The preparation and use of gas and liquid mixtures has progressed dramatically over the past decade. Advances in preparation and analytical methodology have greatly increased the reliability and diversity of such mixtures.
Physical and safety limitations restrict or limit the feasibility of preparing some mixtures. Physical limitations can include purity limitations, reactivity, or vapor pressure restrictions. Safety limitations can include reactivity, the selection of appropriate containers, valves, safety devices, and the meeting of other regulations in accordance with DOT requirements and International ocean and aircraft shipping laws, or other applicable regulations.
Gravimetric techniques are utilized to prepare the majority of the complex mixtures commercially available today. Gravimetric techniques involve measuring the amount of gas present in a cylinder by weight with high capacity, high accuracy balances. This technique is independent of compressibility and temperature. The complexity and accuracy of mixtures is only limited by purity of starting materials, reactivity of components, and the sensitivity of the balance utilized versus the mass measured. The most reliable of mixtures are gravimetrically prepared and independently confirmed by analytical methodology.
Accurate Gas Products, L.L.C. (AGP) manufactures mixtures using gravimetric balances. Each component is analyzed for purity before it is used. After the mixture has been blended, it is analyzed to certify that all components are in the mixture and at the appropriate levels.
The variety and diversity of gas and liquid mixtures utilized make a comprehensive listing of such mixtures impossible.
A partial listing of classes of compounds that have been utilized in gas or liquid mixtures includes: