137

A  triple  quadrupole  mass  spectrometer  was  applied  in  the  ECNI  mode  (1200L,  Varian,
Walnut  Creek,  USA).  Regular  performance  optimisation  of  both  quadrupoles  was
carried  out.  The  temperature  of  the  transfer  line  was  280  °C,  of  the  ion  source  200  °C
and  of  the  manifold  40  °C.  Methane  was  used  as  reagent  gas  (99,995  %,  Carbagas,
Switzerland)  at  a  pressure  of  7.3  mbar  (5.5  Torr).  The  dwell  time  was  0.25  ms  per  ion
group.  Table  42  and  Table  43  summarised  the  selected  masses  in  the  selected  ion
monitoring  mode.

Table  43:  Mass-to-charge  ratios  of  ion  selected  for  the  internal  standards  e-HCH  and  n C w -transchlordane
  as  well  as  for  other  polychlorinated  compounds  included  during  method  development.  The
ECNI-MS  mode  was  applied.

Compound

Ion

m/z

m/z  most  abundant
isotope

a-HCH

[M-Clf

253

255

e-HCH

[M-Clf

253

255

’  C  i  o  -''  ' v -C  h  1  o  rd  a  n  e

[MP

416

420

r/.v-Chlordane

[M]-406



410

rz.v-Xonachlor

[M]-440



444

Heptachlor

[M-2C1]"

299

302

Octachloronaphthalene

[M-2C1]"

332

334

p,p’-DDT

[M+H-3C1] -

248

248

PCB  153

[M]-358



360

Toxaphene  #44

[M-Clf

373

377

Toxaphene  #62

[M-Clf

373

377

rra/z.v-Chlordane

[Mf

406

410

rra/z.v-\o  nach  lor

[Mf

440

444

5.6.6  Quantification  of  PCAs  by  ECNI-HRMS
A  comparison  between  ECNI-HRMS  and  ECNI-LRMS  combined  with  the  newly
developed  clean-up  was  carried  out  to  ensure,  that  the  latter  has  the  necessary  selectivity
for  PCA.  The  ECNI-HRMS  measurements  were  carried  out  at  the  Norwegian  Institute
for  Air  Research  (Kjeller,  Norway).  Results  obtained  by  LRMS  and  HRMS  were  well
comparable  (see  chapter  5.3.3.3).