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SGE Syringe Tips
- To maximize accuracy and reproducibility, it is recommended that the minimum
volume injected from a syringe is 20% of the total syringe capacity.
- To eliminate carryover between samples, flush the syringe with solvent 15-20
times, remembering to discard the first 2-3 washes
- Achieve a 1% RSD instantly by presetting the syringe volume.
- Large volume injection syringes are ideal for temperature programmable split
injection.
- For best syringe life, ensure your syringe is rinsed 5 to 10 times in clean
solvent prior to storage.
Frequently Asked Questions
What syringe should I use?
For the best possible injection reproducibility and accuracy, the smallest
injectable volume from any syringe should generally be no less than 20% of it
total capacity, (the smallest recommended injection volume from a 10µL
syringe would be 2µL). For capillary injection, a microvolume plunger-in-needle
syringe is recommended.
The standard full scale length on a 0.5-10µL syringe is 54.1mm. The standard
scale length on a 25µL-25mL syringe is 60mm.
What is adequate washing and flushing of a syringe?
A syringe should be flushed with approximately 5-10 times its total capacity
to eliminate carryover between samples. This is achieved by drawing and expelling
the solvent/sample from the syringe several times. To avoid contaminating the
sample, the first 2-3 washes should be discarded to waste.
How do I eliminate air from the syringe and needle?
Small air bubbles can be removed by drawing the sample into the barrel and
rapidly expelling the sample while keeping the needle tip immersed in the solution.
Repeat this activity several times. Turning the syringe barrel upright while
expelling the sample may also help remove bubbles.
What technique is recommended for accurate and reproducible injection?
After removing the air bubbles, overfill the syringe. Holding it vertically
at eye level, with the needle pointing upwards, press the plunger until the
desired injection volume is reached. Draw the plunger back slightly and then
wipe the needle tip with a lint free tissue making sure that the sample is not
drawn from the needle. Inject the sample.
Are there temperature limits to consider?
SGE syringes have been designed to withstand temperatures up to 120°C.
However, rapid changes in temperature can lead to splitting the glass barrel.
Plungers should be removed for autoclaving procedures.
How should I inspect my syringe?
Syringes should be routinely checked for damage to the barrel and needle.
Look for hairline cracks in the barrel. Replace a cracked barrel with a new
syringe. Needles should also be checked for burrs and rough surfaces that may
cause tearing and excessive wear on the septum. Burrs may tear GC septa leading
to sample loss or poor peak shape.
Syringe cleaning
Under most circumstances methanol, methylene chloride, acetonitrile or acetone
is suitable for routine cleaning of a syringe. The selection of a solvent for
cleaning a syringe should be made with consideration to the contaminating material
in the syringe. Under no circumstances should the entire syringe be immersed
in solvent. The adhesive used to bond the metal flange and front needle fittings
to the glass barrel can be damaged. Clean the outside surfaces of the syringe
by simply wiping with a cleaning material.
After use and before storing, always thoroughly rinse the syringe with solvent.
Ensure that the syringe is dried so that there is no residual solvent in the
barrel.
Plunger care
Never force the plunger. Replacement plungers for standard syringes are not
available. Plungers fitted to these syringes are individually fitted to the
barrels to achieve a perfect seal. This means that plungers are not interchangeable.
The ease with which a plunger slides in a glass barrel in not an indication
of the quality of seal between the glass barrel and metal plunger. A perfectly
sealing plunger may appear to be loose in the barrel.
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