SIST EN 14627:2005

SLOVENSKI STANDARD
SIST EN 14627:2005
01-september-2005
äLYLOD'RORþHYDQMHHOHPHQWRYYVOHGRYLK'RORþHYDQMHFHORWQHJDDU]HQDLQVHOHQD
]PHWRGRDWRPVNHDEVRUSFLMVNHVSHNWURPHWULMHKLGULGQDWHKQLND+*$$6SR
UD]NORSXSRGWODNRP
Foodstuffs - Determination of trace elements - Determination of total arsenic and
selenium by hydride generation atomic absorption spectrometry (HGAAS) after pressure
digestion
Lebensmittel - Bestimmung von Elementspuren - Bestimmung von Gesamtarsen und
Selen mit Atomabsorptionsspektrometrie-Hydridtechnik (HGAAS) nach Druckaufschluss
Produits alimentaires - Dosage des éléments traces - Dosage de l'arsenic total et du
sélénium par spectrométrie par absorption atomique par génération d'hydrures (SAAGH)
apres digestion sous pression
Ta slovenski standard je istoveten z: EN 14627:2005
ICS:
67.050 Splošne preskusne in General methods of tests and
analizne metode za živilske analysis for food products
proizvode
SIST EN 14627:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 14627:2005

---------------------- Page: 2 ----------------------

SIST EN 14627:2005
EUROPEAN STANDARD
EN 14627
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2005
ICS 67.050
English version
Foodstuffs - Determination of trace elements - Determination of
total arsenic and selenium by hydride generation atomic
absorption spectrometry (HGAAS) after pressure digestion
Produits alimentaires - Dosage des éléments traces - Lebensmittel - Bestimmung von Elementspuren -
Dosage de l'arsenic total et du sélénium par spectrométrie Bestimmung von Gesamtarsen und Selen mit
par absorption atomique par génération d'hydrures Atomabsorptionsspektrometrie-Hydridtechnik (HGAAS)
(SAAGH) après digestion sous pression nach Druckaufschluss
This European Standard was approved by CEN on 15 March 2005.
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 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 translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
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 STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14627:2005: E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN 14627:2005
EN 14627:2005 (E)
Contents
Foreword .3
1 Scope .4
2 Normative references .4
3 Principle.4
4 Reagents.5
5 Apparatus and equipment.8
6 Procedure .8
7 Calculation.10
8 Limit of quantification.10
9 Precision.11
10 Test report .12
Annex A (informative) Results of the inter-laboratory tests.13
Bibliography.15

2

---------------------- Page: 4 ----------------------

SIST EN 14627:2005
EN 14627:2005 (E)
Foreword
This document (EN 14627:2005) 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 October 2005, and conflicting national standards shall be withdrawn at the latest
by October 2005.
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.
3

---------------------- Page: 5 ----------------------

SIST EN 14627:2005
EN 14627:2005 (E)
1 Scope
This European Standard specifies two methods: one method for the determination of total arsenic and another
method for the determination of selenium in foodstuffs by hydride generation atomic absorption spectrometry
(HGAAS) after pressure digestion.
Specific foodstuffs for which European Standards exist are excluded from the scope of this horizontal European
Standard. It is the task of the analyst to review if vertical standards exist.
For the determination of total arsenic in high concentration in e.g. seafood, the method specified in EN 14332 can
be used.
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 13804 Foodstuffs — Determination of trace elements — Performance criteria, general considerations and
sample preparation.
EN 13805 Foodstuffs — Determination of trace elements — Pressure digestion.
3 Principle
3.1 General
Determination of the element to be determined in the test solution by HGAAS after pressure digestion according to
EN 13805.
WARNING — The use of this standard may 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 health and safety practices and determine the
applicability or regulatory limitations prior to use.
3.2 Determination of total arsenic
Arsenic ions are converted to arsenic hydride by sodium borohydride in an acid solution. Arsenic hydride is
transferred by a gas stream into a heated measurement cell and decomposed. Arsenic is determined at 193,7 nm.
Since arsenic (III) and arsenic (V) show a different sensitivity with the hydride technique, it is necessary to reduce
arsenic (V) to arsenic (III) in order to avoid incorrect measurements.
A digestion temperature up to 320 °C may be necessary in order to enable the hydridisation of the arsenic
compounds and in order to determine all different arsenic species in the foodstuff.
NOTE This known fact in the case of materials of marine origin was additionally observed for Rice powder and Kidney
powder during the inter-laboratory tests for this procedure.
3.3 Determination of selenium
Selenium ions are converted to selenium hydride by sodium borohydride in an acid solution. This selenium hydride
is transferred by a gas stream into a heated measurement cell and decomposed. Selenium is determined at
196,0 nm.
4

