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DualSeal - Airtight-Double-Cap Bottled Reagents

In December 2017, we introduced our newly developed double cap system "DualSeal" for moisture/oxygen sensitive products allowing you to keep them in good condition until the last drop. We will continuously increase our usage of DualSeal across our product portfolio. Click here for examples of products using DualSeal

DualSeal bottle

Features of DualSeal

  • Air-sensitive reagents can be safely dispensed without exposure to air
  • Even after piercing the septum cap, the PTFE sheet on the blue cover cap provides sealing protection.
  • Easy to dispose of caps and bottles separately

What is DualSeal?

DualSeal consists of two parts; the blue outer cap and the white septum cap both of which can be screwed on and off.
No additional sealing is required after piercing the septum cap with a needle. Just screw the outer-cap back in place.

Blue cap

Blue cap

The blue cap has a convex structure on the inside.
By filling the space where air and moisture stay, the material is protected from moisture and oxygen even after piercing the septum cap with a needle.

White cap

White cap

The white septum cap has a wide septum surface for ease of use, and features two layers of rubber and a highly chemically resistant PTFE seal.
The septum cap body is made of polypropylene and contains a screw thread allowing for easy removal from the bottle. The septum cap is closed with high torque to ensure an airtight seal.
The rubber portion (gray) is made of two layers: butyl rubber for good sealing and PTFE for high chemical resistance. The butyl rubber layer is weak against halogenated solvents such as dichloromethane.

How to use DualSeal

  1. Clamp and secure the reagent bottle before opening.
  2. Carefully unscrew the blue outer cap only. Place the cap near the bottle while in use.
  3. To prevent air from entering the container, insert a needle with a balloon filled with an inert gas such as argon or nitrogen. Then insert a syringe needle through the septum surface of the white cap.
    Common Usage of DualSeal
  4. Fill the syringe with the required amount of liquid.
  5. Remove the syringe, inject the liquid into your reaction vessel and safely dispose of the needle.
  6. Take the blue cap and screw it tightly back in place.
  7. Unclamp the DualSeal bottle and place it in its proper storage location.


  • Do not dispose of the inlaid PTFE sheet! Keep it as it is during use! This PTFE sheet acts as a second layer air seal.
    PTFE sheet of DualSeal blue cap
  • Do not place anything on the septum cap! This will significantly reduce seal quality.
    Do not place anything on the septum cap
  • Repeated use can lead to increasing the number of holes or increasing the size of existing holes and will over time lead to an increase in air leakage. To prevent deterioration of the septum, reduce the number of injections as much as possible, or purchase a smaller bottle size.
  • In the case of halogenated solvent solutions such as dichloromethane, we recommend a minimum number of injections because the punctured area of septum butyl rubber will be invaded by the vapor of the halogenated solvent, etc. Also, after removing the syringe needle, please be careful of contamination, as the solution on the needle tip may dissolve the butyl rubber.

How to remove the septum cap

Open the septum cap only when all of the liquid has been used up and you want to prepare for the disposal of the bottle.

  1. Clamp and secure the bottle before opening.
  2. Open the septum cap by unscrewing.
    The septum-cap is tightly closed with high torque to ensure airtightness. Using tools such as water pump pliers is recommended.


  • Do not remove the septum cap without having emptied the bottle first.
  • Take extra care to avoid any spillage from your syringe.

Notes on bottle disposal

The cap and bottle can be separated for disposal.

  • Remove DualSeal by referring to "How to remove the septum cap"
  • Highly reactive reagents may be residing inside the cap. Please take the necessary precautions to avoid accidents due to exposure to oxygen or moisture.
  • Dispose of the bottle and the caps separately after ensuring that no chemical residue is left behind.

