Contamination risk of stable isotope samples during milling

摘要: Rationale Isotope analysis of wood is an important tool in dendrochronology and ecophysiology. Prior to mass spectrometry analysis, must be homogenized, a convenient method involves ball mill capable milling samples directly sample tubes. However, sample-tube plastic can contaminate during milling, which could lead biological misinterpretations. Methods We tested possible contamination whole cellulose ball-mill homogenization for carbon oxygen isotope measurements. We used multi-factorial design with two/three steel balls, two amounts (10 mg, 40 mg), times (5 min, 10 min). further analyzed abrasion by empty tubes, measured the ratios pure contaminants. Results A strong risk exists bias through contamination: δ13C value polypropylene deviated from control −6.77‰. Small fibers PTFE filter bags extraction also present as this −5.02‰. Low (10 mg) showed highest due increased (−1.34‰), concentrated (−3.38‰). Oxygen measurements were unaffected. Conclusions A homogenize within test tubes prior but not or radiocarbon analysis. There still need fast, simple contamination-free preparation procedure. Copyright © 2016 John Wiley & Sons, Ltd.