Direct Determination of the Environmental Contaminant Acid 2,4-diclorofenoxiacetic in Natural Waters by Solid Surface...

2,4-Dichlorophenoxyacetic acid (2,4-D) is a selective, low-volatility, systemic herbicide. It is used to control broadleaf weeds in certain crops, such as rice, corn, and wheat. The use of 2,4-D has become widespread in both the agricultural and industrial sectors, with the serious drawback that 2,4-D residues can contaminate food, soil, and groundwater sources. It has been classified as a group 2B carcinogen by the International Agency for Research on Cancer. This paper proposes the development of a new alternative methodology to traditional techniques for the control and monitoring of 2,4-D in natural water samples from agricultural areas surrounding the Quinto River in the province of San Luis. The herbicide was quantified directly, in the presence of the anionic surfactant SDS, the systems were filtered through blue band filter paper as a solid support, prior to determination by solid surface fluorescence (SSF) (λ_exc = 555 nm; λ_em = 580 nm). Under optimal working conditions, a detection limit and a quantification limit of 0.33 and 0.90 ng L^- 1, respectively, with a linearity range of 0.90 to 1.13 × 10³ ng L^- 1. The proposed methodology was applied to natural water samples from agricultural areas, adjacent to the Quinto River in the province of San Luis, representing an innovative alternative to conventional methods for 2,4-D monitoring. The concentrations found were near to 3 ng L^- 1. Additionally, among the advantages of the new method, it is important to highlight the generation of low volumes of waste, preserving the environment and thus contributing to some principles of green chemistry.