Design and application of a solid-phase extraction device in disposable pipette tips for the quantification of...

Carbaryl is a pesticide toxic to insects, applied for pest control in several crops. Human exposure to carbaryl can be associated with cancer and other diseases, and the quantification of this compound in water for human consumption is mandatory to prevent effects on human health. This work presents an alternative for constructing a solid-phase extraction device using disposable tips with materials easily found in laboratories to quantify the carbaryl pesticide in natural water samples. Quantifications were performed by high-performance liquid chromatography with UV detection. A linear response for carbaryl was obtained between 0.075 and 0.5 mg l^-1, with a good linear correlation (R² = 0.9888). The detection and quantification limits were determined with and without the preconcentration effect, being 0.075 and 0.10 mg l^-1 for LOQ, respectively. Natural water samples were analyzed using the device for sample extraction and analyte recoveries varied from 103.6 to 123.6 %. The acetonitrile consumption per sample was only 1.4 mL for each determination, and the extraction device demonstrated the same efficiency in approximately 100 extractions without changing the sorbent. Therefore, this promising method presented efficient extraction, and adhered to the fundamentals of Green Analytical Chemistry, with lower use of organic solvents and waste generation, and higher analytical frequency.