Proceedings of the International Cyanide Detection Testing Workshop

eview all the information is one reason I say
probably – I fi nd no fl aws with the analysis
technique. I do have concerns about the use
of sulfuric acid possibly oxidizing thiocyanate
to cyanide based on some work I did 20+
years ago. This is not likely to be an issue with
drinking water but with biological samples, it
is a concern.”
There is almost nothing in the published
scientifi c literature concerning the use of
the ISE method for detection of cyanide
associated with the digestion and distillation
of fi sh tissue samples (Dzombak et al.
2006). Consequently, Dr. Kobelski noted the
following concerns: 1) the possible oxidation
of the cyanide by sulfuric acid in the digestion
fl ask; 2) the lack of demonstration of
adequate recovery in controlled experiments
using spiked tissue samples; 3) that unexposed
MAF might have background levels; 4) that
the kinetics of cyanide might be too fast for
cyanide to be detectable at points of export
or import. Since there is no published data
available, he proposed that research should be
conducted to evaluate these questions.
Need for a Field Test For Ports of Entry
In USA
The U.S. Fish and Wildlife Service (USFWS)
agents present at the Cyanide Detection
Workshop expressed the need for a reliable,
rapid, easy to use fi eld test that could be used
to detect cyanide or its byproducts at US ports
of entry such as Los Angeles, San Francisco,
Miami, and New York (where most marine
ornamental fi shes are imported). There are a
number of low-cost test kits that can measure
CN - either using colorimetric methods or
using ion selective electrodes (ISE) linked to
portable ISE meters.
The authors believe that because the CN - is
metabolized to thiocyanate anion (by the
enzyme rhodanese); it is unlikely that cyanide
54
ion would be detectable using the ASTM ISE
method in importing countries like the USA,
because of the long time delay before fi sh
reach U.S. points of entry (by air). However,
Dr. Kobelski felt that if the kinetics are slow
enough for cyanide to be retained in the fi sh
until the time of export, that it might also be
possible to detect the presence of cyanide
using the ISE method at points of import to
the U.S.A. Theoretically is should be possible
to measure SCN - in MAF because it would
be retained for a longer time period. The
advantage of measuring thiocyanate is that
appreciable concentrations of SCN - may
be found following exposure and it has a
longer half-life than CN - (Logue and Hinkens
2008).
Measuring Thiocyanate in Blood
Two research grants were obtained by Dr.
Roman Lanno at Ohio State University
(OSU) to determine the feasibility of
measuring SCN - in the blood of MAF after
they had been imported into the U.S.A.
(Lanno et al. 2002a, Lanno et al. 2002b). The
objective of the proposed research (Lanno
et al. 2002a, 2002b) was to assess whether
plasma thiocyanate (SCN - ) could be used as
a biomarker of cyanide exposure in marine
aquarium fi shes captured using the cyanide
squirt bottle technique. The objective of
the study was to be met by conducting three
experiments: i) Validate and refi ne an existing
high pressure liquid chromatography (HPLC)
technique for the determination of SCN -
in the plasma of marine aquarium fi sh, ii)
Determine the pharmacokinetics of SCN - in
a marine aquarium fi sh species exposed to
sublethal levels of waterborne cyanide, and;
iii) Determine the toxicokinetics of SCN - in
the plasma of a marine aquarium fi sh species
exposed to a pulse dose of cyanide that
simulated exposure during actual collection
on a coral reef.