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Research article - Peer-reviewed, 2021

Improved Sample Selection and Preparation Methods for Sampling Plans Used to Facilitate Rapid and Reliable Estimation of Aflatoxin in Chicken Feed

Kibugu, James; Mdachi, Raymond; Munga, Leonard; Mburu, David; Whitaker, Thomas; Huynh, Thu P.; Grace, Delia; Lindahl, Johanna F.


Aflatoxin B1 (AFB1), a toxic fungal metabolite associated with human and animal diseases, is a natural contaminant encountered in agricultural commodities, food and feed. Heterogeneity of AFB1 makes risk estimation a challenge. To overcome this, novel sample selection, preparation and extraction steps were designed for representative sampling of chicken feed. Accuracy, precision, limits of detection and quantification, linearity, robustness and ruggedness were used as performance criteria to validate this modification and Horwitz function for evaluating precision. A modified sampling protocol that ensured representativeness is documented, including sample selection, sampling tools, random procedures, minimum size of field-collected aggregate samples (primary sampling), procedures for mass reduction to 2 kg laboratory (secondary sampling), 25 g test portion (tertiary sampling) and 1.3 g analytical samples (quaternary sampling). The improved coning and quartering procedure described herein (for secondary and tertiary sampling) has acceptable precision, with a Horwitz ratio (HorRat = 0.3) suitable for splitting of 25 g feed aliquots from laboratory samples (tertiary sampling). The water slurring innovation (quaternary sampling) increased aflatoxin extraction efficiency to 95.1% through reduction of both bias (-4.95) and variability of recovery (1.2-1.4) and improved both intra-laboratory precision (HorRat = 1.2-1.5) and within-laboratory reproducibility (HorRat = 0.9-1.3). Optimal extraction conditions are documented. The improved procedure showed satisfactory performance, good field applicability and reduced sample analysis turnaround time.


aflatoxin; chicken feed; representative sampling; improved aflatoxin test procedure; validation

Published in

2021, volume: 13, number: 3, article number: 216
Publisher: MDPI

Authors' information

Kibugu, James
Kenyatta University
Munga, Leonard
Kenyatta University
Mdachi, Raymond
Kenyan Agricultural and Livestock Research Organization (KALRO)
Mburu, David
Kenyatta University
Whitaker, Thomas
University of North Carolina
Huynh, Thu P.
Hygiena LLC
Grace, Delia
International Livestock Research Institute (ILRI)
International Livestock Research Institute (ILRI)
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Uppsala University

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