77 
Table 21: Relative recoveries [%] of selected sPCA/mPCA compounds and the internal standard 13 Ci 0 - 
trans-chlordane after stepwise and complete clean-up of spiked sun flower oil or mackerel muscle tissue 
(spiked amount: 1.5-25 pg of sPCA or 1.5-20 pg of mPCA mixture). 
No. of Relative recoveries mPCAs [%] 
parallels C U I1 2 ,CI 7 C, 5 H 25 C1 7 C, fi H 27 Cl 7 
Extraction 
1 100 104 95 
Column chromatography with silica gel/sulphuric acid 
1 100 98 nd 
2 72 76 79 
3 80 99 110 
Adsorption chromatography with Florisil 
1 95 98 90 
2 77 81 76 
3 71 71 69 
Total clean-up (matrix: sun flower oil) 
1 66 68 66 
2 89 98 95 
Total clean-up (matrix: mackerel muscle tissue) 
1 57 60 85 
Ci7H 29 Cl 
7 
97 
na 
71 
82 
na 
na 
na 
70 
92 
83 
Experiment 
Relative recoveries sPCAs [%] 
C,,H, 8 C1 6 
CqH, 7 C1 7 
C1 „-fra/i.s-chlordane 
Total clean-up (matrix: mackerel muscle tissue) 
1 101 
100 
99 
2 
99 
97 
119 
3 
84 
94 
72 
4 
89 
103 
80 
5 
76 
98 
71 
6 
67 
77 
75 
na: not analysed; nd: not determined. 
Similar recovery results were obtained for the extraction and clean-up procedure of 
sediments as Table 22 summarises. The recoveries of s- and mPCA as well as the 
internal standard 1 ’C i o-/ran.s-ch lordanc were well within the acceptation criteria for ultra 
trace methods. Recoveries were also tested with North Sea sediments containing PC As 
levels below the detection limits. 100 ng/g sediment of sPCA (63 % Cl) and 100 ng 
mPCA (57 % Cl) were added. The recoveries of four parallels were: 
13 Cio-trans-chlordane: 
78 ± 8 % 
CnH 17 Cl 7 : 
96 ± 7 % 
Ci 2 H 19 Cl 7 : 
88 ± 8 % 
Ci 4 H 23 Cl 7 : 
74 ± 3 %