What technique separates components of a mixture based on their tendency to travel across another material?

The technique that separates components of a mixture based on their tendency to travel across another material is chromatography. In this process, a mixture is usually dissolved in a solvent and then passed over a stationary phase, which is often a solid or a gel. Different components of the mixture will interact differently with the stationary phase and the solvent, causing them to travel at varying rates. This results in the separation of the components, and they can be identified and quantified based on their distinct movement through the medium.

Chromatography is widely used in many fields, including chemistry, biology, and environmental science, to analyze substances and is an essential tool in laboratories for separating mixtures into their constituents.

The other methods mentioned in the question serve different purposes: a spectrograph analyzes light to provide information about the properties of materials, a centrifuge separates materials based on density through rapid spinning, and filtration removes particles from a fluid by passing it through a barrier. While all these methods are effective for specific types of separation, none utilize the principle of differential travel across a medium like chromatography does.