67

Therefore,  this  study  investigated,  if  an  interpolation  was  permissible  of  the  dependence
of  the  total  response  factor  on  the  degree  of  chlorination  (Reth  et  al.,  2005).  The  total
response  factor  and  chlorine  content  of  a  PCA  mixture  are  calculated  as  follows:

1.  Determination  of  total  PCA  signal  area  from  the  mass  chromatograms  of  the  congener  groups  i:
„  ,  .  ,  ^  ^  area  ¡(congener  group)
Relative  total  CP  area  =  X  /  x  (1)

area

¡(ISTD)

The  equal  amount  of  internal  standard  in  sample  and  reference  eliminates  its  quantity.
2.  The  total  response  factor  is  calculated  as:

Total  response  factor  (PCA  mixture)
3.  The  chlorine  content  is  defined  as:

rei.  total  PCA  area  (Std.)
amount  PCA  (Std.)

(2)

Chlorine  content  (PCA  mixt.)  =  ^

rel.  area  (cong.  group  ¡)  •  chlorine  content  (cong.  group  ¡)

rel.  total  PCA  area

(3)

The  relation  between  the  total  response  factor  and  the  chlorine  content  was  established
with  seven  sPCA-mixtures  from  different  manufacturers  (degree  of  chlorination  51-69
  %)  and  nine  mPCA  (54-58  %)  from  ICI  (UK).  A  linear  correlation  was  found  (see
Figure  7).  It  allowed  to  determine  the  total  response  factor  of  a  PCA-mixture  or  of  the
PCA  content  of  a  sample  after  the  determination  of  the  chlorine  content  according  to
equation  (4):
Total  response  factor  (sample  PCAs)  =  a  ■  x  +  b  (4)
a:  slop;  b:  intercept;  x:  determined  chlorine  content

This  total  response  factor  is  then  used  to  calculate  the  total  PCA  amount  of  a  sample:

PCA  amount  (sample)=relative

  total  area  (sample)

total  response  factor  (calculated  for  the  sample)

(5)