GC Analysis of Some Organochlorine Pesticides using a Brominated Internal Standard

Abstract The brominated compound 1,1 -bis(4-chloropheny 1)2-bromoethane was specifically synthesized for use as internal standard (IS) in the GC analysis of some organochlorine pesticides. The IS was prepared by reacting commercially available 2,2-bis(4-chlorophenyl)ethanol with triphenylphosphine and tetrabromomethane. Organochlorine pesticides were tested together with this IS for the linearity of the analytical method in the pg range of injected pesticides (HCB, α- and γ-HCH, heptachlor, aldrin, op'-and pp'-DDT and its metabolites: op'-and pp'-DDE, op'- and pp'-DDD), using MS detection in the negative ion chemical ionization mode (NICI). GC-ECD was also used to test the IS response and linearity of the method for some of the above pesticides in the pg range of injected analytes. The synthesized IS was added and analyzed in vegetable samples (spruce needle and branch) to prove the applicability of this compound in a GC-NICI-MS analytical method for organochlorine pesticides in such samples.