Fitness for purpose – Ochratoxin A analytical developments

Figures & data

Table I. Official or validated methods for OTA analysis in different food matrices.

Matrix (LOQ^a, μg/kg)	Solvent extraction	Cleanup/detection^b	Official method^c (reference)
Barley, maize, wheat bran (≥25.0)	CHCl3-aq. H3PO4	Basic diatomaceous heart/TLC	AOAC 973.37 (Nesheim et al. 1973)
Green coffee (≥41.0)	CHCl3	Basic diatomaceous heart/TLC	AOAC 975.38 (Levi 1975)
Barley, maize (≥10.0)	CHCl3-aq. H3PO4; aq. NaHCO3 partition	C18/LC-FD	AOAC 991.44 (Nesheim et al. 1992)
Barley, maize, wheat bran (≥3.0)	CHCl3-aq. H3PO4; aq. NaHCO3 partition	C18/LC-FD	CEN 15141-2 (EN 15141-2 1998)
Barley, rye, wheat bran (≥2.0)	CHCl3-aq. H3PO4; aq. NaHCO3 partition	C18/LC-FD	NMKL 143 (Larsson and Moller 1996)
Wheat whole meal (≥0.4)	Toluene-HCl-MgCl2	Silica gel/LC-FD	CEN 15141-1 (Majerus et al. 1994)
Barley (≥1.3)	CH3CN-H2O	IMA/LC-FD	CEN 14132; AOAC 2000.03 (Entwisle et al. 2000)
Roasted coffee (≥1.2)	CH3OH-aq. NaHCO3	Phenylsilane + IMA/LC-FD	CEN 14132; AOAC 2000.09 (Entwisle et al. 2001)
White wine (≥0.1); beer, red wine (≥0.2)	Addn. PEG-aq. NaHCO3	IMA/LC-FD	CEN 14133; OIV 16/2001; AOAC 2001.01  (Visconti et al. 2001)
Cocoa powder (≥0.1)	aq. NaHCO3	IMA/LC-FD	CEN submitted (Brera et al. 2005)
Dried fruits (≥0.1 − ≥10.0)	CH3OH-aq. H3PO4	IMA/LC-FD	CEN submitted (MacDonald et al. 2003)
Peanut butter, maize matrices (≥0.1)	CH3CN-H2O	IMA^d/LC-FD	(Chan et al. 2004)
Cocoa beans (≥0.1)	CH3OH-aq. NaHCO3	IMA/LC-FD	(Amezqueta et al. 2004)
^aLOQ, Limit of Quantification; ^bTLC, Thin Layer Chromatography; IMA, Immunoaffinity Cleanup; LC, Liquid Chromatography; FD, Fluorescence Detector; ^cCEN, European Committee for Standardization; AOAC, Association of Analytical Chemists; NMKL, Nordic Committee on Food Analysis; OIV, Organization Internationale de la Vigne et du Vin; ^dAflaOchra™ immunoaffinity columns (Vicam Ltd, Watertown, MA, USA), suitable for simultaneous detection of aflatoxins and OTA.

Table II. FAPAS results of OTA analysis in different food matrices^a.

Report number	Matrix	Assigned OTA value (μg/kg)^b	Total number of scores^c	Number of satisfactory scores (%)^d
1731	Dried vine fruit	10.50	71	62 (87%)
1732	Barley	5.60	95	75 (79%)
1733	Green coffee	9.60	56	48 (86%)
1734	Baby food	0.89	36	33 (96%)
1735	Spices	56.10	46	36 (78%)
1736	Wine	1.80	43	42 (98%)
1737	Wheat	24.50	79	66 (84%)
1738	Roasted coffee	3.09	72	62 (86%)
^aRetrieved from FAPAS Series 17 Rounds 31–38, Reports 1731–1738 (FAPAS 2004–2005); ^bAssigned value, calculated from the most appropriate measure of central tendency of participants’ results; ^cTotal number of scores, number of participants laboratories; ^dNumber of satisfactory scores, number of laboratories returning results with a z-score within the range of ±2.

