SIST EN 14352:2005

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Lebensmittel - Bestimmung von Fumonisin B1 und B2 in Maiserzeugnissen - HPLC-Vefahren mit Immunoaffinitätssäulen-ReinigungProduits alimentaires - Dosage des fumonisines B1 et B2 dans des aliments a base de mais - Méthode CLHP avec purification par colonne d'immunoaffinitéFoodstuffs - Determination of fumonisin B1 and B2 in maize based foods - HPLC method with immunoaffinity column clean up67.060QMLKCereals, pulses and derived productsICS:Ta slovenski standard je istoveten z:EN 14352:2004SIST EN 14352:2005en01-januar-2005SIST EN 14352:2005SLOVENSKI
STANDARD



SIST EN 14352:2005



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14352July 2004ICS 67.060English versionFoodstuffs - Determination of fumonisin B1 and B2 in maizebased foods - HPLC method with immunoaffinity column cleanupProduits alimentaires - Dosage des fumonisines B1 et B2dans des aliments à base de maïs - Méthode CLHP avecpurification par colonne d'immunoaffinitéLebensmittel - Bestimmung von Fumonisin B1 und B2 inMaiserzeugnissen - HPLC-Vefahren mitImmunoaffinitätssäulen-ReinigungThis European Standard was approved by CEN on 30 April 2004.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2004 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14352:2004: ESIST EN 14352:2005



EN 14352:2004 (E) 2 Contents page Foreword.3 1 Scope.4 2 Normative references.4 3 Principle.4 4 Reagents.4 5 Apparatus.7 6 Sampling.8 7 Procedure.8 8 Calculation.10 9 Precision.10 10 Test report.12 Annex A (informative)
Precision data.14 Annex B (informative)
Typical chromatograms.16 Bibliography.18
SIST EN 14352:2005



EN 14352:2004 (E) 3 Foreword This document (EN 14352:2004) has been prepared by Technical Committee CEN/TC 275 “Food analysis - Horizontal methods”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2005, and conflicting national standards shall be withdrawn at the latest by January 2005. WARNING — Fumonisins are hepatotoxic, nephrotoxic and carcinogenic to rats and mice. Effects on humans are not fully known. Observe appropriate safety precautions for handling fumonisins. Any laboratory spills should be washed with 5 % solution of sodium hypchlorite. Acetonitrile is hazardous and samples shall be shaken using a shaker, which is housed within a fume cupboard.
The use of this standard can involve hazardous materials, operations and equipment. This standard does not purport to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. SIST EN 14352:2005



EN 14352:2004 (E) 4
1 Scope This document specifies a method for the detemination of fumonisin B1 (FB1) and fumonisin B2 (FB2) in maize based foods using high performance liquid chromatography (HPLC) and immunoaffinity clean-up, see [1], [2], [3]. The method has been successfully validated in a collaborative study according to AOAC Guidelines for collaborative study procedures [4] to validate characteristics of a method of analysis for the determination of fumonisins in maize flour and corn flakes containing 323 µg/kg to 1414 µg/kg FB1 and 90 µg/kg to 558 µg/kg FB2. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987). 3 Principle Fumonisins are extracted from the sample with a mixture of water, methanol and acetonitrile. The filtered extract is purified by immunoaffinity column and fumonisins are eluted with methanol. The extract is evaporated and the residue is redissolved in a mixture of acetonitrile and water and o-phthaldialdehyde-2-mercaptoethanol (OPA-MCE) is added to form fluorescent fumonisin derivatives. The derivatives are analysed by reverse-phase high performance liquid chromatography (RP-HPLC) with fluorescence detection. 4 Reagents 4.1 General During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of grade 1 according to EN ISO 3696. Solvents shall be of quality for HPLC analysis. 4.2 Methanol 4.3 Acetonitrile 4.4 o-phosphoric acid, volume fraction ϕ(H3PO4) = 85 % 4.5 o-phthaldialdehyde (OPA) 4.6 2-mercaptoethanol (MCE) 4.7 Sodium dihydrogen phosphate solution, substance concentration c(NaH2PO4·2H2O) = 0,1 mol/l
Dissolve 15,6 g of NaH2PO4·2H2O in 1 l of distilled water. SIST EN 14352:2005



