<prompt> Which organophosphate is NOT an aryl phosphate?ParathionTik-20MalathionParaoxon  <response>: All are aryl phosphate except malathion which is a alkyl phosphate. Alkyl phosphates are: HETP TEPP Tetron OMPA Dimefox Isopestox Malathion Kill bug; Bugsolin Sulfotepp Demeton Trichlorfon Aryl phosphates are: Parathion nitrostigmine Follodol; Kill phos; Ekato Paraoxon Methyl-parathion Metacide Chlohion Diazinon Diazion; Tik 20 Ref: The essentials of forensic medicine and toxicology by Dr K S Narayan Reddy, 27th edition, Page 457. 