141

with  a  025  pm  film  of  DB5-MS  (5%  phenyl-95  %-methylsiloxane,  J&W  Scientific,
Folsom,  USA).  The  injected  volume  was  1.5  pi  in  the  splitless  mode  (2  min  splitless
time).  The  injector  temperature  was  240  °C.  He  was  used  as  carrier  gas  (99,999  %
purity,  Carbagas,  Switzerland)  at  a  head  pressure  of  68,9  kPa  (10  psi).  The  following
temperature  programme  was  employed:  90  °C  isothermal  for  2  min,  with  30  °C/min  to
150  °C,  then  4  °C/min  to  250  °C,  2  min  isothermal.
Also  here  an  HP  5989B  mass  spectrometer  was  applied  in  the  ECNI  mode  (Hewlett
Packard,  Palo  Alto,  USA).  The  temperature  of  the  transfer  line  was  250  °C,  of  the  ion
source  200  °C  and  of  the  quadrupole  100  °C.  Methane  was  used  as  reagent  gas
(99,995  %,  Carbagas,  Switzerland)  at  a  pressure  of  1-1.6  hPa  (0.9-1.1  Torr).
Table  45  summarises  the  selected  masses  for  chlordanes  in  the  selected  ion  monitoring
mode.  The  most  abundant  chlorine  isotope  signal  was  selected  for  quantification  and  the
second  one  for  confirmation.  The  metabolites  oxy-chlordane,  trans-  and  c/.s-hcptachlorepoxide
  could  not  be  completely  separated  on  the  selected  capillary.  c/.s-Hcptachlorepoxide
  and  oxy-chlordane  co-eluted  in  front  of  /ran.s-hcptachlorcpoxidc.  Quantification ­
  of  cis-heptachlorepoxide  was  therefore  carried  out  with  the  not  disturbed  but
less  abundant  mass  m/z  388  and  of  oxy-chlordane  with  m/z  424.  The  presence  of  the
chlordanes  MC5  and  MC7  was  confirmed  by  their  retention  relative  to  c/.s-chlordanc
(MC5:  0,982;  MC7:  1,021,  (Karlsson,  1999;  Karlsson  etal.,  2000)).