Abstract: The instant invention is a method for converting particulate silicon into monocrystalline silicon suitable for the determination of contaminates present in the particulate silicon. The method uses a silicon vessel, with known levels of the contaminates to be determined, to contain the particulate silicon. The silicon vessel, containing the particulate silicon, is float-zone processed to form a monolithic unit of monocrystalline silicon. The concentration of contaminates in the monocrystalline silicon can then be determined by the more sensitive analytical methods known for analysis of monolithic, monocrystalline silicon. The instant method is especially useful for measuring very low levels of aluminum, boron, phosphorous, and carbon in particulate silicon.