Figure 4.

Sorption isotherms of benzalkonium chlorides to well plate plastic. Isotherms were fit using the Freundlich equation (R² of all fits >0.95). In panel (a), estimated concentrations sorbed to the plastic in 96-well plate wells without cells are correlated with concentrations in medium without medium constituents. In panel (b), measured concentrations in medium after exposure are correlated with concentrations in medium without medium constituents before exposure. No sorption to plastic occurs on the 1:1 line.