134 
extraction was carried out overnight with 200 ml of n - hex an c/d i c h 1 oro m ct h an c (1+1, 
v/v). The extract was concentrated to ca. 200 |ll with a Turbo Vap (Zymark, USA), 10 
ml of /7-hexane were added twice followed by a volume reduction to ca. 200 pi. 
Sample clean-up was carried out on a glass column (length 30 cm, ID 1.3 cm) filled 
from bottom to top with: 1 g of water-free sodium sulphate, 16 g of Florisil® (60-100 
mesh, Fluka, Buchs, Switzerland, deactivated with 1.5 % of water) and 1 g of water-free 
sodium sulphate again. 
Conditioning was carried out with 30 ml of /7-hexane. After transfer of the sample, the 
pre-fraction was eluted with 60 ml of /7-hexane followed by 5 ml of dichloromethane. 
The fraction containing CP was eluted with 55 ml of dichloromethane and concentrated 
to ca. 200 pi with a Turbo Vap. 10 ml of cyclohexane were added twice and the volume 
reduced between to 100 pi. The sample was ready for quantification after volume 
reduction to 100 pi and addition of 10 ng of the recovery standard e-HCH (dissolved in 
10 pi of cyclohexane). 
Sediments with a higher TOC-content (> 1%) and Baltic Sea sediments in general 
required a further clean-up step directly after extraction. A column filled with silica 
gel/conc. sulphuric acid was employed analogue to biota to remove matrix compounds 
and a yellow to greenish colour. Only 20 g of the mixture silica gel/conc. sulphuric acid 
(44 % weight) were used and eluted with 70 ml of /7-hexane/dichloromethane (1+1, 
v/v). 
5.6.5 Quantification of PCAs by ECNI-LRMS 
Gas chromatographic separations were carried out on an HP 5890II gas chromatograph 
(Hewlett Packard, Palo Alto, USA) equipped with an Hewlett Packard 7673 auto 
sampler. 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 1.5 pi in the splitless mode (2 min splitless 
time). 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