EN 17266:2019

SLOVENSKI STANDARD
01-januar-2020
Živila - Določevanje elementov in njihovih kemijskih oblik - Določevanje organskih
živosrebrovih spojin v morski hrani z analizo elementarnega živega srebra
Foodstuffs - Determination elements and their chemical species - Determination of
organomercury in seafood by elemental mercury analysis
Lebensmittel - Bestimmung von Elementen und ihren Verbindungen - Bestimmung von
Organoquecksilber in Fisch- und Meeresfrüchten mit Feststoffquecksilberbestimmung
Produits alimentaires - Dosage des éléments et de leurs espèces chimiques - Dosage du
mercure organique dans les fruits de mer par analyse du mercure élémentaire
Ta slovenski standard je istoveten z: EN 17266:2019
ICS:
67.120.30 Ribe in ribji proizvodi Fish and fishery products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17266
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2019
EUROPÄISCHE NORM
ICS 67.120.30
English Version
Foodstuffs - Determination elements and their chemical
species - Determination of organomercury in seafood by
elemental mercury analysis
Produits alimentaires - Dosage des éléments et de leurs Lebensmittel - Bestimmung von Elementen und ihren
espèces chimiques - Dosage du mercure organique Verbindungen - Bestimmung von Organoquecksilber in
dans les produits de la mer par analyse du mercure Fisch und Meeresfrüchten mittels Elementaranalyse
élémentaire von Quecksilber
This European Standard was approved by CEN on 9 September 2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17266:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Reagents . 5
6 Apparatus and equipment . 7
7 Procedure. 8
7.1 Sample preparation . 8
7.2 Reagent blank solution . 8
7.3 Determination by elemental mercury analyser . 8
7.4 Instrumental parameters . 9
7.5 Analytical sequence . 9
8 Quality control . 9
8.1 Recovery . 9
8.2 Instrument verification . 10
8.3 Calibration curve . 10
8.4 Absence of contamination . 11
9 Evaluation . 11
9.1 Calculation . 11
9.2 Expression of results . 11
10 Precision . 11
10.1 General . 11
10.2 Repeatability . 11
10.3 Reproducibility . 11
11 Test report . 12
Annex A (informative) Precision data . 13
Bibliography . 15

European foreword
This document (EN 17266:2019) 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 May 2020, and conflicting national standards shall be
withdrawn at the latest by May 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
1 Scope
This document specifies a method for the determination of organomercury in seafood by elemental
mercury analysis. The method has been successfully validated in an interlaboratory study on oyster
tissue, mussel tissue, lobster hepatopancreas, dogfish liver and tuna at levels from 0,01 mg/kg to
5 mg/kg referring to dry weight and expressed as mercury [1], [2].
The limit of quantification is approximately 0,01 mg/kg of organomercury [3], [4].
Organic species of mercury, other than monomethylmercury, are also extracted and thus determined
with this method. However, in seafood the contribution from organic species of mercury other than
monomethylmercury is negligible.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 13804, Foodstuffs - Determination of elements and their chemical species - General considerations and
specific requirements
EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696)
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
4 Principle
Organomercury in seafood/fishery products is separated from the matrix by double liquid-liquid
extraction, first with an organic solvent (toluene) and subsequently with L-cysteine solution and is
determined by elemental mercury analyser [3], [4].
Elemental mercury analyser, also known as automated or direct mercury analyser, is a single purpose
atomic absorption spectrophotometer for mercury determination. The determination of mercury with
an elemental mercury analyser is based on sample drying and subsequent thermal decomposition,
including electro thermal atomisation of mercury. A gold amalgamator selectively traps and pre-
concentrates the mercury from the flow of decomposition products. Finally, the trapped mercury is
thermally released and detected by atomic absorption at 253,7 nm. Organomercury results are
expressed in mg/kg as mercury.
Alternative detection techniques can be used, provided that equivalence of method performance is
proven.
5 Reagents
The mass concentration of mercury in the reagents and water used shall be low enough not to affect the
results. All reagents shall be of analytical grade, i.e. pro analysis, p.a. or similar unless otherwise
specified.
Use water conforming to grade 2 of EN ISO 3696.
5.1 Nitric acid, mass fraction, w (HNO ) = 65 % (m/m), density approximately 1,4 g/ml
5.2 Hydrochloric acid, w (HCl) = 32 % (m/m), density approximately 1,18 g/ml
5.3 Diluted hydrochloric acid solution
Mix equal volumes of hydrochloric acid (5.2) and water.
5.4 Hydrobromic acid, w (HBr) approximately 47 %, density approximately 1,47 g/ml
5.5 Toluene
1)
5.6 L-cysteine monohydrate hydrochloride, e.g. Ph. Eur. or USP grade
5.7 Sodium sulfate anhydrous
5.8 Sodium acetate anhydrous
5.9 L-cysteine solution, mass concentration ρ = 1 g/100 ml
Weigh 1,0 g of L-cysteine monohydrate hydrochloride (5.6), 12,5 g of sodium sulfate (5.7) and 0,8 g of
sodium acetate (5.8) into a 100 ml beaker. Add about 75 ml of water and stir until complete dissolution.
Transfer this solution completely to a 100 ml volumetric flask and make up to volume with water. This
solution can be stored for 1 day at ambient temperature. Other preparation volumes may be used as
long as proportions are kept.
The mass concentration of mercury in the L-cysteine solution should be as low as possible. The purity of
this solution should be such that the response for mercury shall be less than half the response of the
1 µg/l mercury standard solution (calibration solution 1, see 5.13).
L-cysteine precipitates on the catalytic tube which should thus be changed or cleaned as appropriate.
5.10 Mercury stock solution, ρ(Hg) = 1 000 mg/l Hg
5.11 Monomethylmercury (MMHg) chloride, minimum purity of 95 %
5.12 Mercury standard solutions
5.12.1 Mercury standard solution 1 (ρ = 10 mg/l Hg)
Pipette 1,0 ml of the commercial mercury stock solution 1 000 mg/l Hg (5.10) in a 100 ml volumetric
flask, add 2,0 ml of diluted hydrochloric acid solution (5.3) and make up to volume with water. This
solution is stable in a glass container in the refrigerator at approximately 2 °C to 10 °C for 6 months.
5.12.2 Mercury standard solution 2 (ρ = 0,50 mg/l Hg)

1)
Ph. Eur. = European Pharmacopoeia; USP = United States Pharmacopoeia.
Pipette 2,5 ml of mercury standard solution 1 (5.12.1) in a 50 ml volumetric flask, add 1,0 ml of diluted
hydrochloric acid solution (5.3) and make up to volume with water. This solution is stable in a glass
container in the refrigerator at approximately 2 °C to 10 °C for 2 months.
5.13 Calibration solutions
Due to the highly stable response of elemental mercury analysers, there is no need to recalibrate for
each analytical sequence. Calibration is usually stable for at least 1 year. For that reason every
instrumental calibration will be maintained for that period, provided that quality controls for each
sequence are satisfactory. Nevertheless,
...