Biochemical and Histopathological Effects of Aflatoxin on ...

pigment content require a different treatment relative to those with a low
content <strong>of</strong> these components. Most <strong>of</strong> the interfering substances are <strong>of</strong>ten
soluble in the same solvents as aflatoxin, therefore, selective extraction or
extensive purification methods are required to produce pure extracts.
Therefore, the nature <strong>of</strong> the sample <strong>and</strong> properties <strong>of</strong> aflatoxin reflect the
type <strong>of</strong> extraction procedure. <strong>Aflatoxin</strong>s are soluble in slightly polar solvents
<strong>and</strong> insoluble in completely non polar solvents. Practically all aflatoxin are
extracted using mixture <strong>of</strong> organic solvents such as acetone, chlor<strong>of</strong>orm, or
methanol in combination with small amounts <strong>of</strong> water (Bullerman, 1979).
Aqueous solvents more easily penetrate hydrophilic tissues <strong>and</strong> enhance
aflatoxin extraction (Moss <strong>and</strong> Smith, 1985). Characteristic fluorescence
(Sargeant et at) 1961a) <strong>and</strong> absorption under long wave ultraviolet light
(V<strong>and</strong>er Merwe <strong>and</strong> Fourie,1963) aid detection <strong>and</strong> estimation.
3.2 Detection <strong>of</strong><strong>Aflatoxin</strong>
Analytical methods followed for the qualitative <strong>and</strong> quantitative
estimation are TLC (Visual <strong>and</strong> fluorodensitometric), HPLC, ELISA <strong>and</strong>
RIA. Visual TLC is the method <strong>of</strong> choice in the countries where other
expensive instruments <strong>and</strong> the infrastructure for immunoassays are not
available, though it is criticized for high degree <strong>of</strong> variation due to
individual's acuity. Visual TLC estimation is simple <strong>and</strong> reliable, so long as
the analyst ensures the validity <strong>of</strong> the method by acceptable recovery
experiment. Background fluorescence should be considered, whenever
fluorodensitometer is used. Immunoassays <strong>and</strong> HPLC methods, although
sensitive are not readily applicable (Shantha, 1994). As Egmond <strong>and</strong>
Wagstaffe, 1989 opined, it is more important to apply rigorous quality
assurance to the measurement procedure than to rely blindly upon
st<strong>and</strong>ardized <strong>and</strong> <strong>of</strong>ten archaic methods. Bearing this in mind, it became
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