Analysis of seven adjuvants in emulsifiable concentrate with headspace gas chromatography

A method was investigated to determine the seven harmful adjuvants including dichloromethane,trichloromethane,1,1,1-trichloroethane,benzene,1,2-dichloropropane,tetrachloro-ethylene,1,1,2,2-tetrachloroethane in 25% chlorpyrifos-abamectin emulsifiable concentrate simul-taneously with headspace (HS) and gas chromatography-flame ionization detector (GC-FID).Except tetrachloroethylene and 1,1,2,2-tetrachloroethane,the method was valuable to analyze other 5 compounds.The sample was resolved with 20% DMF and sealed in HS vial,inverted for 15 times.After keeping in ambient temperature for overnight,the sample was put into water bath for 30 min at 80℃,then HS sample was analyzed with GC-FID.The linearity was well with the determination coefficient above of 0.9950.Except tetrachloroethylene and 1,1,2,2-tetrachloroethane,the recoveries ranged from 74.4% to 102.8%.The limit of quantifications (LOQs) were 0.2-5.0 mg/L.Five emulsifiable concentrate products from the market were tested with the optimized method,and two adjuvants were detected.