HPLC determination of the total content of aflatoxins in naturally contaminated eggs in free and conjugate forms

Abstract

A study was undertaken to evaluate the total aflatoxin content in naturally contaminated eggs. Two pools of eggs from laying hens were collected after 2 and 7 days of treatment with aflatoxin B1 (AFB1). An HPLC method has been developed for the determination of AFB1, aflatoxin M1 (AFM1), aflatoxin B2a (AFB2a) and aflatoxicol (Ro) both in free form and after release from water-soluble conjugates. The bound form was cleaned up after acid hydrolysis of the aqueous phase. Eggs collected after 2 days of treatment revealed residues of AFB1, AFB2a and Ro in the organic phase, but none in the aqueous portion. After 7 days of treatment both AFB1 and its hydroxy derivative were found in the organic phase but the aqueous portion showed only hydroxylated metabolites accounting for 35% of the total aflatoxin content.

Aflatoxin residues in eggs of laying Japanese quail after long-term administration of rations containing low levels of aflatoxin B1

“…Similarly, Wolzak et al (1985) and Micco et al (1987) only observed detectable levels of AFM 1 in hens' eggs after 4 and 7 days, respectively, thus suggesting that the formation of AFM 1 is not a significant pathway during the first days of aflatoxin treatment of laying birds. However, in the present study, the concentrations of AFM 1 were in the range 0.03-0.37 mg kg À1 and the highest levels were found in eggs from treatment with 100 mg AFB 1 kg À1 , particularly after 60 days of continuous ingestion of the contaminated diet.…”

“…Extraction and quantification procedures followed 649 Aflatoxin residues in eggs of laying Japanese quail the method recommended by the Association of Official Analytical Chemists-978.15 (Scott 1990), including modifications as described by Wolzak et al (1985) and Micco et al (1987). Each lot of 32 eggs was pooled (egg white plus yolk) in a blender jar and blended 1 min at moderate speed.…”

“…The final extract was divided into two portions for determination of aflatoxins, one for AFB 1 and the other for AFM 1 , AFB 2a and AFL analysis (Micco et al 1987). Trifluoroacetic acid (TFA, 50 ml) was added to the vial containing the AFB 1 portion to convert it to AFB 2a .…”

Immunological status of the progeny of breeder hens kept on ochratoxin A (OTA)-contaminated feed

“…Residues of OTA are detected in tissues such as liver, kidneys, muscles, eggs, and plasma of OTA-fed poultry birds (Frye and Chu, 1978;Micco et al, 1987;Niemiec et al, 1994;…”

Development and Application of a Two-Phase Clean-Up System in Food Samples Prior to Fluorescence Analysis of Aflatoxins

“…The order of aflatoxin toxicity (AFB 1 >AFG 1 >AFB 2 >AFG 2 ) seems to be due to the structure of the toxin, especially the terminal furan moiety [3][4][5]. These aflatoxins are present in several commodities such as peanuts, cereals and cottonseeds, whereas aflatoxin M 1, which is just as toxic as aflatoxin B 1 [6], is most often analyzed in milk and dairy products.…”