Snap Caps

• Redesign of locking tabs provides easier application and removal of caps
• Enlarged open area allows for needle penetration across the entire vial opening
• Textured outer surface for easier gripping and improved detection by autosamplers with optical vial sensors
• Fully compatible with all Snap-It vials
• Snap-It caps are easy to apply and remove
• Pre-assembled caps and septa are convenient and minimize contamination from handling
• Snap-It caps eliminate the need for crimping or de-capping tools
• Polyethylene caps are chemically inert and suitable for most chromatography applications
• Closures are shipped in sealed polybags to prevent contamination during transport
• Integral Molded Polyethylene cap is an economical choice for routine HPLC applications, but with low sealing property and zero resealing capacity

PTFE/Natural Red Rubber

PTFE/Natural Red Rubber are moderately priced seals for GC and HPLC with good chemical properties. They are ideal for multiple injections due to high resealability, but not as easy to penetrate as PTFE/Synthetic Red Rubber.

PTFE/Synthetic Red Rubber Septa

PTFE/Synthetic Red Rubber septa are an economical choice for general GC and HPLC applications. Used primarily for routine analysis in gas chromatography with FID, TCD and FPD detectors or HPLC with UV/Vis or RI detectors, PTFE/Synthetic Red Rubber septa offer good resealability and excellent chemical inertness before puncture. The low durometer of red rubber allows for easy needle penetration even with thin bore GC needles. PTFE/Red Rubber septa are not recommended for multiple injections with long run times or retention of samples for further analysis after initial puncture.

PTFE/Silicone Septa

PTFE/Silicone is the most versatile septum material offered in various formulations to address specific applications requirements. Extractables from PTFE/Silicone septa are generally at lower levels compared to other resealable materials. PTFE/Silicone septa are formulated for different hardness (durometer) meeting requirements of various needle types. Formulations offering highly consistent performance, lowest background/blank value, and good chemical compatibility, effective sealing/resealing and low penetration force make PTFE/Silicone septa suitable for all types of chromatographic applications. A thin film of PTFE is laminated to the side of the septum that faces the sample to limit exposure of the elastomer to the solvent. PTFE/Silicone septa are ideal for use in most HPLC and GC applications where resealability and purity are critical.

Pre-slit PTFE/Silicone Septa

Pre-slit septa are offered in many of the same formulations as for non-slit PTFE/silicone septa and shares most of the physical and chemical characteristics. The septum is provided with a thin 0.005” PTFE layer laminated to highly pure silicone, and slit through the center for easier needle penetration and to release the vacuum that forms when a large volume of sample is withdrawn from a vial. This septum provides chromatographic characteristics similar to that of a septum without a slit, except that the ability to withstand exposure to aggressive solvents is slightly lessened. Pre-slit septa are highly recommended for Shimadzu, Hitachi, and other autosamplers with thin gauge needles.

PTFE/Silicone/PTFE Septa

A layer of inert PTFE film is laminated to each side of high-purity, medium durometer silicone to form a septum that is resistant to coring, but still maintains good resealing characteristics. PTFE/Silicone/PTFE septa are recommended for the most critical applications such as ultratrace analysis, where there is a longer time between injections. PTFE/Silicone/PTFE septa provide superior performance with any autosampler employing a large diameter, blunt-tip needle. PTFE/Silicone/PTFE septa can have benefits when working with solvents that tend to attack silicone by protecting both sides of the elastomer.

PTFE Disk Septa

A solid disk of 0.010” thick pure PTFE offers superior chemical inertness against the most aggressive solvents. The thin membrane allows for penetration by most normal gauge metal HPLC needles. PTFE septa are not resealable and should not be used with highly volatile solvents, short cycle times or multiple injection methods. PTFE septa are rarely used for GC applications.

Polyethylene Septa and Integral Molded Closures

Chemically resistant polyethylene septa are usually molded into single-piece caps. The surface for needle penetration is 0.01" thick, allowing for use with most HPLC autosamplers. Polyethylene septa are not resealable and are intended for single injection use with aqueous based sample mixtures.

• Thermo Scientific Sample Handling Catalogue

  Contains details on Thermo Scientific's sample handling products

• SAMPLE HANDLING TECHNICAL BROCHURE

  Contains full technical information on Thermo Scientific's sample handling products