**1. Introduction**

Aflatoxins difuranocoumarin derivatives are produced by fungi *Aspergillus flavus, Aspergil‐ lus parasiticus and Aspergillus nomius* [1] and they are part of the group of mycotoxins. From the twenty metabolites that have been formed endogenously in animals, aflatoxins B1, B2, G1 and G2 (AFB1, AFB2, AFG1 and AFG2) are the most common and the most toxic. The names of aflatoxins B1, B2, G1, and G2 are based on their florescence characteristics. Aflatoxin B1 and B2 show strong blue fluorescence under UV light, whereas aflatoxins G1 and G2 exhibit greenish yellow fluorescence [2]. All the aflatoxins have been classified as carcinogenic com‐ pounds for humans, but AFB1 has been tagged as the most dangerous, highly toxic, immu‐ nosuppressive, mutagenic, and teratogenic compound and its effects have been identified as well. Also, malabsorption syndrome and reduction in bone strength may occur due to AFs consumption. Aflatoxins not only have adverse effects on human health but also cause seri‐ ous economic losses when tons of foods have to be dropped or destroyed for being contami‐ nated with AFs.

To ensure food's safety, the maximum level of aflatoxins in food has been set by internation‐ al organizations. For each kind of aflatoxin a minimum quantity of concentration is allowed,

© 2013 Contreras-Medina et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Contreras-Medina et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

for instance, European Commission Regulation 2010/165/EC established limits of 8 and 15 µg/kg for AFB1 and total AFs respectively. Several methods have been developed to deter‐ mine AFs in foods, for instance: immunoassays techniques [3], Thin layer chromatography (TLC) [4]. High-Performance liquid chromatography (HPLC) with fluorescence detection [5]. Not long ago, analytical methods based on clean-up with immunoaffinity column and HPLC with postcolumn derivatization and fluorescence detection have gained much popu‐ larity. Even though, several works have been reported to determine AFs in foods by using these methods, only few validation studies are available which comply with certain regula‐ tions. There are immunochemical methods which are based principally on enzyme-linked immunosorbent assay (ELISA) that has a good sensitivity; speed and simplicity; however these kinds of instruments are expensive. An alternative of improving the disadvantages of the previous methods are trying to be solved by biosensors which are devices that enable identification and quantification of aflatoxins. Exists a variety of biosensors that base their performance in several principles, those are: optical, optoelectronic, electrochemical, piezo‐ electric, DNA and combined. In the same way, there are other methods not as common as the previous methods but they have a wide utility as well. The most important are those that base their principle on electrochemistry, spectroscopy and fluorescence.

**2.1. Gas Chromatography (GC)**

constitute a Gas Chromatography System.

**Figure 1.** Block diagram of a gas chromatograph.

**2.2. Liquid Chromatography (LC)**

**2.3. Thin-Layer Chromatography (TLC)**

pled with GC.

The instrumentation of gas chromatography comprises well defined components that ac‐ complish specific functions of the overall process. GC almost reaches the complete develop‐ ment of technological level in 50 years. The Figure 1 shows the principal components that

Characteristics of Mycotoxin Analysis Tools for Tomorrow

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Gas supply means to move the sample through the column; the possible gases to choice are restricted and the most commonly used are nitrogen and helium. It is also necessary to con‐ trol the gas flow because it can have impact on the separating performance. Tramps can be purchased to reduce or remove hydrocarbons and oxygen in the carrier gas. The chromato‐ graphic process starts when the sample is introduced into the column, ideally without dis‐ rupting flows in the column. Therefore, the deliberation of the sample into the column should be controlled, reproducible and rapid. The GC include an oven which is an impor‐ tant component in this process, because the vapor state must be maintained thought the GC separation, therefore, a good control of temperature must be kept. Another important com‐ ponent of the gas chromatography is the detector which has been evolved through the years. Nowadays, the mass spectrometer (MS) promises to be the most suitable method to be cou‐

The principle of liquid chromatography is the separation process which is based on the dis‐ tribution between two phases. The sample is propelled by a liquid which percolates a solid stationary phase. Thus a variety of stationary phases can be used in liquid chromatographic systems. The liquid chromatographic process and the separation of the sample may be ach‐ ieved, both, in low and high pressure systems. And the correct selection of the separation mode stationary phase and mobile phase may be straight (normal) phase, reversed phase

Thin-layer chromatography is a very commonly used technique in syntactic chemistry. This technique identifies compounds by determining the purity and progress of a reaction. Such reaction is fast and only requires a small quantity of the compounds. In TLC the mobile phase is liquid and the stationary process is a solid adsorbent. Several factors determine the

and size-exclusion (SEC) or ion-exchange (IEC) liquid chromatography respectively.

The chapter has two main proposes. First, to give general description of the most common methods used for quantifying aflatoxin concentrations. And second, to give a perspective about the tendencies in the development of systems, based on the so far used methods, which could be employed in the near future to detect and quantify aflatoxins in food.
