Page 101 - FoodFocusThailand No.222 September 2024

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antibody-enzyme conjugate called “direct non- interferences. This technique relies on the specificity of antibodies
competitive ELISA”. Alternatively, aflatoxin in the to antigens, which in this case is aflatoxin contained in a plastic
sample may bind to a primary antibody, which is column that captures aflatoxin in the extraction solution. The
then connected to a secondary antibody linked to conditions, such as pH or solvent polarity, are then adjusted to
an enzyme called “indirect non-competitive ELISA”. elute the aflatoxin. This technique not only purifies aflatoxins but
When a substrate that specifically reacts with the can also concentrate them for further analysis.
enzyme is added, a color change occurs, and the
amount of toxin can be quantified based on the color
intensity. While the competitive assay, aflatoxin in More Information Service Info C017
the sample competes with enzyme-labeled aflatoxin
for binding to the antibody. If the sample contains a
high level of aflatoxin, enzyme-labeled aflatoxin will เอกสารอ้างอิง / References
have a decreased binding for the antibody; therefore, ณััฐสิิทธิ์ิ� ตัันสิกุุล, กุมลชััย ตัรงวานิชันาม, ปารียา อุุดมกุุศลศรี และศศิธิ์ร ลิ�มสิุวรรณั.
color intensity is inversely proportional to the amount 2557. กุารปนเป้�อุนสิารพิิษอุะฟลาทอุกุซิินและอุอุคราทอุกุซิิน เอุ ในอุาหาร
of aflatoxin in the sample. However, this technique สิัตัว์เลี�ยงในประเทศไทย. สิัตัวแพิทย์มหานคร วารสิาร. 9(1): 1-9.
Muscarella, M., Lammarino, M., Nardiello, D., Magro, S., Palermo, C.,
may face issues such as over- or under-estimation Centonze, D. and Palermo, D. 2009. Validation of a confirmatory
of the toxin concentration due to matrix interference analytical method for contaminating aflatoxin B1, B2, G1 and G2 in
or cross-reactions with other components in the food and feed materials by HPLC with on-line photochemical derivat
ization and fluorescence detection. Food Additives and Contaminants:
sample. Part A. 26(10): 1402-1410.
2. Quantitative Analysis Pittet, A. 2005. Modern methods and trends in mycotoxin analysis.
Mitteilungen aus Lebensmitteluntersuchung und Hygiene. 96: 424-444.
Quantitative analysis can indicate the Sirhan, A.Y., Tan, G.H., Al-Shunnaq, A. ,Abdulrauf, L. and Wong, R.C.S.
concentration of toxins present in a sample. 2014. QuEChERS-HPLC method for aflatoxin detection of domestic
Generally, chromatography techniques are used, and imported feed in Jordan. Journal of Liquid Chromatography and
Related Technologies. 37: 321-342.
which rely on the differential distribution of substances Zheng, M.Z., Richard, J.L. and Binder, J. 2006. A review of rapid
in two phases which are the mobile phase and the methods for the analysis of mycotoxin. Mycopathologia. 161:261-273.
stationary phase. Especially, High-Performance
Liquid Chromatography (HPLC) is employed for
separating mixtures to identify and quantify
substances of interest. This technique is suitable for
detecting low levels of substances by using pressure
to move the mobile phase and the sample solution
through the stationary phase. During the movement
through the stationary phase, different substances
in the sample solution experience varying degrees
of retardation due to their interaction with the
stationary phase, leading to their separation.
Detection is performed using various detectors. For
aflatoxins, ultraviolet or fluorescence radiation is
used for detection. Sensitivity in the analysis can be
enhanced by derivatization of aflatoxins, either pre-
column derivatization, such as adding trifluoroacetic
acid, or post-column derivatization, such as adding
bromine or iodine.
Another crucial step in analyzing the quantity of
aflatoxins is extraction, which involves the clean-up
process to remove interferences during the toxin
extraction from samples. This is necessary because
aflatoxins in rice products are typically found in
meager amounts, measured in parts per billion (ppb).
Therefore, it is essential to separate aflatoxins from
the sample as much as possible. The sample must
be cleaned of contaminants and purified to ensure
efficient, accurate, and reliable analysis results.
Currently, the Immunoaffinity Column (IAC)
technique is a popular technique for removing

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