Enzyme‐linked immunosorbent (ELISA) determination of aflatoxin B1in peanut butter: Collaborative trial

1988 ◽  
Vol 5 (4) ◽  
pp. 601-608 ◽  
Author(s):  
David N. Mortimer ◽  
Martin J. Shepherd ◽  
John Gilbert ◽  
Colin Clark
Keyword(s):  
Peanut Butter ◽  
Collaborative Trial

Liquid Chromatographic Determination of Aflatoxin Levels in Peanut Butters Using an Immunoaffinity Column Cleanup Method: International Collaborative Trial

1991 ◽  
Vol 74 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Alan L Patey ◽  
Matthew Sharman ◽  
John Gilbert
Keyword(s):  
Peanut Butter ◽  
Chromatographic Determination ◽  
Immunoaffinity Column ◽  
Collaborative Trial ◽  
Coefficients Of Variation ◽  
Relative Standard ◽  
Cleanup Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Thirteen laboratories In 7 different countries participated in a collaborative trial to evaluate an Immunoaffinity column cleanup procedure with quantitation by fluorescence liquid chromatography (post-column derivatization) for the determination of aflatoxins In peanut butters. Participants were sent 10 randomly numbered samples of roasted peanut butter for analysis (5 pairs of undisclosed duplicates). Two of the pairs were "blank" peanut butters to which aflatoxin standards had been added; these "spiked" samples were used for recovery purposes. The other 3 pairs of samples were a nominal "blank" and 2 naturally contaminated peanut butters. A full statistical presentation of the results is given. Coefficients of variation (CVs) for the total aflatoxin determinations for mean levels of 4,15, and 38 µ/kg were between 32 and 44% for the blank and 2 trial samples. Recovery levels for the 2 spiked samples were 51-67%, with aflatoxin B1 recovery of 60%. Relative standard deviations for method repeatability (RSDr) and reproducibility (RSDR) for the 3 trial samples were 15-26% and 33-45%, respectively.

Determination of Aflatoxins in Peanut Butter, Using Two Liquid Chromatographic Methods: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 312-316
Author(s):  
Alfred D Campbell ◽  
Octave J Francis ◽  
Roberta A Beebe ◽  
Leonard Stoloff ◽  
◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Peanut Butter ◽  
Collaborative Study ◽  
Normal Phase ◽  
Phase Method ◽  
Reverse Phase ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Packed Flow Cell

Abstract Two methods for determining aflatoxins in peanut butter, one using normal phase and the other reverse phase liquid chromatography (LC), were studied by 8 and 10 collaborators, respectively. Fluorescence detection was used for the determinative step in both methods. For reverse phase LC, aflatoxins B1 and G1 were converted to B2a and G2a; for normal phase LC, a silica gel-packed flow cell was placed in the irradiating light path of the detector. The samples included spiked and naturally contaminated peanut butter with total aflatoxin levels from about 5 to 20 ng/g and controls in a balanced pair design. For the normal phase LC method, recoveries of B1, B2, G1, and G2 from spiked samples averaged 79, 92, 74, and 88%, respectively; for the reverse phase method, the recoveries were 103, 104, 89, and 163%. For the normal phase LC method, pooled repeatabilities were 20, 23, 28, and 17% for B1, B2, G1, and G2, respectively; for the reverse phase method, the repeatabilities were 19, 22, 38, and 31%. For the normal phase method, pooled reproducibilities were 34, 33, 39, and 34% for B1, B2, G1, and G2, respectively; for the reverse phase method, the reproducibilities were 32, 46, 51, and 52%. Both methods show an improved limit of detection and better within-laboratory precision over current AOAC methods; however, between-laboratory precision is no better, and the reverse phase method shows evidence of interferences being measured. For these reasons and because of no benefits of present value, neither method was submitted for adoption as official first action.

Determination of Total Aflatoxin Levels in Peanut Butter by Enzyme-Linked Immunosorbent Assay: Collaborative Study

1992 ◽  
Vol 75 (4) ◽  
pp. 693-697 ◽  
Author(s):  
Alan L Patey ◽  
Matthew Sharman ◽  
John Gilbert
Keyword(s):  
Immunosorbent Assay ◽  
Aflatoxin B1 ◽  
Peanut Butter ◽  
Collaborative Study ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Total Aflatoxin ◽  
Aflatoxin Level ◽  
Relative Standard

