Determination of azoxystrobin residue in Panax ginseng and Panax quinquefolium and dietary intake risk assessment

A method for the determination of azoxystrobin residues in Panax ginseng and Panax quinquefolium was described.The residues were extracted with acetonitrile-water V (acetonitrile):V (water)=7:1 assisted by ultrasonic,cleaned up with florisil-neutral alumina-activated charcoal (5:3:0.15, m:m:m) mixed column and dichloromethane by means of liquid-liquid partition.Quantitative analysis was performed with gas chromatography equipped with ECD (electronic capture detector).The fortified recoveries and relative standard deviation (RSD) were 82.1% -97.8% and 1.6% -6.2% in Panax ginseng,90.9% -92.0% and 1.6% -3.1% in Panax quinquefolium,at three spiked levels(1,0.5 and 0.01 mg/kg).The limit of detection(S/N =3) was 0.06 ng and the limit of quantification (LOQ) of the detection method was 0.01 mg/kg.The method was applied to monitor the residue status of azoxystrobin in some representative Panax ginseng and Panax quinquefolium planting areas and make risk assessment in 2010.The result of the study showed that the maximum residue in the sample was 0.1 mg/kg.By calculating,risk quotient(RQ) was very low and the residue could be declined to the safe level.