Determination of organochlorine and organophosphate pesticide residues in water from the rivers of Davao City by gas chromatographic-mass spectrometric analysis

• Main Authors: Reyes, Ronald L., Guidote, Armando M., Jr., Simpol, Lourdes R., Mindo, Roland Anthony, Alim, Nathan Ray A., Kate, Kathyna M., Enero, Jodell Ryan T., Gumanao, Paul Randy P.
• Format: text
• Published: Animo Repository 2012
• Subjects: Pesticides—Environmental aspects—Philippines—Davao City; Chemistry; Environmental Studies
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/8729
• Institution: De La Salle University

Organochlorine and organophosphate pesticides comprise a large group of structural diverse compounds used in the control of agricultural pests. Four major rivers were sampled to evaluate the levels of organochlorine and organophosphate pesticide residues namely: eight (8) sampling stations along Talomo River, four (4) sampling stations along Lipadas River, five (5) sampling stations along Tagluno River, and eight (8) sampling stations in Panigan-Tamugan Rivers. Water samples were extracted by liquid-liquid extraction and analyzed using a gas chromatograph coupled with mass spectrometer detector. A total of ten (10) pesticide residues were identified, and five (5) of the ten are classified banned by the Fertilizers and Pesticides Authority of the Department of Agriculture of the Philippines. The banned pesticides detected in the samples were dieldrin, aldrin, endrin aldehyde, y-chlordane, and B-heptachlorepoxide. The other pesticides identified were penthoate, malathion E50, chlorothalonil, chlorpyrifos, and dichlorodiphenyldichloroethylene (DDE). Concentrations of some detected organochlorine and organophosphate pesticides in water were relatively higher as compared to guideline values set by United States Environmental Protection Agency (US EPA) and by the International Union of Pure and Applied Chemistry (IUPAC) and thus present a threat to various sources of clean water in the locality. Keywords: organochlorine pesticides, organophosphate pesticides, GC-MS, pesticide contaminants, guideline values.