scholarly journals Interlaboratory comparison for determination of ochratoxin A by ELISA in maize (running title: Determination of ochratoxin A in maize)

2013 ◽  
pp. 77-84
Author(s):  
Sandra Jaksic ◽  
Igor Jajic ◽  
Ksenija Nesic ◽  
Igor Stojanov ◽  
Milica Zivkov-Balos ◽  
...  
Keyword(s):  
High Pressure ◽  
Ochratoxin A ◽  
Interlaboratory Comparison ◽  
Fluorescence Detector ◽  
Elisa Kit ◽  
Proficiency Testing Schemes ◽  
Z Scores ◽  
Layer Chromatography ◽  
Selection Of

Participation in interlaboratory comparison and proficiency testing schemes is important for laboratories to control the work quality. In this study, a sample of naturally contaminated maize was analyzed for the content of ochratoxin A (OTA) in three laboratories in Serbia. Participating laboratories used enzymatic immunoaffinity method (ELISA) for the determination of OTA and selection of the ELISA kit was free. Between-laboratory precision was acceptable as evidenced by Cochran?s C test. Moreover, z-scores for all three laboratories were z < ? 2, which is considered acceptable. Used OTA confirmation methods were thin-layer chromatography (TLC) and high-pressure liquid chromatography (HPLC), with fluorescence detector. The results of different methods were comparable.

Citrus Artifact Interference in Aflatoxin M1 Determination in Milk

1981 ◽  
Vol 64 (6) ◽  
pp. 1383-1385
Author(s):  
Ralph L Price ◽  
Karen V Jorgensen ◽  
Michael Billotte
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Dairy Cows ◽  
Aflatoxin M1 ◽  
Proper Selection ◽  
False Positive Test ◽  
Citrus Waste ◽  
Layer Chromatography ◽  
Selection Of

Abstract Dried citrus waste was fed to dairy cows, their milk was extracted, and aflatoxin M1 was quantitated by using both high pressure liquid chromatography (HPLC) and thin layer chromatography (TLC). Results indicate that a compound from the citrus waste, which is excreted into the milk, interferes with the HPLC determination of aflatoxin M1 in milk and causes a false positive test. This interference can be overcome by using TLC with proper selection of developing solvents.

scholarly journals Interlaboratory Comparison for the Determination of Five Residual Organochlorine Pesticides in Ginseng Root Samples by Gas Chromatography

2007 ◽  
Vol 90 (4) ◽  
pp. 1133-1141 ◽  
Author(s):  
Mei-Fung Kong ◽  
Serena Chan ◽  
Yiu-Chung Wong ◽  
Siu-Kay Wong ◽  
Della Wai-Mei Sin
Keyword(s):  
Measurement Uncertainty ◽  
Organochlorine Pesticides ◽  
Interlaboratory Comparison ◽  
Analytical Data ◽  
Quality Criterion ◽  
Asia Pacific ◽  
Ginseng Root ◽  
Mean Values ◽  
Z Scores

Abstract An interlaboratory comparison study for the determination of 5 residual organochlorine pesticides (hexachlorobenzene and 4 hexachlorocyclohexane isomers) in ginseng root was performed. This program [Asia Pacific Laboratory Accreditation Cooperation (APLAC) T049] was the first of its kind for an herbal matrix and involved the participation of 70 laboratories from 26 countries worldwide. Consensus mean values were computed statistically from the reported results, which were eventually used to assess the performance of individual laboratories in terms of the z-scores. The distribution of analytical data was found to be widespread, with standard deviation ranging from 43.9 to 55.9%, and the result patterns obtained were similar to those residue pesticide programs using other matrixes. Although the estimation of measurement uncertainty is a crucial requirement for all quantitative tests for laboratories that meet the requirements of International Organization for Standardization/International Electrotechnical Commisssion (ISO/IEC) 17025, some laboratories in this program had difficulties and showed unfamiliarity with respect to that quality criterion. It was recommended that laboratories review and rectify the situation promptly so that they would have a better understanding of measurement uncertainty or the test service provided.