EN 14352:2004 (E) 5 4.8 Disodium tetraborate solution, c(Na2B4O7·10H2O) = 0,1 mol/l Dissolve 3,8 g Na2B4O7·10H2O in 100 ml of distilled water. 4.9 Sodium chloride (NaCl) 4.10 Disodium hydrogen phosphate (Na2HPO4) 4.11 Potassium dihydrogen phosphate (KH2PO4) 4.12 Potassium chloride (KCl) 4.13 Hydrochloric acid (HCl), concentrated 4.14 Extraction solvent Mix 25 volume parts of acetonitrile (4.3) with 25 volume parts of methanol (4.2) and 50 volume parts of water. 4.15 Acetonitrile-water solution, volume fraction ϕ(CH3CN) = 50 % Mix 50 volume parts of acetonitrile (4.3) with 50 volume parts of water. 4.16 Phosphate buffered saline (PBS) Dissolve 8,0 g of sodium chloride (4.9), 1,2 g of disodium hydrogen phosphate (4.10), 0,2 g of potassium dihydrogen phosphate (4.11) and 0,2 g of potassium chloride (4.12) in approximately 990 ml of water. Adjust pH to 7,0 with concentrated hydrochloric acid (4.13) and bring to 1 l with water. Phosphate buffered saline tablet or ready-to-use solutions can also be used. 4.17 Immunoaffinity column (IAC) The column shall contain antibodies raised against FB1 and fumonisin FB2. The column shall have a total capacity of not less than 5 µg of fumonisins and shall give a recovery of not less than 90 % for FB1 and FB2 when applied as a standard solution in a mixture of methanol and PBS containing 5 µg of fumonisins. Up to 10 volume parts of methanol or acetonitrile may be used in the mixture with PBS. The columns shall be warmed up to room temperature before use. 4.18 HPLC mobile phase Mix 77 volume parts of methanol (4.2) with 23 volume parts of sodium dihydrogen phosphate solution (4.7). Adjust to pH 3,35 with o-phosphoric acid (4.4). Filter the solution through a membrane filter (5.14). The mobile phase composition may have to be adjusted to conform to individual HPLC column characteristics. 4.19 Derivatization reagent Dissolve 40 mg of OPA (4.5) in 1 ml of methanol (4.2) and dilute with 5 ml of disodium tetraborate solution (4.8). Add 50 µl of MCE (4.6) and mix. The solution is stable for up to one week at room temperature in the dark in a capped amber vial. 4.20 Stock solutions of FB1 and FB2 Prepare a stock solution of FB1 and a stock solution of FB2 in acetonitrile-water (4.15) at a mass concentration of 50 µg/ml for each standard substance. Store the solutions at approximately 4 °C. SIST EN 14352:2005



EN 14352:2004 (E) 6 Fumonisin stock solutions are stable for at least 6 months when stored at approximately 4 °C. 4.21 Mixed fumonisins stock solution Prepare a mixed stock solution by pipetting 1000 µl of the FB1 stock solution and 500 µl of the FB2 stock solution into a 5 ml volumetric flask. Dilute to the mark with the acetonitrile-water solution (4.15) and shake well to obtain a mixed stock solution containing 10 ng FB1/µl and 5 ng FB2/µl. This solution is stable at + 4 °C for at least 6 months. Smaller volumes may be used to prepare the mixed fumonisins stock solution. 4.22 Mixed fumonisins standard solutions for HPLC Prepare four HPLC mixed standard solutions in 5 ml volumetric flasks according to Table 1. Dilute each standard solution to volume (5 ml) with acetonitrile-water solution (4.15) and mix well. This solution is stable at + 4 °C for at least 6 months. Smaller volumes may be used to prepare the mixed fumonisins standard solution. Table 1 — Preparation of mixed standard solutions for HPLC Final fumonisin concentration of mixed standard solution, ng/µl Mixed standard solution Volume taken from mixed stock solution (µl) Addition of acetonitrile-water solution (µl) FB1 FB2 1 50 4 950 0,10 0,050 2 125 4 875 0,25 0,125 3 500 4 500 1,00 0,500 4 1 000 4 000 2,00 1,000 SIST EN 14352:2005



EN 14352:2004 (E) 7 5 Apparatus 5.1 Usual laboratory equipment
and, in particular, the following: 5.2 Orbital shaker 5.3 Centrifuge bottle of 250 ml capacity with screw cap 5.4 Centrifuge capable of a centrifugal force up to 2 500 g 5.5 Filter papers, with a pore size of 20 µm to 25 µm 5.6 Glass microfiber filter papers, with a pore size of 11 µm 5.7 Reservoir, 25 ml with luer tip connector for immunoaffinity column (IAC) 5.8 Microlitre syringe(s) or calibrated micropipette(s), 25 µl to 1 000 µl 5.9 Laboratory balance, capable of weighing to the nearest 0,01 g 5.10 Analytical balance capable of weighing to the nearest 0,1 mg 5.11 Vacuum manifold to accommodate immunoaffinity columns 5.12 Vortex mixer 5.13 Solvent evaporator, with heating module, or similar. 5.14 Membrane filter for aqueous solutions, with a pore size of 0,45 µm. 5.15 HPLC apparatus, comprising the following 5.15.1 HPLC pump, isocratic, suitable for e.g. 1 ml/min constant flow rate 5.15.2 Injection system capable to deliver e.g. 20 µl 5.15.3 Analytical reverse-phase separating column, for example octyldecylsilane (ODS), which ensures a baseline resolution of the fumonisin peaks from all other peaks, with the following characteristics:  stainless steel;  a length of 150 mm;  an inner diameter of 4,6 mm;  a stationary phase with particle size of 5 µm;  a suitable corresponding reverse-phase guard column. SIST EN 14352:2005



EN 14352:2004 (E) 8 Columns of other dimensions may also be used. 5.15.4 Fluorescence detector, fitted with a flow cell and set at 335 nm (excitation) and 440 nm (emission). Detection of at least 0,5 ng of FB1 and FB2 should be possible (signal to noise = 3). 5.15.5 Data system 6 Sampling It is important that the laboratory receives a sample, which is truly representative and has not been damaged during transport or storage. 7 Procedure 7.1 Preparation of the test sample Grind the sample to pass through a 1 mm sieve and homogenize the sample. 7.2 Extraction Weigh, to the nearest 0,1 g, a 20 g test sample into a 250 ml centrifuge bottle (5.3) and add 50 ml of extraction solvent (4.14). Cover centrifuge bottle and shake for 20 min with
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