new dioxin-like family ID'ed / Chlor-Alk furans

[ttweed@wildrockies.org (Tony Tweedale)]

the 3/99 Amer Chem Society meeting and their Preprints of Extended
Abstracts had a session on POPs.  A couple of the more interesting extended
abstracts:
--

Harun Parlar (Techn U., Munich): Chlorinated DIPHENOQUINOES: a new class of
dioxin isomeric compounds' (p. 184-6)

Under oxidative conditions, phenols can couple at the para position,
leading to a double quinoid system.  Apparantly after going through a
dihydroxy-biphenyl stage (as in PCBs), the oxidative conditions make the
C-to-C bond between the 2 phenol rings a double bond--somewhat more stable
and more planar (less rotation).  The alcolhol groups of the phenols also
become double bonded oxygens (esters, I thnk).  The 2,3,7,8 equivalent
positions are the 3,3,5,5 positions.  In oxidative condition tests, the
diphenoquinnes were created in the same order of magnitude as dioxins! The
paper describes a new analytical method, so I guess we can assume that they
have not been counted as PCDD/F peaks in previous analysis.
--


Y. Xu, W Z Wu et al. (INstitute Hydrobiology, Chinese Academy of Sciences;
and Institu fur Okologische Chemie)  'Source, Distribution &
Bioaccumulation of PCDD/F in Ya-Er Lake, China' (p. 175-6)

(This abstract has translation unclarity & typos)  An unamed chlor-alkali
plant on the Yangtze River that (or where) also produced pesticides until
'83 had some wastes analyzed, and sediment cores were taken in this lake on
the river, as well as liver samples from fish & fowl.  It *reads like* it
is the sludge from the graphite electrolytic anode that has 200,000 ng/kg
(ppt, or 0.3 ppm) total furans (the 300,000 is twice written as '3000,000',
but in both cases immediatelly followed by a statement that "240,000 ng/kg
of which was 2,3,7,8-substituted furans", so I think they meant '300,000').
It may be they are talking about levels in the sediment cores, but I
don't think so, even tho the sediment PCDD/F levels aren't mentioned.  They
do say that only low levels (<50 ng/kg) of PCDD/F were found in the "other
four [un-named] chloralkali  product samples."  The sediment nearest the
plant did not have octafuran dominating the profile, as the other sedimet
cores did.

Anyway, more proof that chlor-alkali plants produce PCDD/F.

Tony Tweedale

Causality is a concept not subject to empirical demonstration. -David Hume
(1711-'76)

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