Determination of Ochratoxin A in Licorice and Licorice Extracts by High-Performance Liquid Chromatography Coupled with Fluorescence Detection: Collaborative Study

2013 ◽  
Vol 96 (2) ◽  
pp. 331-340 ◽  
Author(s):  
Donata Lerda ◽  
Massimo Ambrosio ◽  
Zoltan Kunsagi ◽  
Joerg Stroka ◽  
J Cea ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Fluorescence Detection ◽  
High Performance ◽  
Collaborative Study ◽  
Sodium Bicarbonate Solution ◽  
The United States ◽  
Licorice Root ◽  
Test Portion ◽  
Method Performance

Abstract A collaborative study was conducted to validate an analytical method for the determination of ochratoxin A (OTA) in licorice (root powder) and licorice extracts (paste and powder). Contents of OTA ranged from 26 to 141 μg/kg and from 8 to 52 μg/kg for licorice extracts and root material, respectively. For the analysis, a test portion is extracted with a mixture of methanol and aqueous sodium bicarbonate solution. The extract is filtered and diluted with phosphate-buffered saline; and OTA is purified with an immunoaffinity column containing antibodies specific to OTA. The purified extract is dried, reconstituted, and quantified by HPLC with fluorescence detection. Twenty laboratories from 13 European Union member states, Uruguay, Turkey, and the United States of America participated in this study. The study was evaluated according to internationally accepted guidelines. The method performance characteristics can be summarized as follows: over a working range of 7.7 to 141 μg/kg OTA, the mean recoveries were 87% for licorice root and 84–88% for licorice extracts; and the RSDs for reproducibility ranged from 10 to 17% and from 11 to 22% in licorice extracts and licorice root, respectively. The method was found to be fit-for-purpose and to fulfill legal requirements as set in EC Regulation No. 401/2006.

Multifunctional Column Coupled with Liquid Chromatography for Determination of Aflatoxins B1, B2, G1, and G2 in Corn, Almonds, Brazil Nuts, Peanuts, and Pistachio Nuts: Collaborative Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1512-1521 ◽  
Author(s):  
Mary W Trucksess ◽  
Michael E Stack ◽  
Stanley Nesheim ◽  
Richard H Albert ◽  
Thomas R Romer
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
The United States ◽  
Test Portion ◽  
Brazil Nuts ◽  
Pistachio Nuts ◽  
Relative Standard

Abstract An AOAC/IUPAC collaborative study was conducted to evaluate the effectiveness of a multifunctional column for the determination of aflatoxins. The test portion is extracted with acetonitrile–water (9 + 1), the extract is filtered, and the filtrate is passed through the column. The aflatoxins in the eluate are determined by reversed-phase liquid chromatography after derivatization with trifluoroacetic acid. Naturally contaminated corn, almonds, Brazil nuts, peanuts, and pistachio nuts spiked with total aflatoxins at 5,10,20, and 30 ng/g were sent to 12 collaborators in the United States, Denmark, France, Japan, and Switzerland. Eleven collaborators completed the study. Average recoveries of total aflatoxins for each spike level for the various commodities (excluding Brazil nuts at 5 ng/g) were 93,97,95, and 95%, respectively; the repeatability relative standard deviation (RSDr) ranged from 6.0 to 23.2% and the reproducibility relative standard deviation (RSDR) ranged from 12.0 to 69.4%. The multifunctional column coupled with a liquid chromatographic method for determination of aflatoxins in corn, almonds, Brazil nuts, peanuts, and pistachio nuts has been adopted first action by AOAC INTERNATIONAL.

Determination of Ochratoxin A in Cocoa Beans Using Immunoaffinity Column Cleanup with High-Performance Liquid Chromatography

2014 ◽  
Vol 97 (3) ◽  
pp. 884-888 ◽  
Author(s):  
Jillian Roberts ◽  
Ivan Chang-Yen ◽  
Frances Bekele ◽  
Isaac Bekele ◽  
Lisa Harrynanan
Keyword(s):  
Ochratoxin A ◽  
High Performance ◽  
Sodium Bicarbonate Solution ◽  
Cocoa Bean ◽  
Immunoaffinity Column ◽  
High Fat ◽  
Cocoa Beans ◽  
Solution Ph ◽  
High Degree

Abstract A method was developed and validated for the determination of ochratoxin A (OTA), a fungal metabolite, in cocoa beans of high fat content. The sample was extracted by blending with a 1% sodium bicarbonate solution (pH 10) followed by ultrasonication, and the sample was defatted by treatment with a flocculant. The defatted sample was purified using immunoaffinity column chromatography, and OTA was detected using HPLC with fluorescence detection. The method was fully optimized, validated, and quality controlled using spike recovery analyses, with recoveries of 89–105% over spiking ranges of 320–2.5 ng/g with CV of analyses generally <10% over 4 consecutive years and an LOQ of 0.66 ng/g in cocoa bean samples. This method overcomes the problems posed by the high fat contents of cocoa and chocolate samples with a high degree of reliability.

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

2019 ◽  
Vol 102 (1) ◽  
pp. 156-163 ◽  
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.