---------------------- Page: 6 ----------------------

SIST EN 14627:2005
EN 14627:2005 (E)
Selenium (VI) is not determined by the hydridisation as described here. It is therefore necessary to adjust the
digestion conditions to yield only selenium (IV). Digestion temperatures greater than 280 °C can lead to increased
formation of selenium (VI).
4 Reagents
4.1 General
The concentration of the element to be determined in the reagents and water used shall be low enough not to
affect the results of the determination.
Commercially available stock standard solutions should preferably be accompanied by a certificate (see 4.2.8 and
4.3.6).
4.2 Reagents for the determination of arsenic
4.2.1 Hydrochloric acid, 30 %, (mass concentration), ρ(HCl) = 1,15 g/ml.
4.2.2 Nitric acid, at least 65 %, of approximately ρ(HNO ) = 1,4 g/ml.
3
4.2.3 Diluted nitric acid, mix nitric acid (4.2.2) and water in a proportion of 1 + 1 parts by volume.
4.2.4 Sodium borohydride solution, e.g. substance concentration c = 2 g/l (if, for example, the flow injection
procedure is used, see 6.3.1 (3)).
Dissolve 2 g of sodium hydroxide pellets in water, add 2 g of sodium borohydride and dilute to 1000 ml with water.
A fresh solution shall be prepared daily and filtered before use.
The concentration by mass of the sodium borohydride solution may vary with the system and the instructions of the
relevant manufacturer shall therefore be observed.
4.2.5 Diluted hydrochloric acid, e.g. mass fraction w = about 3 % (carrier solution, only for use in the flow
injection procedure).
Dilute approximately 90 ml of hydrochloric acid (4.2.1) to 1000 ml with water.
The concentration by mass of the carrier solution may vary with the system and the instructions of the relevant
manufacturer shall therefore be observed.
4.2.6 Potassium iodide/ascorbic acid solution
Dissolve 3 g of potassium iodide and 5 g of ascorbic acid in water and dilute to 100 ml.
Prepare a fresh solution daily.
The concentrations of the potassium iodide and ascorbic acid may vary slightly with the system and the instructions
of the relevant manufacturer shall therefore be observed.
4.2.7 Hydroxyl ammonium chloride solution
Dissolve 10 g of hydroxyl ammonium chloride in 100 ml of water.
4.2.8 Arsenic stock solution, with an arsenic mass concentration of 1000 mg/l.
If commercial stock solutions are not available, proceed as follows: Dissolve 1,320 g of diarsenic trioxide (As O ) in
2 3
25 ml of potassium hydroxide solution (c= 20 g/100 ml), neutralize with 20 % (mass fraction) sulfuric acid with
5

