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Kibugu J, Mdachi R, Munga L, Mburu D, Whitaker T, Huynh TP, Grace D, Lindahl JF. Improved Sample Selection and Preparation Methods for Sampling Plans Used to Facilitate Rapid and Reliable Estimation of Aflatoxin in Chicken Feed. Toxins (Basel) 2021; 13:216. [PMID: 33809813 PMCID: PMC8002447 DOI: 10.3390/toxins13030216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/03/2021] [Accepted: 03/10/2021] [Indexed: 12/22/2022] Open
Abstract
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.
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Affiliation(s)
- James Kibugu
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, P.O. Box 362, Kikuyu 00902, Kenya;
- Department of Biochemistry, Microbiology and Biotechnology, School of Pure and Applied Sciences, Kenyatta University, P.O. Box 43844, Nairobi 00100, Kenya;
| | - Raymond Mdachi
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, P.O. Box 362, Kikuyu 00902, Kenya;
| | - Leonard Munga
- Department of Animal Science, School of Agriculture and Enterprise Development, Kenyatta University, P.O. Box 43844, Nairobi 00100, Kenya;
| | - David Mburu
- Department of Biochemistry, Microbiology and Biotechnology, School of Pure and Applied Sciences, Kenyatta University, P.O. Box 43844, Nairobi 00100, Kenya;
| | - Thomas Whitaker
- Department of Biological and Agricultural Engineering, North Carolina State University, Box 7625, Raleigh, NC 27695-7625, USA;
| | | | - Delia Grace
- Department of Biosciences, International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya; (D.G.); (J.F.L.)
| | - Johanna F. Lindahl
- Department of Biosciences, International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya; (D.G.); (J.F.L.)
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
- Department of Medical Biochemistry and Microbiology, Uppsala University, 75123 Uppsala, Sweden
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