Products like the LifeStraw/Sawyer/Katadyn won't filter most chemicals. To remove
some chemicals you need to use distillation and distillation is only good if the boiling point of a given chemical is higher than that of water.
LifeStraw even states
>Chemicals, salt water, heavy metals and viruses will not be removed.
http://help.lifestraw.com/en/articles/2507813-does-the-lifes...
Sawyer states
>Taste
>The Sawyer filter removes taste that comes from bacteria, dirt, and green matter.
>Chemicals
>The Sawyer filter does NOT remove iron, sulfur, other chemicals, or simple compounds. Taste can be masked by using flavor additives like Gatorade or crystal light (filter needs to be cleaned immediately after using them).
>Heavy Metals
>The Sawyer filters are not made with charcoal. While other portable filters have charcoal, they lack in amount of media and adequate dwell time. Therefore, they only remove small amounts of heavy metals, pesticides, etc. (when used in real life applications). Try using better sources of water, if possible.
https://sawyer.com/water-filtration/faqs/