Septum material: the key to a good analysis
The choice of the right septum material directly affects the reliability of your analysis. A septum that is too hard damages needles; one that is too soft causes coring; a high-bleed septum causes interference in the GC/MS chromatogram. Brown supplies six septum variants:
| Septum | Temperature | Application |
|---|
| Rubber/ETFE | up to 120°C | Routine analysis, economical |
| Silicone/PTFE | up to 200°C | Excellent resealability, multiple injections |
| PTFE/Silicone/PTFE | up to 200°C | Reduces coring in trace analysis |
| Butyl/PTFE | up to 140°C | Long-term sample storage |
| Ultra Clean Silicone/PTFE | up to 200°C | GC/MS, ultra-low bleed, conditioned |
| Silicone/PTFE pre-cut | up to 200°C | Pre-slit, easy needle penetration |
Ultra Clean septa are specially conditioned to remove volatile compounds such as siloxanes. This eliminates interfering peaks in GC/MS chromatograms originating from the septum itself.
Pre-cut septa (single slit, cross slit or star slit) are pre-slit so the needle penetrates the septum easily. This reduces resistance during injection and extends the life of the needle.
Crimp seals 8 mm
The 8 mm aluminium crimp seals are intended for autosampler vials with an 8 mm crimp neck, such as the limited volume vials for Agilent and the standard vials for Perkin-Elmer, SGE and Unicam.
OEM references: 03300806 (Perkin-Elmer AS2000B/AS100/300/8300)
Standard 8 mm crimp seals with pre-assembled septum
Available in silver, red, blue, gold and green. Per 100 pieces.
| Cat.nr. (zilver) | Septum |
|---|
| 151213 | Rubber/ETFE |
| 151256 | Silicone/PTFE |
| 151257 | PTFE/Silicone/PTFE |
| 151259 | Butyl/PTFE |
Coloured versions: suffix R (red), B (blue), Y (gold), G (green). For example: 151256R = Silicone/PTFE red.
Ultra Clean 8 mm crimp seals (GC/MS)
| Cat. no. | Colour | Septum |
|---|
| 157400 | Silver | Ultra Clean Silicone/PTFE |
| 157401 | Red | Ultra Clean Silicone/PTFE |
| 157402 | Blue | Ultra Clean Silicone/PTFE |
| 157403 | Gold | Ultra Clean Silicone/PTFE |
| 157404 | Green | Ultra Clean Silicone/PTFE |
Pre-cut 8 mm crimp seals
All septa are pre-slit and pre-assembled. Per 100 pieces, in 5 colours (silver/red/blue/gold/green).
| Cat.nr. (zilver) | Septum |
|---|
| 156300 | Silicone/PTFE single slit |
| 156305 | Silicone/PTFE cross slit |
| 156310 | Silicone/PTFE star slit |
Crimp seals 11 mm
The 11 mm aluminium crimp seals are the most widely used size for standard and wide opening 2.0 ml autosampler vials (12×32 mm). The large hole in the 11 mm seal reduces the risk of bent needles.
OEM references: 5181-1210 / 5182-0552 / 5181-1211 (Agilent), N930-6015 (Perkin-Elmer)
Compatible with: Agilent 7693/7683/7673, Perkin-Elmer INTEGRAL 4000/AUTOSYSTEM/XL/CLARUS, Shimadzu SIL series, Thermo, Varian, Waters.
Standard 11 mm crimp seals with pre-assembled septum
Available in silver, red, blue, gold and green. Per 100 pieces.
| Cat.nr. (zilver) | Septum |
|---|
| 151216 | Rubber/ETFE |
| 151266 | Silicone/PTFE |
| 151267 | PTFE/Silicone/PTFE |
| 151269 | Butyl/PTFE |
Coloured versions: suffix R (red), B (blue), Y (gold), G (green).
Ultra Clean 11 mm crimp seals (GC/MS)
| Cat. no. | Colour | Septum |
|---|
| 157425 | Silver | Ultra Clean Silicone/PTFE |
| 157426 | Red | Ultra Clean Silicone/PTFE |
| 157427 | Blue | Ultra Clean Silicone/PTFE |
| 157428 | Gold | Ultra Clean Silicone/PTFE |
| 157429 | Green | Ultra Clean Silicone/PTFE |
Pre-cut 11 mm crimp seals
All septa are pre-slit and pre-assembled. Per 100 pieces, in 5 colours.
| Cat.nr. (zilver) | Septum |
|---|
| 156325 | Silicone/PTFE single slit |
| 156330 | Silicone/PTFE cross slit |
| 156335 | Silicone/PTFE star slit |
Colour coding: quick distinction at high throughput
All Brown aluminium crimp seals are available in 5 colours: silver, red, blue, gold and green. Colour coding is particularly practical for:
- Multiple projects or methods running simultaneously on one autosampler
- Distinguishing samples with different concentrations or matrices
- Quick visual check of whether a vial has already been opened
Every septum variant is available in all 5 colours, so you can combine colour coding with your preferred septum material.
Crimp seals for headspace vials (20 mm)
For headspace vials, Brown supplies 20 mm aluminium crimp seals, including pressure relief versions. See our page on magnetic crimp seals and headspace vials for the complete overview.
When do you choose crimp seals over snap caps or screw caps?
Aluminium crimp seals offer the most hermetic seal of all closure types and are the most resistant to internal pressure. They are the standard choice for GC analysis where the vial is heated or where the autosampler builds up pressure in the vial for injection.
For applications where speed and convenience matter more than maximum sealing, you can also choose snap-on caps (no crimper needed) or screw caps. We are happy to advise which closure best suits your system and application.