Anhydrous and Air-Sensitive Reagents

By: Todd Halkoski, Chemfiles Volume 10 Article 2

           Todd Halkoski

Todd Halkoski
Market Segment Manager
Email:todd.halkoski@sial.com

The Ideal Solution for Anhydrous and Air-Sensitive Reagents

As the leader in air-sensitive chemistry, Sigma-Aldrich carries by far the largest breadth of anhydrous solvents and air-sensitive reagents to service the research market. In the late 1970’s, Dr. Clint Lane developed the Sure/Seal bottle to protect sensitive reagents from oxygen and moisture. This not only maintained product integrity, but also facilitated the use of these products.

Our traditional Sure/Seal is now undergoing major improvements. During the upcoming months, you will begin experiencing the value of these new design improvements.

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New Crimp Cap Design

  • Increased puncture area by 4x to accommodate multiple punctures
  • Crimp cap helps maintain product quality by providing an air-tight system

New Aldrich Sure/Seal

New Aldrich Sure/Seal


Previous Aldrich Sure/Seal

Previous Aldrich Sure/Seal

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New Plug Style

  • Maximimizes surface area contact with the bottle to prevent moisture and oxygen entry
  • More than 50% thicker than competing brands

New plug style

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New Elastomer Liner

Provides outstanding resealing properties

  • Secondary resin layer ensures resistance to chemicals
  • Outperforms competing seals with respect to moisture uptake

New Aldrich Sure/Seal System

Unpunctured

Unpunctured


4 Punctures

4 Punctures


Competitor A System

Unpunctured

Unpunctured


4 Punctures

4 Punctures

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Aldrich Sure/Seal Testing Results

To illustrate the effectiveness of the new Aldrich Sure/Seal, our design was tested against another supplier, which also sells similar anhydrous solvents. Specifically, we compared their performance based upon:

  1. The liners ability to seal and maintain product quality after repeated punctures. Specifically, we measured the rate of moisture gain by Karl Fischer analysis over a five-week testing period.
  2. The amount of oxygen allowed to permeate into the bottle over a period of time. The Oxygen Transmission Rate (OTR) testing demonstrates the cap and liners ability to maintain an airtight seal when both unpunctured and punctured.
  3. The integrity of the liner to hold its shape and continue to perform in a laboratory setting after receiving numerous punctures without risk of liner degradation, deformation or catastrophic failure.

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Karl Fischer Analysis

Utilizes a coulometric titration method to measure the rate of moisture uptake. To determine the effectiveness of the liner’s seals and closure design, a five-week study was conducted.

Karl Fischer Analysis

Comprehensive testing confirms the New Aldrich Sure/Seal outperforms other products on the market by maintaining low water absorption even after multiple punctures.

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Oxygen Transmission Rate Testing

To demonstrate the effectiveness of our new Aldrich Sure/Seal, we evaluated it against another supplier to see how each performed when tested for the amount of oxygen allowed to permeate into the bottle.

Oxygen Transmission Rate Comparison

* Liners were punctured 4 times with an 18-gauge needle, and overlaps were torqued to 40 in lbs.

OTR testing demonstrates the new Aldrich Sure/Seal sustains product quality better than the competition.

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Liner Integrity

When using air-sensitive solvents and reagents, liners should not only seal to maintain product quality, but also consistently hold form after repeated puncture. The New Aldrich Sure/Seal gives you the assurance of safety and a quality product.

Toluene Testing—5 Weeks (20 punctures)
Competitor A

Competitor A


New Sure/Seal System

New Sure/Seal System

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Materials

     
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