Warnings that dirty stirrer bars can act as phantom catalysts
Metal contaminants that can’t be removed by cleaning can be a serious problem for sensitive reactions
Contaminated stirrer bars could be ruining a whole host of experiments that are extremely sensitive to the presence of even minute amounts of metal catalysts. The Russian research team found that regular cleaning procedures often do not remove all the contaminants from the surface of the bars. They recommend running control experiments with unused stirrer bars to solve the problem but say that such impurities could also offer new opportunities in catalysis.1