Riverlady,
I assume your using a typical water filter which contains granulated carbon. If so, it will filter out the compounds. With respect to the word "trace", it does have a scientific definition. I believe it means, we know it's there but it is in quantities so small it can't accurately quantified.
The are loads of trace chemicals in our drinking water. I'm sure I could find fecal matter, lead, iron, dioxin, radioactive materials in a large enough sample with the right equipment.
MikeCJ