Keywords: Chemcatcher monitoring Substances: clarithromycin (AGOYDEPGAOXOCK-KCBOHYOISA-N) fipronil (ZOCSXAVNDGMNBV-UHFFFAOYSA-N) diuron (XMTQQYYKAHVGBJ-UHFFFAOYSA-N) 2.4-D (OVSKIKFHRZPJSS-UHFFFAOYSA-N)