Abstract Laboratories in Australia, Japan, Spain, the United Kingdom, and the United States participated in a collaborative study to evaluate a commercial enzyme- linked immunosorbent assay for the determination of total aflatoxin. Collaborators were sent 10 randomly numbered samples (5 blind duplicates) of roasted peanut butter. Two pairs were "blank" peanut butters to which aflatoxin B1, B2, G1, and G2 standards had been added. The other 3 pairs of peanut butters were 1 low aflatoxin level sample and 2 naturally contaminated samples. The assay is based on indirect competition. Test samples containing (free) aflatoxin, added to aflatoxin-coated microwells, compete for specific monoclonal rat anti-aflatoxin. As the concentration of aflatoxin in the test samples increases, the amount of rat antiaflatoxin binding to the aflatoxin attached to the well decreases. After a wash step to remove unbound material, the amount of rat anti-aflatoxin bound to the well is determined by its reaction with peroxidase conjugated rabbit anti-rat globulin. Bound peroxidase activity is then determined by the addition of a substrate, whose color development is inversely proportional to the aflatoxin concentration and is measured by absorbance. Coefficients of variation (CV) for total aflatoxin concentrations, for mean levels of 9,30, and 89µg/kg, were between 28 and 37% for the low level and 2 naturally contaminated samples, which contained mainly aflatoxin B1. CVs for the spiked samples were lower (24-25%) for mean levels of 11 and 20 µg/kg; recoveries were 84 and 89%, respectively. Ranges for relative standard deviations for repeatabilty and reproducibility were 9-30% and 25-37%, respectively. The method has been adopted first action by AOAC International.

Comparison of Two Immunochemical Methods with Thin-Layer Chromatographic Methods for Determination of Aflatoxins

1990 ◽  
Vol 73 (3) ◽  
pp. 425-428
Author(s):  
Mary W Trucksess ◽  
Kathryn Young ◽  
Kevin F Donahue1 ◽  
Deborah K Morris ◽  
Ernie Lewis
Keyword(s):  
Thin Layer ◽  
Correct Response ◽  
Peanut Butter ◽  
Screening Method ◽  
Elisa Test ◽  
Poultry Feed ◽  
Enzyme Linked Immunosorbent Assay ◽  
Affinity Column ◽  
Negative Results

Abstract Three different methods were compared for the determination of total flatoxins in corn and peanuts naturally contaminated with aflatoxins and In corn, peanuts, cottonseed, peanut butter, and poultry feed spiked with aflatoxins Bi, B2, and d . The 3 methods were an enzyme-linked Immunosorbent assay (ELISA) screening test; a monoclonal antibody-affinity column-solld-phase separation method; and the AOAC official thin-layer chromatography (TLC) methods for all except poultry feed, for which Shannon's TLC method for mixed feed was used. The ELISA test is designed to provide only positive results for total aflatoxins at >20 ng/g or negative results at <20 ng/g. The affinity column separation Is coupled with either brominatlon solution fluorometry to estimate total aflatoxins or liquid chromatography (LC) to quantltate Individual aflatoxins. Fluorodensitometry was used to determine aflatoxins In commodities analyzed by the TLC methods. The LC and TLC results were In good agreement for all the analyses. The results for the affinity column using brominatlon solution fluorometry were similar except those for cottonseed, which were about 60% higher. The ELISA screening method correctly Identified naturally contaminated corn and peanut positive samples. No false positives were found for controls. The correct response for spiked corn, raw peanuts, peanut butter, and cottonseed at >20 ng aflatoxlns/g was about 90%. The correct response for spiked poultry feed at >20 ng aflatoxlns/ g was about 50%.

Evaluation of Automated Sample Preparation for Mycotoxin Analysis in Foods

2020 ◽  
Vol 103 (4) ◽  
pp. 1052-1059 ◽  
Author(s):  
Kai Zhang
Keyword(s):  
Sample Preparation ◽  
Reference Materials ◽  
Certified Reference Materials ◽  
Peanut Butter ◽  
Method Performance ◽  
Robotic Arms ◽  
Automated Sample Preparation ◽  
Sample Preparation Procedure ◽  
Mycotoxin Analysis

Abstract Background In the present study, we developed a novel automated sample preparation workflow for the determination of mycotoxins in foods. Objective This workflow integrates off-line devices such as a centrifuge, shaker, liquid and solid dispensing units into a unified platform to perform gravimetric and volumetric dispensing, capping/decapping, extraction, shaking, filtration, and centrifugation. Two robotic arms provide sample transportation without human assistance. Method Critical method performance attributes were characterized using spiked corn, milk and peanut butter containing aflatoxins, deoxynivalenol, fumonisins, ochratoxin A, HT-2 and T-2 toxins and zearalenone and certified reference materials. Prepared samples were analyzed by liquid chromatography mass spectrometry (LC-MS). Results Recoveries of spiked samples range 100–120% with RSD<20% and the majority of measured values of certified reference materials are consistent with certified values within ±20%. Within- and between-batch variabilities of QC samples range 5–9% and 7–12% respectively. Conclusions Our workflow introduces a straightforward and automated sample preparation procedure for LC-MS-based multimycotoxin analysis. Further, it demonstrates how individual sample preparation devices, that are conventionally used off-line, can be integrated together. Highlights This study shows automated sample preparation will replace manual operations and significantly increase the degree of automation and standardization for sample preparation.

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