2010/12/15 · Determination of peak area was accomplished by a gas chromatograph (Clarus 500, GC System, Perkin Elmer, USA) with a headspace sampler (HS 40, Perkin Elmer, USA). For simultaneous determination of diacetyl and pentanedione, 10 mL sample was collected in vials and detected using an electron capture detector (ECD) which contains a radioactive resource Ni 63 .