Caps for Chromatography Vials

Our closures for autosampler vials are packed in clear screw-top PET bottles for an easy and contamination free handling in the laboratory.

All caps undergo a quality check upon arrival from production.

Available cap types:

Crimp caps with centre hole, aluminium, 11 mm (ND11)
Snap caps with centre hole, polyethylene, 11 mm (ND11)
Screw caps with centre hole, glass-fibre enforced polyamide, 9-425 (ND9)
Screw caps with centre hole, polypropylene, 8-425 (ND8), 9 mm (ND9), 10-425 (ND10)

The available septum material is described in the taps below:

ms-Pure septum: non-pigmented silicone/PTFE septum

With the increasing sensitivity of the analytical instruments, extractable substances from the septum may contaminate the sample. The ms-Pure silicone/PTFE septum is produced from a natural non-pigmented silicone/PTFE. Tests show that it is 60 % cleaner than „standard“ silicone/PTFE septums on the market.

non-pigmented silicone of highest quality
low bleeding
resists coring
excellent re-seal ability
intended for multiple injections
low compression set for storage reliability

Pigmented silicone/PTFE septum

In the days when septum and caps were assembled by hand in the laboratory, it helped when the PTFE side of the septum was easily identified. Therefore the silicone and PTFE was pigmented in different colours. With the increasing sensibility of the analytical instruments, the pigmentation may interfere with the analysis.

Natural rubber/PTFE septum

The natural rubber/PTFE septum was established as standard septum in the days when silicone was much more expensive than today.

Butyl rubber/PTFE septum

Butyl is a synthetic caoutchouc. Butyl is temperature resistant from -40° C to 120° C.

Septa suitable for PFAS testing

Classic chromatography septa have a PTFE coating on the side facing the sample. However, the PTFE would contaminate the sample in the PFAS analysis. Polypropylene or Polyimide is used instead of PTFE. Butyl caps are also available.

Another option are KapOni-Pure caps (ND9) with a funnel instead of a septum. The funnel is made of inert, plasticiser-free polypropylene, which can be used in a wide temperature range from -0 °C to 100 °C. The funnel guides the syringe needle through the thin membrane of the injection site. Due to its shape, the funnel prevents evaporation of the sample even after multiple injections.

ZeroSept^® Air - phthalate-free septum

The ZeroSept^® Air septum gains its excellent sealing qualities from an air cushion trapped between two layers of high-purity PTFE foil which makes it also ideal for multiple injections.

When using a silicone or rubber septum, the needle piercing the septum will always carry some septum material into the sample which may lead to interfering peaks in the chromatogram. The ZeroSept^® Air septum eliminates the risk of interfering peaks through coring.

Tests proofed that the ZeroSept® Air septum also shows adequate sealing qualities over a period of 24 hours when used with multiple injections.

ZeroSept^® with O-ring and aluminium- / or PTFE foil

An O-ring made from fluoroplastic and with the same thickness as a common septum assures that the cap rests optimally on the vial head rim. In addition the crimping tool has not to be completely reset due to this place holder.

ZeroSept^® ALUmono-O
Phthalate free septum consisting of an O-ring made from fluoroplastic and a thin aluminium foil.

ZeroSept^® PTFEmono-O
Septum consisting of an O-ring made from fluoroplastic and a thin PTFE foil.

ZeroSept^® PTFEmono
Septum consisting of thin PTFE foil.