<p>Reactions
carried out in the presence of rubber septa run the risk of additives being
leached out by the solvent. Normally, such species are present at low enough
levels that they do not interfere with the reaction significantly. However,
when studying reactions using sensitive methods such as mass spectrometry, the
appearance of even trace amounts of material can confuse dynamic analyses of
reactions. A wide variety of additives are present in rubber along with the
polymer: antioxidants, dyes, detergent, and vulcanization agents, and these are
all especially problematic in negative ion mode. A redesigned Schlenk flask for
pressurized sample infusion (PSI) is presented as a means of practically
eliminating the presence of contaminants during reaction analyses.</p>
