Variables: concentration Substances: clarithromycin (AGOYDEPGAOXOCK-KCBOHYOISA-N) fipronil (ZOCSXAVNDGMNBV-UHFFFAOYSA-N) mecoprop (WNTGYJSOUMFZEP-UHFFFAOYSA-N) terbutryn (IROINLKCQGIITA-UHFFFAOYSA-N) Keywords: passive sampler pharmaceutical monitoring