Nesheim , S , Hardin , NF , Trucksess , MW and Eppley , J . 1973 . Analysis of ochratoxins A and B and their esters in barley, using partition and thin-layer chromatography . II collaborative study. Journal of AOAC International , 56 : 817 – 821 .

 Google Scholar

Levi . 1975 . Collaborative study of a method for the determination of ochratoxin A in green coffee . Journal of AOAC International , 58 : 258 – 262 .

 Google Scholar

Nesheim , S , Stack , ME , Trucksess , RM and Eppley , J . 1992 . Rapid solvent-efficient method for liquid chromatographic determination of ochratoxin A in corn, barley, and kidney: collaborative study . Journal of AOAC International , 75 : 481 – 488 .

 Google Scholar

EN 15141-2 . 1998 . Foodstuffs . Determination of ochratoxin A in cereals and cereal products–Part 1: high performance liquid chromatographic method with bicarbonate clean up ,

 Google Scholar

Larsson , K and Moller , T . 1996 . Liquid chromatographic determination of ochratoxin A in barley, wheat bran, and rye by the AOAC/IUPAC/NMKL method: NMKL collaborative study . Journal of AOAC International , 79 : 1102 – 1105 .

 Web of Science ®Google Scholar

Majerus , P , Weber , R and Wolff , J . 1994 . Detection and determination of ochratoxin A in cereals and cereal products . Journal of Federal Health Office , 37 : 454 – 458 .

 Google Scholar

Entwisle , AC , Williams , AC , Mann , PJ , Slack , PT and Gilbert , J . 2000 . Liquid chromatographic method with immunoaffinity column cleanup for determination of ochratoxin A in barley: collaborative study . Journal of AOAC International , 83 : 1377 – 1383 .

 PubMed Web of Science ®Google Scholar

Entwisle , AC , Williams , AC , Mann , PJ , Russell , J , Slack , PT and Gilbert , J . 2001 . Combined phenyl silane and immunoaffinity column cleanup with liquid chromatography for determination of ochratoxin A in roasted coffee: collaborative study . Journal of AOAC International , 84 : 444 – 450 .

 PubMed Web of Science ®Google Scholar

Visconti , A , Pascale , M and Centonze , G . 2001 . Determination of ochratoxin A in wine and beer by immunoaffinity column and liquid chromatographic analysis with fluorometric detection: collaborative study . Journal of AOAC International , 84 : 1818 – 1827 .

 PubMed Web of Science ®Google Scholar

Brera , C , Grossi , S and Miraglia , M . 2005 . Interlaboratory study for ochratoxin A determination in cocoa powder samples . Journal of Liquid Chromatography and Related Technologies , 28 : 35 – 61 .

 Web of Science ®Google Scholar

MacDonald , S , Anderson , S , Brereton , P and Wood , R . 2003 . Determination of ochratoxin A in currants, raisins, sultanas, mixed dried fruit, and dried figs by immunoaffinity column cleanup with liquid chromatography: interlaboratory study . Journal of AOAC International , 86 : 1164 – 1171 .

 PubMed Web of Science ®Google Scholar

Chan , D , MacDonald , SJ , Bought , V and Brereton , P . 2004 . Simultaneous determination of aflatoxins and ochratoxin A in food using a fully automated immunoaffinity column clean-up and liquid chromatography-fluorescence detection . Journal of Chromatography A , 1059 : 13 – 16 .

 PubMed Web of Science ®Google Scholar

Amezqueta , S , Gonzalez-Penas , E , Murillo , M and Lopez de Cerain , A . 2004 . Validation of a high-performance liquid chromatography analytical method for ochratoxin A quantification in cocoa beans . Food Additives and Contaminants , 2004 : 1096 – 1106 .

 Google Scholar

FAPAS (Food Analysis Performanec Assessment Scheme) . 2004–2005 . Ochratoxin Analysis , FAPAS® Series 17 Sand Hutton, York, , UK : Central Science Laboratory . Rounds 31–38. Reports 1731–1738, May 2004–March 2005

 Google Scholar