Thanks! 40+ years ago I worked in a marine biology lab as a dishpig for seawater analysis and we had fun times when the annual clear out found a gallon jug of benzene at the point of panic about benzene being replaced by toluene.
If the lab is going to check for trace benzene in the water, ideally you would have some pure material for reference purposes.
Put that in perspective against industrial quantities where a hardhat operator opens the hatch on a very full compartment of a chemical tanker, looking at their mirror image reflecting up from the surface of a few hundred tonnes of cargo a few feet below.
Which is then carefully sampled and delivered to a lab where they check for trace water in the benzene.
If the lab is going to check for trace benzene in the water, ideally you would have some pure material for reference purposes.
Put that in perspective against industrial quantities where a hardhat operator opens the hatch on a very full compartment of a chemical tanker, looking at their mirror image reflecting up from the surface of a few hundred tonnes of cargo a few feet below.
Which is then carefully sampled and delivered to a lab where they check for trace water in the benzene.