Where: 



Ais = Sum of integrated areas for internal standard; 

 Qrs = Quantity of recovery standard in ng; 

 Ars = Sum of integrated areas for recovery standard; 

 Qis = Quantity of internal standard in ng; and 

 Rf = Response factor. 



Quantification 



The PCDD/PCDF isomers were quantified by comparing the 

 sum of the two ions monitored for each class to the sum of the 

 two ions monitored for a corresponding isotopically labelled 

 congener. The octa-CDD--'--^C3^2 ^^^ used to quantify the octa-CDF. 

 Experimental relative response factors were calculated from four 

 analyses of a mixture which contained representatives of the 

 tetrachloro- through octachloro- PCDD/PCDF congener classes. 

 These response factors were included in all calculations used to 

 quantify the data. The response factors were calculated by 

 comparing the sum of the two ions monitored for each congener 

 class to the sum of the two ions monitored for the corresponding 

 internal standard. The experimental response factors were: 



Congener Class Response Factor 



Tetra-CDD 



0.91 



Penta-CDD 



1.0 



Hexa-CDD 



0.84 



Hepta-CDD 



0.91 



Octa-CDD 



0.89 



Tetra-CDF 



0.92 



Penta-CDF 



0.92 



Hexa-CDF 



0.85 



Hepta-CDF 



0.93 



Octa-CDF 



0.89 



The formula used for quantifying the PCDD/PCDF isomers 

 was: 



Concentration (ng/g) = Ac x Qis 



Ais X W X Rf 



