A simple spectroscopic method to determine dimethoate in water samples by complex formation

• Published in: Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes Vol. 55; no. 4; pp. 310 - 318
• Main Authors: Romero-Natale, Aline, Rebollar-Pérez, Georgette, Ortiz, Irmene, Tenorio-Arvide, María Guadalupe, Munguía-Pérez, Ricardo, Palchetti, Ilaria, Torres, Eduardo
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 02-04-2020; Taylor & Francis Ltd
• Subjects: Coefficient of variation; Complex formation; detection assay; Dimethoate; Dimethoate - analysis; Dimethoate - chemistry; Environmental monitoring; Groundwater; Groundwater - analysis; Groundwater - chemistry; Herbicides; Herbicides - analysis; Herbicides - chemistry; Lagoons; Limit of Detection; metal dipyrrinate; Nickel; Organic matter; organophosphorus pesticide; Quantitation; Response time; Rivers - chemistry; Salts; Selectivity; Sensitivity and Specificity; Spectrophotometry - methods; Spectrum Analysis; Stoichiometry; Sulfates; Waste Water - analysis; Wastewater treatment; Wastewater treatment plants; Water - analysis; Water - chemistry; Water Pollutants, Chemical - analysis; Water sampling; metal dipyrrinate; organophosphorus pesticide; detection assay; Dimethoate
• ISSN: 0360-1234; 1532-4109
• DOI: 10.1080/03601234.2019.1696095

A simple and rapid method for the determination of dimethoate in water was developed based on the monitoring of the complex formation between bis 5-phenyldipyrrinate of nickel (II) and the herbicide dimethoate. The method showed a short response time (10 s), high selectivity (very low interference from other sulfate and salts), high sensitivity (limit of detection (LOD) 0.45 µM, limit of quantitation (LOQ) of 1.39 µM), and a K
d
of 2.4 µM. Stoichiometry experiments showed that complex formation occurred with a 1:1 relation. The method was applied to different environmental water samples such as lagoon, stream, urban, and groundwater samples. The results indicated that independently from the water source, the method exhibited high precision (0.25-2.47% variation coefficient) and accuracy (84.42-115.68% recovery). In addition, the method was also tested using an effluent from a wastewater treatment plant from Mexico; however, the results indicated that the presence of organic matter had a pronounced effect on the detection.