Environmental Engineering Reference
In-Depth Information
If an organophosphorus or carbamate compound is present in the sample, it will inhibit AChE and
therefore the colour formed will be less intense or absent, depending on the concentration present
in the sample. As a built-in quality control system, a 'negative control' sample is provided which
should develop a dark yellow colour as an indication that the sample does not contain OP or CM.
If it does not do so, this means the 'system' is not functioning correctly or the reagents have been
contaminated. The detection limit for various pesticides differs, depending on how well they inhibit
AChE. The sensitivity of the Abraxis kit to carbofuran is 1.2 parts per billion (ppb), while the sensi-
tivity for other carbamates varies depending on the compound.
As far as we are aware, these test kits have not been validated in tropical environments. Assays
performed outside may need to be done away from direct sunlight and at 'reasonable' temperatures,
i.e., not at > 40ºC. Reagents must often be stored at a certain temperature, which can certainly be a
constraint under some fi eld situations. Likewise, kits often have a shelf life, and as such must be used
within a certain timeframe. Finally, depending on the nature of the work, positive results may still
require specifi c confi rmation and quantitation using more advanced techniques.
1.6 Conclusions
This chapter described the chemical properties of carbofuran (contrasting these with structurally
similar compounds that could interfere with analyses) and the environmental fate of the compound.
Its manufacture and formulation was also detailed, and a signifi cant proportion of this chapter was
devoted to a comparison of the principles of the instruments and techniques typically used to analyse
samples for residues of carbofuran and related compounds. In acknowledgement of the different
analytical capacity available in developing and developed nations, we have collated an extensive
analytical reference list regarding the detection of carbofuran in a variety of environmental samples.
The reference list is available from the editor (through the publisher), upon request.
The next chapter discusses the toxicity of carbofuran to birds and mammals. It provides values
that can be incorporated into risk assessments and outlines the signs, symptoms and potential treat-
ment options available for wildlife found to have been poisoned by carbofuran.
Acknowledgements
We thank Dietmar Knopp, Katalin Vitar and Fernando Rubio (of Abraxis LLC) for comments made
to earlier versions of this chapter in addition to the Shimadzu Corporation and PerkinElmer, Inc. for
permission to use the photographs.
References
Budavari, S. (ed.) (1989)
The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals
. New
Jersey: Merck and Co., Inc.
Fodor-Csorba, K. (1998) Pesticides in environmental samples.
Advanced chromatographic and elec-
tromigration methods in biosciences
. Deyl, Z., Mikšik, I., Tagliaro, F. and Tesaˇová, E. (eds). Elsevier
Science.
Grob, R.L. and Barry, E.F. (1995)
Modern Practice of Gas Chromatography
. Third edition, New York:
John Wiley & Sons, Inc.
Harris, D.C. (2007)
Quantitative Chemical Analysis
. Seventh edition, New York: W.H. Freeman and
Company.
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