Thermo Scientific screw caps are organised into three different performance levels to suit different experiments, analytes, and budgets. SureSTART 9 mm screw caps provide you with the performance, reproducibility, and accuracy of results you’re looking for.
Performance Level 1 screw caps are for everyday applications and are a cost-effective choice.
Performance Level 2 screw caps are for high-throughput applications, when robustness and reproducibility are key.
Performance Level 3 screw caps provide the ultimate performance and sensitivity, while maintaining the highest levels of sample security and integrity.
Thermo Scientific Advanced Vial Closure System (AVCS) caps are polypropylene caps that are compatible with all 9 mm short thread screw vials, although it is recommend that they are used with Thermo Scientific SureStop vials to get maximum benefit of the two technologies.
There is a levelling feature within the AVCS designed caps that provide optimal liquid sealing. The innovative features found on the AVCS cap also give more autosampler compatibility with less autosampler interruptions, because of misaligned cap tilting, dislodged septa or septa push through.
AVCS caps not only have the most effective seal, but they also contain significantly less leachables than bonded caps. You’ll see a noticeably cleaner spectra when you use SureStop and AVCS as an alternative to bonded caps. The AVCS caps also come with a range of different septa materials.
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/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.
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.