A single-step pesticide extraction and clean-up multi-residue analytical method by selective pressurized liquid extraction followed by on-line solid phase extraction and ultra-high-performance liquid chromatography-tandem mass spectrometry for complex mat

• Potential hazards of pesticides should be determined to support environmental risk.
• Research establishing pesticide residue levels in complex matrices are missing.
• Analytical challenges arise to successfully determine these levels in complex matrices.
• A multi-residue analytical method for complex matrices was developed and validated.
• Developed methods were successfully applied to real environmental marine samples.

Pesticides, a group of compounds linked to human activity, may, when in toxic levels, have a profound effect on water quality, and hence result in adverse consequences to aquatic life and ultimately to human health. Analytical challenges arise when successfully trying to determine these levels in environmental complex matrices. Therefore, fast, simple, sensitive and selective analytical methodologies for multi-residue determination of pesticides (atrazine, azoxystrobin, bentazon, λ-cyhalothrin, penoxsulam and terbuthylazine) in sediment, macrophytes (algae and aquatic plants) and aquatic animals were developed and validated. The established methods were matrix-dependent and were based on Selective Pressurized Liquid Extraction (SPLE) followed by on-line Solid Phase Extraction and Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (on-line SPE-UPLC-ESI–MS/MS). This cutting-edge research methodology uses a small amount of sample, is time saving and reduces the use of organic solvents in compliance with Green Chemistry principles. The analytical features were adequate for all compounds in all studied matrices. The established methodology was applied on real marine samples and no pesticide concentrations above their respective method quantification limits were measured in sediments or aquatic plants. However, terbuthylazine was found in the macroalgae Ulva spp. (108 ng g−1 dw) and all the prospected pesticides were measured above their respective method quantification limits in the bivalve Scrobicularia plana (atrazine: 48 ng g−1 dw, azoxystrobin: 64 ng g−1 dw, bentazon: 33 ng g−1 dw, λ-cyhalothrin: 2531 ng g−1 dw, penoxsulam: 50 ng g−1 dw, and terbuthylazine: 44 ng g−1 dw).