Animal feeding stuffs - Methods of sampling and analysis - Performance criteria for single laboratory validated and ring-trial validated methods of analysis for the determination of mycotoxins

Abstract A single-laboratory validation (SLV) is presented for the simultaneous determination of 10 ultratrace elements (UTEs) including aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), molybdenum (Mo), lead (Pb), selenium (Se), and tin (Sn) in infant formulas, adult nutritionals, and milk based products by inductively coupled plasma (ICP)/MS after acidic pressure digestion. This robust and routine multielemental method is based on several official methods with modifications of sample preparation using either microwave digestion or high pressure ashing and of analytical conditions using ICP/MS with collision cell technology. This SLV fulfills AOAC method performance criteria in terms of linearity, specificity, sensitivity, precision, and accuracy and fully answers most international regulation limits for trace contaminants and/or recommended nutrient levels established for 10 UTEs in targeted matrixes.

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Determination of Aflatoxins and Ochratoxin A in Traditional Turkish Cereal-Based Fermented Food by Multi-Affinity Column Cleanup and LC Fluorescence Detection: Single-Laboratory Validation

Journal of AOAC International ◽

10.5740/jaoacint.17-0490 ◽

2019 ◽

Vol 102 (1) ◽

pp. 156-163 ◽

Cited By ~ 2

Author(s):

Tugrul Kaymak ◽

Ercan Koca ◽

Mustafa Atak ◽

Ercan Sarikaya ◽

Joerg Stroka

Keyword(s):

Ochratoxin A ◽

Fluorescence Detection ◽

Performance Criteria ◽

Immunoaffinity Column ◽

Method Performance ◽

Column Method ◽

Relative Standard ◽

Varied Composition ◽

Single Laboratory

Abstract Background: Tarhana is a traditional fermented, sun-dried Turkish food containing yogurt and cereals. There are several potential sources of mycotoxins in tarhana, such as contamination of ingredients or formation during preparation, when water activity is suitable for fungal growth and may lead to mycotoxin production during fermentation or subsequent sun-drying. Objective: To optimize an immunoaffinity column method and carry out single-laboratory validation for the determination of aflatoxins B1, B2, G1, and G2 together with ochratoxin A (OTA) in tarhana. Method: A homogenized sample was extracted with methanol–acetonitrile–water (25 + 25 + 50) using a high-speed blender. The sample extract was filtered, diluted with phosphate buffered saline (PBS) solution, and applied to a multi-immunoaffinity column (AFLAOCHRA PREP®). Aflatoxins and OTA were removed with neat methanol and then directly analyzed by reverse-phase LC with fluorescence detection using post-column bromination (Kobra® Cell). Results: Test portions of blank tarhana were spiked with a mixture of total aflatoxins and OTA to give levels ranging from 2.5 to 10.0 and 1.5 to 6.0 μg/kg, respectively. Recoveries for total aflatoxins and OTA ranged from 82 to 93 and 78 to 94%, respectively, for spiked samples. Based on results for spiked tarhana (30 replicates, each at three levels), the relative standard deviation for repeatability ranged from 1.4 to 7.2 and 3.6 to 7.7% for total aflatoxins and OTA, respectively. Conclusions: The performance characteristics for recovery, repeatability, and sensitivity have demonstrated that the method meets method performance criteria for use for official purposes. The method was demonstrated as being applicable to naturally contaminated samples of tarhana of varied composition obtained from local markets in Turkey. Highlights: This is the first immunoaffinity column method for simultaneous analysis of aflatoxins and OTA in traditional Turkish food (tarhana). Suitability was demonstrated by single-laboratory validation for official purposes in Turkey. The method was demonstrated as suitable for naturally contaminated samples of tarhana of varied composition.

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Colorimetric Alpha-Amylase, Falling Number, and Amylograph Assays of Sprouted Wheat: Collaborative Study

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/64.5.1243 ◽

1981 ◽

Vol 64 (5) ◽

pp. 1243-1251

Author(s):

Paul R Mathewson ◽

Charles H Fahrenholz ◽

Gordon D Booth ◽

Byron S Miller ◽

Yeshajahu Pomeranz ◽

...

Keyword(s):

Collaborative Study ◽

Primary Source ◽

The Other ◽

Alpha Amylase ◽

Falling Number ◽

Methods Of Analysis ◽

Colorimetric Test ◽

Single Laboratory ◽

Source Of Error

Abstract Results are reported of a collaborative study on the determination of sprout damage in wheat. Methods of analysis included falling number, amylograph, and a colorimetric α-amylase assay. Data for the 3 methods were linearly interrelated. Primary source of error for each method was lack of agreement among collaborators. The 3 tests adequately differentiated among sprout damage levels within a single laboratory. The colorimetric test was the most sensitive to change in α-amylase content and appeared to have greater potential for standardization than the other 2 methods

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Determination of Withanolides in Withania somnifera by Liquid Chromatography: Single-Laboratory Validation, First Action 2015.17

Journal of AOAC International ◽

10.5740/jaoacint.16-0202 ◽

2016 ◽

Vol 99 (6) ◽

pp. 1444-1458 ◽

Cited By ~ 2

Author(s):

Rojison Koshy ◽

Mayachari Shivanand Anand ◽

Balasubramanian Murali ◽

Sharon L Brunelle

Keyword(s):

Withania Somnifera ◽

Raw Material ◽

Performance Criteria ◽

Method Performance ◽

Performance Requirement ◽

Expert Review ◽

Withanolide A ◽

Expert Review Panel ◽

Single Laboratory

Abstract An LC method was developed and validated in 2007 for analyzing Withania somnifera raw material (root) and dried extracts for withanolide content, including withanoside IV, withanoside V, withaferin A, 12-deoxywithastromonolide, withanolide A, and withanolide B. The method involved the extraction of the analytes with methanol, their subsequent filtration, and then analysis on a C18 column with an acetonitrile gradient and UV detection. Single-laboratory validation yielded linearity generally in the range of 20 to 200 μg/mL for each analyte, with a repeatability precision of RSD < 3% in most cases, and recovery in the range of 90 to 105%. These results compare well with the performance criteria recently detailed in AOAC Standard Method Performance Requirement 2015.007. The method was shown to be rugged with respect to different analysts, equipment, and days of analysis, and the sample solution was shown to be stable for 24 h at room temperature after extraction. The method was reviewed by the AOAC Expert Review Panel on Dietary Supplements (Set 2 Ingredients) and approved for First Action Official MethodSM status.

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