Examples of products using DualSeal

Volatile Solutions

A1884 Ammonia (ca. 4% in Methanol, ca. 2.0mol/L) 100mL
A2236 Ammonia (ca. 4% in Ethanol, ca. 2.0mol/L) 100mL and 500mL
A2237 Ammonia (ca. 4% in Isopropyl Alcohol, ca. 2.0mol/L) 100mL
B4358 1,3-Butadiene (ca. 15% in Hexane) 100mL and 500mL
B4359 1,3-Butadiene (ca. 15% in Toluene) 100mL and 500mL
B4410 1-Butene (ca. 10% in Hexane) 500mL only
B4411 1-Butene (ca. 10% in Toluene) 100mL
C2882 Chloroethane (ca. 17% in Ethyl Ether, ca. 2.0mol/L) 100mL
C2883 Chloroethane (ca. 15% in Tetrahydrofuran, ca. 2.0mol/L) 100mL and 500mL
D3948 Dimethylamine (ca. 10% in Tetrahydrofuran, ca. 2mol/L) 100mL only
D4198 Dimethylamine (ca. 11% in Isopropyl Alcohol, ca. 2mol/L) 100mL only
E0531 Ethylamine (30-40% in Methanol) 100mL
E0817 Ethylamine (30-40% in Ethanol) 100mL only
H0959 Hydrogen Bromide - Ethanol Reagent (10-20%) [for Esterification] 100mL and 500mL
H1060 Hydrogen Chloride (ca. 1mol/L in Ethyl Acetate) 500mL
H1061 Hydrogen Chloride (ca. 1mol/L in Ethyl Ether) 100mL
H1062 Hydrogen Chloride (ca. 4mol/L in 1,4-Dioxane) 500mL
H1277 Hydrogen Chloride (ca. 16% in Cyclopentyl Methyl Ether, ca. 4mol/L) 500mL only
I0909 Isobutene (ca. 8% in Dichloromethane) 100mL and 500mL
I0910 Isobutene (ca. 10% in Isopropyl Ether) 100mL
I0911 Isobutene (ca. 15% in Tetrahydrofuran) 100mL and 500mL
M1016 Methylamine (40% in Methanol, ca. 9.8mol/L) 500mL
M2108 Methylamine (ca. 7% in Tetrahydrofuran, ca. 2mol/L) 100mL and 500mL
M2323 Methylamine (ca. 9% in Ethanol, ca. 2mol/L) 100mL
M2563 3-Methyl-1-butene (ca. 15% in Dichloromethane, ca. 2.5mol/L) 100mL and 500mL
M2565 3-Methyl-1-butene (ca. 12.5% in Tetrahydrofuran, ca. 1.5mol/L) 100mL
M2813 Methyl Chloride (ca. 5.7% in Tetrahydrofuran, ca. 1mol/L) 100mL
P2295 Propyne (ca. 5% in Tetrahydrofuran, ca. 1mol/L) 100mL and 500mL
P2847 Allene (ca. 2% in Tetrahydrofuran, ca. 0.4 mol/L) 100mL and 500mL
T2268 Trimethylamine (ca. 25% in Methanol, ca. 3.2mol/L) 100mL only
T2346 Borane - Tetrahydrofuran Complex (8.5% in Tetrahydrofuran, ca. 0.9mol/L) (stabilized with Sodium Borohydride) 100mL and 500mL
T2704 Trimethylamine (ca. 13% in Tetrahydrofuran, ca. 2mol/L) 100mL
T3567 Trimethylamine (ca. 13% in Acetonitrile, ca. 2mol/L) 100mL and 500mL
T3614 Trimethylamine (ca. 8% in Toluene, ca. 1mol/L) 100mL
V0126 Vinyl Bromide (ca. 14% in Ethyl Ether, ca. 1.0mol/L) 100mL
V0127 Vinyl Bromide (ca. 12% in Tetrahydrofuran, ca. 1.0mol/L) 100mL
X0041 Hydrogen Chloride - Methanol Reagent (5-10%) [for Esterification] 100mL and 500mL
U0147 Sulfur Dioxide (ca. 8% in Tetrahydrofuran, ca. 1.2 mol/L) 100mL
U0148 Sulfur Dioxide (ca. 2.5% in Dichloromethane, ca. 0.5 mol/L) 100mL
T3957 Trifluoroiodomethane (ca. 10% in Tetrahydrofuran, ca. 0.5mol/L) 100mL
T3958 Trifluoroiodomethane (ca. 10% in Dimethyl Sulfoxide, ca. 0.6mol/L) 100mL

How to identify DualSeal packaging before placing an order

All products using DualSeal have a note in the "Packaging and Container" section on our Product Details page.

Inquiry about DualSeal

DualSeal caps alone are not offered for sale.
Please feel free to send us your questions about DualSeal.