135 
temperature programme was employed: 100 °C isothermal for 2 min, with 15 °C/min to 
280 °C, isothermal for 8 min or alternatively 100 °C isothermal for 2 min, with 10 
°C/min to 260 °C, isothermal for 10 min. 
An HP 5989B mass spectrometer was applied in the ECNI mode (Hewlett Packard, Palo 
Alto, USA). Regular performance optimisation was carried out with perfluoro- 
tributylamine selecting the mass fragments m/z 283.0, 414.0 and 453.0. The temperature 
of the transfer line was 280 °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 42 and Table 43 summarise the selected masses in the 
selected ion monitoring mode. The most abundant chlorine isotope signal was selected 
for quantification and the second one for confirmation. 
Formula and congener patterns were determined on a CP-3800 (Varian, Walnut Creek, 
USA) gas chromatograph. A fused silica capillary was employed of 15 m length and 
0.25 mm ID coated with a 0.25 pm film of DB5-MS (5 %-phenyl-95 %-methylsiloxane, 
J&W Scientific, Folsom, USA). The injected volume was 2.0 pi in the splitless mode (3 
min splitless time) using an autosampler (Combi Pal autosampler, CTC Analytics, 
Switzerland). The injector temperature was 275 °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: 100 C isothermal for 2 min, with 10 
°C/min to 260 °C, isothermal for 10 min.