Geology Reference
In-Depth Information
CHAPTER 6
Environmental Organic Chemistry
CRISPIN J. HALSALL
Environmental Science Department, Lancaster University, Lancaster LA1
4YQ, UK
6.1 INTRODUCTION
Environmental Organic Chemistry (EOC) is an exciting branch of chem-
istry that has developed over the last few decades, and is probably best
known for the study into the fate and behaviour of anthropogenic (man-
made) pollutants. EOC, however, cannot be restricted to organic pollut-
ants and their behaviour, but also encompasses the myriad of organic
molecules produced by nature and their associated biogeochemistry. This
area of chemistry is coupled to the recent advances in analytical tech-
niques, particularly improvements in chromatography and the rise in
'hyphenated' techniques, such as GC-MS and LC-MS. The sensitivity of
contemporary bench-top instruments allows detection of analytes in
environmental samples, down to as low as a few picogrammes (pg)
(10
12
g) on the chromatography column. Recently, the improvements
in LC-MS technology, has resulted in affordable, yet sensitive instrumen-
tation that allows separation and detection of a mixture of polar, water-
soluble analytes. The use of LC avoids derivatisation steps of highly polar
analytes required as a pre-requisite to GC analysis. The different sources
now available to LC-MS, including atmospheric pressure photoionisation
and chemical ionisation, allows a high degree of selectivity for a wide
number of analytes of varying molecular weights, polarity and aqueous
solubility. This enables analysis of pollutant degradates and metabolites
in aqueous systems and has led to the screening of pharmaceuticals,
veterinary drugs and antibiotics in both surface and ground water.
1-3
The traditional organic chemist often works in a highly controlled
environment, where variables may be reduced to several reactants under
carefully controlled temperatures and pressures; the goal to produce a
279
