Bioaccumulation of trifloxystrobin in zebrafish (Danio rerio)

A residue analytical method of trifloxystrobin in zebrafish was established by PRiME HLB solid-phase extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Based on the established method, the bioaccumulation effect of trifloxystrobin on zebrafish was estimated. The results showed that the calibration curves for trifloxystrobin was linear in the range of 0.0001-0.05 mg/L. At fortified levels of 0.0005 and 0.05 mg/L, the average recoveries of trifloxystrobin in water ranged from 86.6% to 106% with relative standard deviations (RSDs) of 5.1%-8.9%. The average recoveries in fish were 70.5%-104%, with RSDs of 1.4%-3.3% at the fortified levels of 0.01, 0.1 and 10 mg/kg. The limit of quantification (LOQ) of trifloxystrobin in water and fish was 0.0005 mg/L and 0.01 mg/kg, respectively. Based on the aquatic life benchmark (ALB) of acute toxic to fish and the LC₅₀ value of zebrafish, the bioaccumulation effect of trifloxystrobin on zebrafish was studied at six exposure doses, which included the 1/10 ALB (7.15 × 10⁻⁴ mg/L), ALB (7.15 × 10⁻³ mg/L), the 1/100 LC₅₀ (5.10 × 10⁻⁴, 1.20 × 10⁻³ mg/L), and 1/10 LC₅₀ (5.10 × 10⁻³, 1.20 × 10⁻² mg/L). After continuous exposure for 192 h, the bioconcentration factor (BCF) of trifloxystrobin ranged from 113 to 178 at different exposure doses, suggested that trifloxystrobin had a medium bioconcentration effect on zebrafish. The results indicated that in the process of application of trifloxystrobin, the ecotoxicological risk caused by the bioaccumulation effect of low concentration exposure of trifloxystrobin on aquatic species should be considered.