Determination of Ochratoxin A in Black and White Pepper, Nutmeg, Spice Mix, Cocoa, and Drinking Chocolate by High-Performance Liquid Chromatography Coupled with Fluorescence Detection: Collaborative Study

2017 ◽  
Vol 100 (5) ◽  
pp. 1458-1468 ◽  
Author(s):  
Elena Cubero-Leon ◽  
Katrien Bouten ◽  
Hamide Senyuva ◽  
Joerg Stroka ◽  
M Adam ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
High Performance ◽  
Collaborative Study ◽  
Reversed Phase ◽  
Fluorescence Detector ◽  
White Pepper ◽  
Black And White ◽  
Official Control ◽  
Reversed Phase Lc

Abstract A method validation study for the determination of ochratoxin A in black and white pepper (Piper spp.), nutmeg (Myristica fragrans), spice mix (blend of ginger, turmeric, pepper, nutmeg, and chili), cocoa powder, and drinking chocolate was conducted according to the International Harmonized Protocol of the International Unionof Pure and Applied Chemistry. The method is based on the extraction of samples with aqueous methanol, followed by a cleanup of the extract with an immunoaffinity column. The determination is carried out by reversed-phase LC coupled with a fluorescence detector. The study involved 25 participants representing across-section of research, private, and official control laboratories from 12 European Union (EU) MemberStates, together with Turkey and Macedonia. Mean recoveries ranged from 71 to 85% for spices and from 85to 88% for cocoa and drinking chocolate. The RSDr values ranged from 5.6 to 16.7% for spices and from 4.5 to 18.7% for cocoa and drinking chocolate. The RSDR values ranged from 9.5 to 22.6% for spices and from 13.7 to 30.7% for cocoa and drinking chocolate. The resulting Horwitz ratios ranged from 0.4 to 1 for spices and from 0.6 to 1.4 forcocoa and drinking chocolate according to the Horwitz function modified by Thompson. The method showed acceptable within-laboratory and between-laboratory precision for each matrix, and it conforms to requirements set by current EU legislation.

scholarly journals Determination of Total Fumonisins in Corn by Competitive Direct Enzyme-Linked Immunosorbent Assay: Collaborative Study

2002 ◽  
Vol 85 (2) ◽  
pp. 404-410 ◽  
Author(s):  
Chuck B Bird ◽  
Bruce Malone ◽  
Larry G Rice ◽  
P Frank Ross ◽  
Robert Eppley ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Fusarium Species ◽  
Collaborative Study ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Test Portion ◽  
Relative Standard ◽  
Standard Deviations ◽  
Different Levels

Abstract Fumonisins—mycotoxins produced by some Fusarium species—have been shown to be the causative agent of diseases in horses and other domesticated animals as well as possible carcinogens in humans. A collaborative study was conducted to evaluate the effectiveness of a competitive direct enzyme-linked immunosorbent assay (CD-ELISA) for the determination of total fumonisins (B1, B2, and B3) in corn. The test portion was extracted with methanol–water (7 + 3), filtered, diluted, and tested on the CD-ELISA. Naturally and artificially contaminated corn test portions were sent to 13 collaborators in the United States. Naturally contaminated field test portions were prepared at 3 different levels. Artificially contaminated test portions were spiked at 1.0, 3.0, and 5.0 mg/kg total fumonisins (B1, B2, and B3). Average recoveries of total fumonisins were 120, 100, and 90%, respectively. The relative standard deviations for repeatability ranged from 13.3 to 23.3% and the relative standard deviations for reproducibility ranged from 15.8 to 30.3% across all levels tested. HORRAT values, calculated for each individual sample, ranged from 1.24 to 1.94. This method demonstrated acceptable intra- and interlaboratory precision at the levels tested.

Rapid Solvent-Efficient Method for Liquid Chromatographic Determination of Ochratoxin A in Corn, Barley, and Kidney: Collaborative Study

1992 ◽  
Vol 75 (3) ◽  
pp. 481-487 ◽  
Author(s):  
Stanley Nesheim ◽  
Michael E Stack ◽  
Mary W Trucksess ◽  
Robert M Eppley ◽  
Palle Krogh
Keyword(s):  
Ochratoxin A ◽  
Collaborative Study ◽  
Kidney Tissue ◽  
Chromatographic Determination ◽  
The United States ◽  
Relative Standard ◽  
Pork Kidney ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract A joint Interlaboratory study of a rapid, solvent-efficient liquid chromatographic method for determination of ochratoxin A (OTA) in barley, corn, and pork kidney tissue was conducted by AOAC, the International Union of Pure and Applied Chemistry, and the Nordic Committee on Food Analysis In 16 laboratories in Europe, Canada, and the United States. OTA was added to barley and corn at 10,20, and 50 ng/g and to kidney at 5,10, and 20 ng/g. Duplicate test portions were prepared at 20 ng/g for corn and barley and 10 ng/g for kidney. Mean recoveries of OTA ranged from 53 to 97%. Within-laboratory relative standard deviations were 7.9,20.1, and 15.7% for barley, corn, and kidney tissue, respectively. Between-laboratories relative standard deviations were 20.7-31.7% for all concentrations of OTA In barley and corn and 68.0,41.8, and 32.7% for OTA concentrations of 5,10, and 20 ng/g, respectively, In kidney. OTA Identity was confirmed by methyl ester derivatization followed by liquid chromatography. The method has been adopted first action by AOAC as quantitative at the levels tested for OTA determination In corn and barley.

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