Comparison of methods by TLC and HPTLC for determination of aflatoxin M1 in milk and B1 in eggs

Abstract

Comparação de metodologias para análise de aflatoxinas M 1 e B 1 em leite e ovos, Scussel 1. Recebido para publicação em 07/08/2001. Aceito para publicação em 11/09/2003 (000711). 2 Laboratory of Mycotoxicology, Food Science and Technology Department, Centre of Agricultural Sciences, Federal University of Santa Catarina, POBox 476, Florianópolis, SC, Brazil. Fax +55 (0) 48.331.9943, e-mail: vildes@cca.ufsc -INTRODUCTIONAflatoxin M 1 (AFM 1 ), a metabolite of aflatoxin B 1 (AFB 1 ), was first detected in milk of lactating cows that had ingested AFB 1 contaminated feed. The AFM 1 was also detected in the animals urine and faeces. As for cows, when chicken are fed with contaminated feed, AFB 1 can be transferred, to the egg, in that case, without modification on its chemical structures [1,2,7,11].Studies have indicated that the toxicity of AFM 1 is of the same order of magnitude as that of AFB 1 [2,15,16,34] and that AFM 1 is also a potent hepatocarcinogen in laboratory animals [28]. Therefore, the contamination of dairy products with AFM 1 has been recognised as a significant human health hazard, particularly for babies, since milk is their basic food and the young of most animal species is more susceptible than the adult animal to its effect. The conversion ratio of the AFB 1 ingested to the AFM 1 found in the milk is between 0.5 and 3% [4]. As far as the Regulations and maximum residue level (MRL) are concerned, the United States have declared a risk assessment for AFM 1 with an MRL in milk for human consumption of 0.5µgkg(US Food and Drug Administration Guidelines for Acceptable Levels of Aflatoxin in Food and Feed), the same for Brazil [9] and the Economic European Community (EEC) proposal on MRL of AFM 1 is 0.05µgkg -1 for milk and milk products [29,33], on the other hand, there is not legislation for AFB 1 contamination in eggs.The detection of mycotoxins often involves a combination of adsorption and fluorescence properties, being therefore, the AFM 1 and AFB 1 detected by their inherent fluorescence by thin layer chromatography (TLC), high performance thin layer chromatography (HPTLC) or high performance liquid chromatography (HPLC). The physico-chemical properties basedAflatoxinas M 1 (AFM 1 ) e B 1 (AFB 1 ) foram analisadas em leite e ovos respectivamente, por diferentes métodos oficiais da AOAC e modificações usando detecção por cromatografia em camada delgada (CCD) e CCD de alta eficiência (CCDAE). Os métodos modificados: Blanc e Romer, apresentaram-se mais apropriados para análise de AFM 1 em leite. Ambos reduziram formação de emulsão, produziram extratos limpos, sem formação de caudas. Inclusive, a precisão e acuidade aumentaram, especialmente quando a quantificação foi realizada por CCDAE. O uso de solventes ternários, no método de Blanc, foi vantajoso. Este solvente extrai AFM 1 diretamente da primeira fase (extração), deixando outros compostos na camada binária, evitando emulsão, reduzindo assim, perda da toxina. O RSD% foi muito baixo com 16 e 7%, respectivamente. Quanto ao ovo, AFB 1 e extra...

A Review: Sample Preparation and Chromatographic Technologies for Detection of Aflatoxins in Foods

“…In 2D-TLC analyses, the plate is turned 180 • after the first development and aflatoxins and matrix components are further separated in the 2nd development. The comparison of 1D-TLC and 2D-TLC for aflatoxin M 1 and B 1 in fatty foods (milk and eggs) shows that the two techniques provide comparable recoveries, but RSDs associated with 2D-TLC are much lower (7%) than that of 1D-TLC (16%), suggesting better repeatability [176]. The author emphasized that with limited separation capacity, 2D-TLC-based determinations of aflatoxin M 1 and B 1 requires in-depth sample clean-up procedures for fatty samples but the TLC analysis itself is an easy operation for inexperienced chemists and a more economical choice for labs without a budget for capital instruments such as LC.…”

Micotoxinas Em Alimentos Produzidos No Brasil

“…A ocorrência de micotoxinas em milho e produtos a base de milho tem sido reportada por vários autores, principalmente em se tratando de aflatoxina e fumonisina (Amaral et al, 2006;Kawashima & Valente soares, 2006;Sekiyama et al, 2005;Camargos et al, 2000, Fick et al, 2003, Machinski et al, 2001, Caldas & Silva, 2007.…”

A rapid FT-NIR method for estimation of aflatoxin B1 in red chili powder

“…Some of the existing methods used for AFB 1 quantification include thin layer chromatography (TLC); high performance thin layer chromatography (Scussel, 2003); high performance liquid chromatography (Gilbert, 1999;Trucksess & Pohland, 2001); immunochemical methods like ELISA (Chu, 2004); flow system coupled capillary electrophoresis (Pena et al, 2002); immunochromatographic strip (Xiulan et al, 2006). Although high performance liquid chromatography methods (HPLC) and immunoassays (ELISA) have high selectivity and are accurate offering good detection limits (0.01-0.1 ppb); it is time consuming, requiring the use of unfriendly chemicals and trained laboratory personnel (Huie, 2002;Laasonen, Harmia-Pulkkinen, Simard, Räsänen, & Vuorela, 2003).…”