Aflatoxin M1 and ochratoxin A in human milk in Ribeirão Preto-SP, Brazil

The objective of this study was to determine the extent of aflatoxin M1 (AFM1) and ochratoxin A (OTA) contamination in human breast milk in the city of Ribeirão Preto, São Paulo State, Brazil. During 2012, 100 samples of human milk were collected at the local Human Milk Bank. The method comprised, immunoaffinity column purification and isolation, liquid chromatography separation and fluorescence detection. The average percentage recoveries of AFM1 and OTA spiked at 20 and 50 ng/L in control human milk were 78.1 ± 11.7% and 73.7 ± 9.6%, respectively. The average relative standard deviations of AFM1 and OTA spiked at the same levels were 11.7 and 9.6% respectively. The limits of detection was 0.3 ng/L for AFM1 and OTA. The limit of determination was 0.8 ng/L for both mycotoxins. This method was used to analyze 100 human milk samples, of which, two samples were found to contain AFM1 at level greater than 0.3 ng/L. OTA was detected in 66 samples (66%), wherein 32 were above the limit of detection and 34 were in the range of from 0.8 to 21 ng/L. Results of our study indicate that breast-fed Brazilian infants had only an insignificant exposure to AFM1 and OTA.