Sentence:  Carrier * * f was added and the aqueous and organic <WSD>phases</WSD> were separated ( cells containing gaseous reactants were immersed in liquid air before opening under sodium iodide ) . 
Meaning of the word marked with <WSD> tags:  (physical chemistry) a distinct state of matter in a system; matter that is identical in chemical composition and physical state and separated from other material by the phase boundary