Method for the Detection and Estimation of Ochratoxin A in Some Cereal Products

1967 ◽  
Vol 50 (2) ◽  
pp. 366-370
Author(s):  
P M Scott ◽  
T B Hand
Keyword(s):  
Ochratoxin A ◽  
Aqueous Methanol ◽  
Whole Wheat Flour ◽  
Cereal Products ◽  
Whole Wheat ◽  
Sample Extract ◽  
Final Sample ◽  
Aoac Method ◽  
Layer Chromatography

Abstract A method for the detection and semiquantitative estimation of ochratoxin A in flour and other cereal products is described which can be used in conjunction with analysis of the foodstuff for aflatoxins. The sample is extracted with aqueous methanol and n-hexane and the toxin is partitioned on a Celite column, as in the AOAC method for determination of aflatoxins in peanut products. Ochratoxin A is separated by thin layer chromatography and estimated by the intensity of fluorescence compared with that of a reference standard. By this procedure, 0.01 μg ochratoxin A can be detected in 10 μl final sample extract, corresponding to a detection limit of about 25 μg/kg cereal foodstuff. The method is applicable to whole wheat flour, corn meal, barley cereal, and rice cereal. Recoveries of 80—100% of added ochratoxin A were obtained

Determination of Zearalenone in Corn by High Pressure Liquid Chromatography and Fluorescence Detection

1978 ◽  
Vol 61 (5) ◽  
pp. 1058-1062
Author(s):  
George M Ware ◽  
Charles W Thorpe
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Fluorescence Detection ◽  
Hplc Analysis ◽  
Fluorescence Detector ◽  
Reverse Phase

Abstract A method is reported for determining zearalenone in corn at levels as low as 10 ng/g. Samples are extracted with chloroform-water and cleaned up by liquid-liquid chromatography, and the zearalenone is detected by a fluorescence detector after separation by reverse phase high pressure liquid chromatography (HPLC). Recoveries of zearalenone added to corn at levels from 10 to 200 ng/g averaged greater than 89%. In addition, a confirmation procedure is described which involves sequential HPLC analysis of the sample and a zearalenone standard, using 4 different excitation wavelengths and comparing fluorescence responses obtained. This method was successfully applied to the analysis of 11 samples of cornmeal; zearalenone was detected in 9 of the samples at levels from 11 to 69 ng/g.

Determination of Ochratoxin A in Capsicum spp. (Paprika and Chili) by Immunoaffinity Column Cleanup and Liquid Chromatography: Collaborative Study

2014 ◽  
Vol 97 (3) ◽  
pp. 876-883 ◽  
Author(s):  
Zoltan Kunsagi ◽  
Joerg Stroka ◽  
E Abilleira ◽  
P Bastijns ◽  
M Berger ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Collaborative Study ◽  
Immunoaffinity Column ◽  
Fluorescence Detector ◽  
International Union ◽  
Eu Member States ◽  
Rp Hplc ◽  
Official Control ◽  
Capsicum Spp

Abstract A method validation study for the determination of ochratoxin A in Capsicum spp. (paprika and chili) was conducted according to the International Union of Pure and Applied Chemistry harmonized protocol. The method is based on the extraction of samples with aqueous methanol, followed by an immunoaffinity column cleanup. The determination is carried out by RP-HPLC coupled with a fluorescence detector. The study involved 21 participants representing a cross-section of research, private, and official control laboratories from 14 European Union (EU) Member States and Singapore. Mean recoveries reported ranged from 83.7 to 87.5%. The RSD for repeatability (RSDr) ranged from 1.7 to 14.3%. The RSD for reproducibility (RSDR) ranged from 9.1 to 27.5%, reflecting HorRat values from 0.4 to 1.3 according to the Horwitz function modified by Thompson. The correction for recovery of results from naturally contaminated samples further improved the reproducibility of the method. The method showed acceptable within-laboratory and between-laboratory precision for each matrix, and it conforms to requirements set by current EU legislation.

High Pressure Liquid Chromatographic Determination of Xanthomegnin in Corn

1978 ◽  
Vol 61 (3) ◽  
pp. 590-592
Author(s):  
Michael E Stack ◽  
Nathan L Brown ◽  
Robert M Eppley
Keyword(s):  
High Pressure ◽  
Silica Gel ◽  
Chromatographic Determination ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatograph ◽  
High Pressure Liquid Chromatograph ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Layer Chromatography

Abstract A method is described for the detection and quantitative analysis of xanthomegnin in corn samples. Initial extraction with CHCI3 in the presence of 0.5M H3PO4 is followed by additional purification using silica gel column chromatography. A high pressure liquid chromatograph equipped with a microparticle silica gel column and a 405 nm absorbance detector is used for detection and quantitation of the xanthomegnin. The identity of xanthomegnin is confirmed by thin layer chromatography on silica gel plates developed with benzenemethanol- acetic acid (90-(-5+5). The recovery of xanthomegnin added to corn samples at levels of 0.75–9.6 mg/kg averaged 41% with a coefficient of variation of 25%.

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