  The removal of radioactivity from liquid scintillator has been studied in
preparation of a low background phase of KamLAND. This paper describes the
methods and techniques developed to measure and efficiently extract radon decay
products from liquid scintillator. We report the radio-isotope reduction
factors obtained when applying various extraction methods. During this study,
distillation was identified as the most efficient method for removing radon
daughters from liquid scintillator.
