Environmental Engineering Reference
In-Depth Information
Currently, algal toxins or red tide toxins produced during algal blooms in lakes,
estuaries and oceans are responsible for adverse effects, including the increasing
incidence of loss of phytoplankton competitor motility, inhibition of photosynthe-
sis and of enzymes, membrane damage, large fish kills, shellfish poisoning, deaths
of livestock and wildlife, as well as illness and death in humans associated with
the consumption of contaminated shellfish (Richardson
2007
; Prince et al.
2008
;
Negri et al.
1995
; Landsberg
2002
; Legrand et al.
2003
; Llewellyn
2006
; Etheridge
2010
). It has been shown that saxitoxin and its analogues are the only neurotoxins
identified in
Anabaena circinalis
from the Murray Darling River. There an exten-
sive
A. circinalis
bloom in 1991 resulted in the death of over 1600 stock (Humpage
et al.
1994
; Bowling and Baker
1996
; Steffensen et al.
1999
). The mechanisms
behind the effects of harmful algal blooms on organisms will be discussed in chap-
ter
“
Photosynthesis in Nature: A New Look
”
. Finally, microorganisms are respon-
sible for outbreaks of waterborne illness that have killed millions of people over
the last few decades all over the world (Richardson and Ternes
2011
).
8.3 Methodologies and Techniques of Emerging
Contaminants (Pharmaceuticals and Personal
Care Products) Detection
The liquid chromatography-tandem mass spectrometry (LC-MS/MS) screen-
ing method described here has been developed to target 23 pharmaceuticals and
2 metabolites with differing physicochemical properties in fish tissue by Ramirez
and his colleagues (Ramirez et al.
2007
). In this method, analysis of pharmaceuti-
cals and their metabolites in fish tissue is conducted using reversed-phase separa-
tion of target compounds with a C18 column and a nonlinear gradient, consisting
of 0.1 % (v/v) formic acid and methanol. A 1:1 mixture of 0.1 M aqueous acetic
acid (pH 4) and methanol is identified as optimal, resulting in extraction recoveries
for 24 of 25 compounds exceeding 60 % among 10 solvents tested. Eluted ana-
lytes are then introduced into the mass analyzer using positive or negative electro-
spray ionization. Note that moderate-polarity solvents are generally observed to be
most effective at removing target analytes from tissue.
Sample collection and preservation
(Ramirez et al.
2007
): Fish (
Lepomis
sp.)
were sampled from Pecan Creek (impacted by pharmaceuticals) and Clear Creek
(not impacted by contaminants) streams to serve as test and reference specimens,
respectively. Lateral fillets were dissected from fish collected at both sites and
homogenized using a Tissuemiser (Fisher Scientific, Fair Lawn, NJ) set to rotate
at 30,000 rpm. Pecan creek homogenates were stored individually, while Clear
Creek homogenates were composited into a single sample. All tissues were stored
at
−
20 °C prior to analysis.
Preparation of analytical sample
(Ramirez et al.
2007
): Approximately
1.0 g of tissue was combined with 8 mL of extraction solvent [a 1:1 mixture of
