Biomimetic Chromatography as a High-Throughput Tool for Screening Bioaccumulation and Acute Aquatic Toxicity of Pesticides

Modern pesticide risk assessment relies on data on bioaccumulation and acute aquatic toxicity, yet generating such data is labour-intensive and animal-demanding. This study evaluated whether phospholipid affinity of pesticides, quantified by the chromatographic hydrophobicity index CHI_IAM obtained from high-throughput gradient biomimetic chromatography, can serve as a surrogate descriptor of these endpoints. Nineteen pesticides representing different chemical and functional classes were analyzed on IAM.PC.DD2 columns, and CHI_IAM values were determined. Bioconcentration factors (BCF) in fish and acute toxicity data (96 h LC₅₀ for fish, 48 h EC₅₀ for <i>Daphnia magna</i>) were retrieved from the Pesticide Properties DataBase. CHI_IAM ranged from -12.1 to 54.8 and correlated strongly with log₁₀BCF (r = 0.84) and log₁₀LC₅₀ in fish (r = -0.84), and moderately with log₁₀EC₅₀ for <i>Daphnia</i> (r = 0.76). Highly lipophilic pesticides with high CHI_IAM showed elevated BCF and low LC₅₀/EC₅₀ values, whereas polar compounds with low CHI_IAM exhibited negligible bioconcentration and low acute toxicity. Deviations from these trends, for compounds with specific modes of action, highlighted the contribution of mechanisms beyond membrane toxicity. Overall, CHI_IAM measured under high-throughput conditions retains prognostic value for ecotoxicological assessment and may serve as a rapid experimental descriptor to support preliminary screening.