Accumulation, metabolites formation and elimination behavior of rac-glufosinate-ammonium and glufosinate-P in zebrafish (Danio rerio)

Abstract

An efficient trace detection method for the determination of residues of the glufosinate enantiomers and metabolites in zebrafish by HPLC-Q-Exactive Orbitrap Mass Spectrometry was developed. After the purification of dichloromethane and Oasis PRiME HLB SPE column, the recovery ranges from 77% to 104%, with RSD < 10.03%. The limits of quantitation in zebrafish were 0.006-0.02 mg/kg. The results revealed zebrafish absorbed glufosinate slowly, reaching a steady state in 10-14 days, and the bioaccumulation factor (BCF) of D/L-glufosinate-ammonium was less than 0.3. L-glufosinate-ammonium accumulated preferentially in zebrafish. The residue of the metabolite N-acetyl glutamate (NAG) was smaller than that of 3-methyl phosphonic acid (MPP). D/L-glufosinate-ammonium had an elimination half-life of less than 2.3 days during the elimination phase. The bioaccumulation and elimination behavior of glufosinate-ammonium in zebrafish aquatic system was shown in this work, which offered scientific data for assessing the food safety of rac-glufosinate-ammonium and glufosinate-P (pure L-glufosinate-ammonium) in fish.

Keywords: Bioaccumulation; Degradation; Glufosinate-P; Metabolites; Rac-glufosinate-ammonium; Zebrafish.

Fig. 1

Recovery results under different extraction and purification conditions (level 0.1 mg/kg, n = 3) (A: Volume of extract solvent; B: Ultrasonication time; C: Different agents for liquid–liquid extraction; D: Volume of CH₂Cl₂₎.

Fig. 2

Bioaccumulation and purification of rac-glufosinate-ammonium in zebrafish (A) at low concentration (2 µg/mL) (B) at high concentration (10 µg/mL).

Fig. 3

The concentration and BCF values of glufosinate-P in zebrafish (A) The concentration (B) The BCF values.

Fig. 4

Metabolites of glufosinate in zebrafish. (A) The NAG, (B) The MPP.