title: Organophosphorous residue in Liza aurata and Cyprinus carpio.
abstract: OBJECTIVE
  To determine the amount of azinphos methyl and diazinon residues in two river fishes, Liza aurata and Cyprinus carpio, in the north of Iran.
  
  
  METHODS
  This study was done during 2006-2007. In this survey, 152 water and fish samples from Gorgan and Qarasu rivers, north of Iran, were investigated. Sampling was done in three predetermined stations along each river. Organophosphorus compounds (OPs) were extracted from the fishes and the water of rivers. After extraction, purification and concentration processes, the amount and type of insecticides in water and fish samples were determined by high performance thin layer chromatography (HPTLC).
  
  
  RESULTS
  There was a significant difference in the residue of the insecticides in the water and fish samples between summer and other seasons in the two rivers. The highest amount of insecticides residue was seen during summer. In both rivers, the amount of diazinon and azinphos methyl residues in the two fishes was more than 2 000 mg/L in summer. There was no significant difference in insecticides residue between the fishes in two rivers. The diazinon residue was higher than the standard limits in both rivers during the spring and the summer, but the residual amount of azinphos methyl was higher than the standard limits only during the summer and only in Qarasu River.
  
  
  CONCLUSIONS
  It can be concluded that the amount of OPs in the water and the two fishes, Liza aurata and Cyprinus carpio, is higher than the permitted levels.
authors.affiliation: Department of Medical Entomology, Faculty of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mansoreh
authors.initials: M
authors.lastname: Shayeghi
authors.forename: Mehdi
authors.initials: M
authors.lastname: Khoobdel
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Bagheri
authors.forename: Mohammad
authors.initials: M
authors.lastname: Abtahi
authors.forename: Hojjatollah
authors.initials: H
authors.lastname: Zeraati
mesh_terms: D000818:Animals; D001387:Azinphosmethyl / Q000032:analysis* / Q000302:isolation & purification; D002800:Cholinesterase Inhibitors / Q000032:analysis* / Q000302:isolation & purification; D003976:Diazinon / Q000032:analysis* / Q000302:isolation & purification; D005399:Fishes; D007492:Iran; D010755:Organophosphates / Q000032:analysis* / Q000302:isolation & purification; D045483:Rivers; D012621:Seasons; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D002800:Cholinesterase Inhibitors; D010755:Organophosphates; D014874:Water Pollutants, Chemical; D014867:Water; D001387:Azinphosmethyl; D003976:Diazinon
keywords: Cyprinus carpio; Fish; Insecticides; Iran; Liza aurata; Organophosphorus; Residue; River fish; Water contamination