Selection Guide

We carry the popular and high-quality Hamilton, SGE and VICI® Precision Sampling analytical gas and liquid syringes and accessories. The selection of brands gives you choices based on the product offering, application relevance, instrument compatibility, and personal preference. We continually work with our customers, suppliers, and instrument manufacturers to make sure our syringe line stays up-to-date. As with all of our products, they are backed by Sigma-Aldrich’s commitment to innovation, quality, and service.

The right choice of syringe is vital to ensure proper fit and operation within the instrument, accurate and precise injections, and long functional lifetime.

Structurally, syringes must ensure a tight and secure fit in the injection port and withstand repeated injection cycles without bending or breaking. Compositionally, they must be able to withstand chemical and mechanical forces within a defined range. Chemically, they must be inert and not introduce extraneous, interfering compounds into the sample. Syringes also must deliver accurate and precise volumes with no dead volume or carryover between injections.

Syringe Selection

Termination Choices

The termination is the interface, or connection, between the syringe barrel and the needle. The choice depends on the application. Each manufacturer has its own specification nomenclature.

Fixed (cemented) – Economical, reproducible injections, for autosamplers, one syringe-one method, do not heat above 50 °C

Removable needle – One syringe-many methods, simplicity of fi xed needle, but needle can be replaced if damaged or clogged, do not heat above 115 °C

Knurled hub – Creates a leak-tight seal that can be retightened to compensate for wear

Luer tip – Easy, fast needle replacement, syringe fi lter or pump priming, Luer tip is ground glass suitable for mounting chromatographic or PTFE needles, syringes can be autoclaved (without plunger or needle)

Luer-Lok – Security of a locked needle, syringe fi lter or pump priming, PTFE, male Luer taper with nickel-plated brass locking hub for use with KEL-F® or metal hub needles and universal connectors

Syringe-Valves – Syringe with On-Off valves, head space applications, collect and store volatile samples, examples are SampleLock (Hamilton) or Pressure-Lok (VICI).

Hamilton Termination Nomenclature:
N – Fixed needle, RN – Removable needle, LT – Luer tip, KH – Knurled hub, TLL – PTFE Luer-Lok, WG – Plunger guides which prevent bending the syringe, CH – Chaney adapter, SL – SampleLock

SGE Termination Nomenclature:
F – Fixed needle provides reproducible injects at an economical price, R – Removable needle, LL – Luer-Lok, LT – Luer tip, B – Plunger-in-Needle

Needle Point Styles

Standard needles are most often point style 2 (sharp point) or 3 (blunt point). For HPLC injections and sample pipetting, the blunt-tip style 3 is preferred. The blunt tip has chamfered and polished edges that eliminate damage to the valve’s rotor seal and stator face. This style can also be used for pipetting liquids.

For manual GC injections, a beveled tip, like style 2 is preferred for optimum septum penetration and to prevent septum coring. Also, Hamilton point style AS and SGE cone-tip needles are specially designed for this application. When using an autosampler, consult the instrument manual for the preferred point style.

In syringes with point style 5, conical with side port, liquid samples can be filled and dispensed through the hole in the side. Septum damage is minimized by the solid domed tip.

Needle Gauges

Gauge is the thickness of the needle. The gauge required depends on the injector. For example, in HPLC applications, Waters instruments use a 25 gauge needle, while Rheodyne, Valco, Altex and SSI valves use 22 gauge.

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