What material are the lids of sample jars lined with?

The lids of sample jars are typically lined with Teflon because it is a chemically resistant material that does not react with most substances. This characteristic is crucial when handling samples that may contain reactive or volatile compounds, ensuring that the integrity of the sample is maintained and preventing contamination. Teflon's non-stick properties also facilitate easy removal of the samples from the containers without residue. This makes it an ideal choice for laboratory settings, particularly in marine science and environmental monitoring where sample accuracy and preservation are paramount. Other materials like plastic or rubber might not provide the same level of chemical resistance or could alter the sample’s properties over time.