correct needle gauge:

Different levels of viscosity require different needles with specific inner diameter on our offer. We offer individual advice in that matter, however, a manual is also available in our catalogue and on our website.

You can prevent problems with needles:

By regular flushing, however there mustnt be any fluid left in the needle after flushing. You can dry it with vacuum by pulling the air through for example with a higher volume syringe or with a vacuum pump. Syringes with a small inner diameter of the needle are shipped with a cleaning wire. In addition a selection of cleaning wires for different diameters is available. If you work with substances which cause minor clogging, take a look at syringes with removable needles.

If you have problems with carry-over:

Perform cleaning procedures often. If some of the substance remains in the needle you should use our special coated needles.

Avoid problems with gas pockets:

If the syringe is drawn too quickly, it can lead to vaporisation of the solvent through low-pressure. High volume syringes are especially susceptible to stronger depressions. It helps if the syringe is drawn slowly or if we use a needle with a bigger inner diameter.

The autosampler cycle must be adjusted for best results.

Quick ejection moves the pockets.

It is also possible to remove the gas pockets through overfilling the syringe, turning it upside down (needle up), allowing the pockets to move upwards. Eject them.

If the plunger becomes stuck in the glass barrel:

The N-Series syringes must be flushed and dried often to prevent the plunger from getting stuck.

However, our A-Series with special seal deals with this problem much better and can also handle sticky liquids easily. The plunger goes through a seal on the top end, the movement of the plunger has been upgraded (no side loading), which ensures a longer lifetime for your syringe.

How to best clean your syringes:

Clean the syringe thoroughly, preferably in an ultrasonic bath.

Wipe the plunger with a non-fibre shedding cloth, holding it by the handle.

Flush syringe with acetone or methanol and dry with pressurised air or vacuum.

Do not completely immerse the syringe in organic solvent, as this may attack some of the materials.

Only insert plunger when the syringe is completely dry. Do not move the plunger unnecessarily while it is dry. In humid environments, store the plunger and glass barrel separately and connect only when you want to use them.

If a plunger with seal is very hard to move:

You can reduce the movement force necessary by heating or cooling. A video tutorial is available on our website.

If the needle has come off:

Remember that all glues are synthetic and have a corresponding solvent. For aggressive substances use a syringe with a removable needle. If possible, we can also repair the syringes for a small fee.