47

Oil  Spill  identification  -  Round  Robin  20045

4.Conclusions

Table  4  gives  a  summary  of  the  results  of  all  labs.  Because  the  source
of  the  spill  samples  is  known,  it  can  be  concluded,  that  almost  all  labs
have  drawn  the  right  conclusion.  Cedre  and  LASEM  have  both
mentioned  problems  in  detecting  the  biomarkers  and  a  higher
variability  of  the  ratios.  Petrobas  joins  the  round  robin  for  the  first  time
and  reports  good  analyses.  But  interpretation  seems  to  be  focused  on
similarities  instead  of  differences.

Participants

Methods

Results

FID

MS

S  I-  E  I

S  I  -  E  II

S  II  -  E  I

S  II  -  E  II

BMM

X

X

+

+

----





X

----









X

----









X

X

+  +

+  +

----





X

X

+  +

+

----





X

X

+  +

+

----





X

+  +

+  +

----





X

X

+  +

+  +

+  +

+  +

RIZA

X

X

+  +

+  +

----





X

X

+  +

+  +

----





X

X

+  +

+

----





X

+  +

+  +

-

-

--Significant

  differences  between  the  samples  have  been  found.

+  +

No  significant  differences  between  the  samples  have  been  found.

-  and  +

Conclusions  are  Indicated  to  be  less  certain.

Table  4
Summary  of  the  results  of  the
participants.

The  table  does  not  show  the  large  differences  found  in  the  reports  how
to  analyze  and  assess  the  results.  It  would  be  good  to  come  to  a  more
common  approach  in  dealing  with  oil  spill  samples.
On  the  CD  versions  of  Part  I  (Sampling)  and  Part  II  (analytic  and
interpretation),  as  send  to  CEN  for  comments,  are  available  for  the
participants.  The  guidelines  are  the  result  of  several  years  of  discussion
how  to  handle  oil  spill  samples.  Hopefully  this  effort  will  lead  a  more
common  method  for  all  labs.