This dataset contains raw experimental data generated in a study investigating the adsorption–desorption behavior of paraquat and diquat in different soils, as well as the development of the analytical method used for their determination. No processed or fitted data are included. The dataset is intended to ensure transparency and enable independent data treatment, modeling, and interpretation. The dataset is organized into the following components: Soil Characterization Data Raw measurements of physicochemical properties of the studied soils, including parameters such as pH, organic matter content, cation exchange capacity (CEC), and texture. Analytical Method Development Data Raw experimental data obtained during method development, including instrumental responses under different conditions, extraction tests, and evaluation of potential matrix effects. Calibration Data Raw calibration data, including concentration levels and corresponding instrumental responses for paraquat and diquat. A representative calibration dataset is provided as an example. Kinetic Adsorption Data Time-dependent raw data describing adsorption experiments, reported as the amount of analyte in solution and/or adsorbed phase as a function of time. Adsorption and Desorption Isotherm Data Raw equilibrium data, including initial and final concentrations in solution for adsorption and desorption experiments, allowing the construction of isotherms. Data for Distribution Coefficient (Kd) Determination Raw experimental measurements used for the calculation of distribution coefficients (Kd), including concentrations in solution and solid phases under equilibrium conditions. All files are provided in spreadsheet format, with variables, units, and experimental conditions clearly indicated. Data processing, modeling (e.g., kinetic or isotherm fitting), and parameter calculations are not included and should be performed by the user.