Velkoska-Markovska, L. and Petanovska-Ilievska, B. 2013. Optimization and development of SPE-HPLC-DAD method for the determination of atrazine, malathion, fenitrothion and parathion pesticide residues in apple juice. Macedonian Journal of Chemistry and Chemical Engineering. 32, 2 (Dec. 2013), 299–308. DOI:https://doi.org/10.20450/mjcce.2013.449.