[Determination of five pyrethroid pesticides residues in Anoectochilus roxburghii by cloud point extraction-back extraction and GC-MS].

A method for residual determination of 5 pyrethroid pesticides in Anoectochilus roxburghii by cloud point extractionback extraction-GC-MS was established.PEG 6000 was used as extraction agent and isooctane was used for back-extractant.The content was calculated by external standard method.The linear range was from 15 to 2 000 μg·kg- 1 with the good correlation coefficients(0.955-0.999).The recoveries at spiked concentrations of 50-500 μg·kg- 1 ranged from 85.12% to 101.6%.The limit of detection and quantification of 5 pyrethroid pesticides were in the range of 0.63-3.10 μg·kg- 1 and 2.10-10.31 μg·kg- 1,respectively.The proposed method can be applied to the determination of pyrethroid pesticides residues in A.roxburghii.