Various embodiments disclosed relate to methods and apparatus for sampling an oil composition. In various embodiments, the present invention provides a method of sampling one or more components of an oil composition. The method includes placing a fluid into a pressure chamber at a first pressure. The pressure chamber includes an oil composition therein. The oil composition contacts the fluid. The fluid includes at least one of a gas, a liquid, and a supercritical fluid. The method also includes taking a sample of at least one of the fluid and the oil composition from the pressure chamber.