---------------------- Page: 7 ----------------------

SIST EN 14627:2005
EN 14627:2005 (E)
phenolphthalein as indicator and dilute to 1000 ml with 1 % (mass fraction) sulfuric acid.
4.2.9 Arsenic standard solutions
Dilute the arsenic stock solution (4.2.8) in several steps. The arsenic standard solutions shall contain an adequate
amount of hydrochloric acid, e.g. 2 ml of hydrochloric acid (4.2.1) per 100 ml.
Example of a dilution series:
1000 mg/l → 50 mg/l → 5 mg/l → 0,1 mg/l
5/100 5 / 50 1/ 50
A standard solution of 5 mg/l arsenic in 0,6 % (mass concentration) hydrochloric acid is stable for at least one
week.
4.2.10 Arsenic calibration solutions
Prepare five calibration solutions in the required calibration range from the standard solution of 0,1 mg/l (4.2.9),
ensuring that the concentrations of the calibration solutions are not outside the linear range of the calibration
function and are also in the expected sample content range. The concentration of acid in the calibration solutions
shall be equal to that in the sample solution.
Example for the 1 µg/l to 10 µg/l range:
0,1 mg/l → 1 µg/l
1/100
  → 3 µg/l
3/100
  → 5 µg/l
5/100
  → 8 µg/l
8/100
  → 10 µg/l
10 /100
The calibration solutions may also be prepared from the appropriately diluted standard solution in the measurement
vessel itself by adding the reagents for the pre-reduction (see 6.1.2).
Prepare fresh calibration solutions daily.
The following procedure is recommended for the preparation of standard and calibration solutions. Pour some
water into the volumetric flask and add the requisite amount of acid. After cooling to room temperature, add the
stock or standard solution using a pipette and dilute to the mark with water.
4.2.11 Zero member compensation solution, containing water and acid in a concentration equal to that in the
sample solution.
4.3 Reagents for the determination of selenium
4.3.1 Hydrochloric acid, 25 % (mass concentration), ρ(HCl) = 1,13 g/ml.
4.3.2 Nitric acid, see 4.2.2.
6

---------------------- Page: 8 ----------------------

SIST EN 14627:2005
EN 14627:2005 (E)
4.3.3 Diluted nitric acid, see 4.2.3.
4.3.4 Sodium borohydride solution, see 4.2.4.
The concentration by mass of the sodium borohydride solution may vary with the system. The instructions of the
relevant manufacturer shall therefore be observed.
4.3.5 Diluted hydrochloric acid, e.g. w = about 3 % (carrier solution, only for use in the flow injection
procedure).
Dilute approximately 110 ml of hydrochloric acid (4.3.1) to 1000 ml with water.
The concentration by mass of the carrier solution may vary with the system. The instructions of the relevant
manufacturer shall therefore be observed.
4.3.6 Selenium stock solution, with a selenium concentration of 1000 mg/l.
If commercial stock solutions are not available, proceed as follows: Dissolve 1,405 g of selenium dioxide (SeO )
2
and 2 g of sodium hydroxide in approximately 50 ml water, and dilute to 1000 ml with water.
4.3.7 Selenium standard solution
Dilute the stock solution (4.3.6) in several steps. The solutions shall contain an adequate amount of hydrochloric
acid, e.g. 2 ml of hydrochloric acid (4.3.1) per 100 ml.
Example of a dilution series:
1000 mg/l → 50 mg/l → 5 mg/l → 0,1 mg/l
5/100 5/ 50 1/ 50
A standard solution of 5 mg/l selenium in 0,5 % (mass fraction) hydrochloric acid is stable for at least one week.
4.3.8 Selenium calibration solutions
Prepare five calibration solutions in the required calibration range from the standard solution of 0,1 mg/l (4.3.7),
ensuring that the concentrations of the calibration solutions are not outside the linear range of the calibration
function and are also in the expected sample content range. The concentration of acid in the calibration solutions
shall be equal to that in the sample solution.
Example for the 1 µg/l to 10 µg/l range:
0,1 mg/l → 1 µg/l
1/100
  → 3 µg/l
3/100
  5 µg/l
→
5/100
  → 8 µg/l
8/100
  → 10 µg/l
10 /100
Prepare fresh calibration solutions daily.
The following procedure is recommended for the preparation of standard and calibration solutions. Pour some
water into the volumetric flask and add the requisite amount of acid. After cooling to room temperatu
...