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Oil  Spill  identification  -  Round  Robin  20045

2.12  Waterschap  Regge  en  Dinkel  (WRD)
Contact:  A  Kroeskamp

Waterschap  Regge  en  Dinkel  www.wrd.nl  is  a  local  authority
responsible  for  the  water  quality  of  an  eastern  part  of  the  Netherlands.
The  analysis  of  the  total  amount  of  mineral  oil  in  water  samples  (ISO
9377)  is  a  routine  method,  which  is  also  applied  to  identify  the  type  of
oil  in  samples  and  sometimes  to  compare  samples  in  case  of  an  oil  spill.
For  the  analysis  GC-FID  is  used.  The  analysis  with  MS,  mentioned  in  the
conclusions,  is  beyond  the  scope  of  their  lab.
Resulting  chromatograms  can  be  found  in  the  original  report.
The  results  were  received  by  letter  in  Dutch.  Page  1  and  2  contains  the
most  relevant  information  within  the  framework  of  this  report  and  has
therefore  been  translated,  see  document  Results  page  1  and  2
english.doc  on  the  CD.  The  original  document,  including  the
chromatograms,  has  been  scanned  into  document  WRD  RR2005.pdf.
=>
Comparison  of  extract  1  and  extract  2:
The  fractions  C10-C12  and  C12-C16  of  the  extracts  1  and  2  are
different  and  are  also  different  from  the  same  fractions  of  source  1
and  source  2,  so  the  contamination  of  the  canal  is  not  caused  by  one
of  the  sources  and  are  also  not  related  to  each  other.
If  the  difference  in  percentages  of  the  more  volatile  fractions  is
caused  by  evaporation  and  biological  degradation,  then  the  two
extract  samples  are  comparable  and  from  the  same  source.
Contamination  in  the  canal  is  from  source  I  or  source  II:
The  source  1  mineral  oil  percentages  in  the  “more  heavier”  fractions
after  C20  match  very  well  with  the  same  fractions  of  extract  1  and
extract  2.  (see  shading  in  table  2)
Similar  properties  of  the  oil  chromatograms  of  extract  1  and  2  en
source  1;  the  alkanes  of  fraction  C18-C26  show  an  irregular
reduction  in  peak  height.  The  peak  heights  of  the  alkanes  of  fraction
C18-C26  of  source  2  show  a  hyperbolic  pattern.
Based  on  the  above-mentioned  observations  and  results  (GC/FID)  it  is
concluded  that  source  1  is  responsible  for  the  contamination.
Because  the  properties  of  the  4  samples  don't  show  clear  differences
confirmation  with  MS  will  be  necessary.