Animal feeding stuffs - Determination of calcium, sodium, phosphorus, magnesium, potassium, sulphur, iron, zinc, copper, manganese, cobalt and molybdenum after pressure digestion by ICP-AES

This Technical Specification specifies a method for the determination of the minerals calcium, sodium, phosphorus, magnesium, potassium and sulphur and the elements iron, zinc, copper, manganese, cobalt, molybdenum in animal feeding stuffs by inductively coupled plasma atomic emission spectrometry (ICP-AES) after pressure digestion.
The method limit of quantification for each element is dependent on the sample matrix as well as of the instrument. The method is not applicable for determination of low concentrations of elements. A limit of quantification of 1 mg/kg should normally be obtained.

Futtermittel - Bestimmung von Calcium, Natrium, Phosphor, Magnesium, Kalium, Schwefel, Eisen, Zink, Kupfer, Mangan, Kobalt und Molybdän nach Druckaufschluss mittels ICP-AES

Aliments pour animaux - Détermination du calcium, du sodium, du phosphore, du magnésium, du potassium, du soufre, du fer, du zinc, du cuivre, du manganèse, du cobalt et du molybdène après digestion sous pression par spectrométrie d'émission atomique à plasma à couplage inductif (spectrométrie ICP-AES)

La présente Spécification Technique spécifie une méthode de détermination de la teneur en minéraux (calcium, sodium, phosphore, magnésium, potassium, souffre) et de la teneur en éléments (fer, zinc, cuivre, manganèse, cobalt, molybdène) présents dans les aliments pour animaux par spectrométrie d'émission atomique à plasma à couplage inductif (spectrométrie ICP AES) après digestion sous pression.
La limite de quantification de la méthode pour chacun des éléments est fonction de la matrice de l'échantillon et de l'instrument. Cette méthode ne permet pas la détermination des éléments en faibles concentrations. Il convient de parvenir à une limite de quantification de 1 mg/kg, dans des conditions normales d'essai.

Krma - Določevanje kalcija, natrija, fosforja, magnezija, kalija, žvepla, železa, cinka, bakra, mangana, kobalta in molibdena po razklopu pod tlakom z ICP-AES

General Information

Status
Withdrawn
Publication Date
31-Jul-2007
Withdrawal Date
07-Feb-2012
Current Stage
9960 - Withdrawal effective - Withdrawal
Start Date
08-Feb-2012
Completion Date
08-Feb-2012

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SLOVENSKI STANDARD
SIST-TS CEN/TS 15621:2007
01-november-2007
.UPD'RORþHYDQMHNDOFLMDQDWULMDIRVIRUMDPDJQH]LMDNDOLMDåYHSODåHOH]DFLQND
EDNUDPDQJDQDNREDOWDDQGPROLEGHQDSRUD]NORSXSRGWODNRP],&3$(6
Animal feeding stuffs - Determination of calcium, sodium, phosphorus, magnesium,
potassium, sulphur, iron, zinc, copper, manganese, cobalt and molybdenum after
pressure digestion by ICP-AES
Futtermittel - Bestimmung von Calcium, Natrium, Phosphor, Magnesium, Kalium,
Schwefel, Eisen, Zink, Kupfer, Mangan, Kobalt und Molybdän nach Druckaufschluss
mittels ICP-AES
Aliments pour animaux - Détermination du calcium, du sodium, du phosphore, du
magnésium, du potassium, du soufre, du fer, du zinc, du cuivre, du manganese, du
cobalt et du molybdene apres digestion sous pression par spectrométrie d'émission
atomique a plasma couplage inductif (spectrométrie ICP-AES)
Ta slovenski standard je istoveten z: CEN/TS 15621:2007
ICS:
65.120 Krmila Animal feeding stuffs
SIST-TS CEN/TS 15621:2007 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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

TECHNICAL SPECIFICATION
CEN/TS 15621
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
August 2007
ICS 65.120

English Version
Animal feeding stuffs - Determination of calcium, sodium,
phosphorus, magnesium, potassium, sulphur, iron, zinc, copper,
manganese, cobalt and molybdenum after pressure digestion by
ICP-AES
Aliments pour animaux - Détermination du calcium, du Futtermittel - Bestimmung von Calcium, Natrium,
sodium, du phosphore, du magnésium, du potassium, du Phosphor, Magnesium, Kalium, Schwefel, Eisen, Zink,
soufre, du fer, du zinc, du cuivre, du manganèse, du cobalt Kupfer, Mangan, Kobalt und Molybdän nach
et du molybdène après digestion sous pression par Druckaufschluss mittels ICP-AES
spectrométrie d'émission atomique à plasma couplage
inductif (spectrométrie ICP-AES)
This Technical Specification (CEN/TS) was approved by CEN on 9 June 2007 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, 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
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15621:2007: E
worldwide for CEN national Members.

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CEN/TS 15621:2007 (E)
Contents Page
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Principle.5
5 Reagents.5
6 Apparatus .6
7 Sampling.6
8 Preparation of the test sample .7
9 Procedure .7
10 Calculation and expression of the result .9
11 Precision.12
12 Test report .15
Annex A (informative) Results of the interlaboratory tests.16
Annex B (informative) Notes on the detection technique, interferences and quantification,
pressure digestion.20

2

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

CEN/TS 15621:2007 (E)
Foreword
This document (CEN/TS 15621:2007) has been prepared by Technical Committee CEN/TC 327 “Animal
feeding stuffs - Methods of sampling and analysis”, the secretariat of which is held by NEN.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and United Kingdom.
3

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CEN/TS 15621:2007 (E)
1 Scope
This Technical Specification specifies a method for the determination of the minerals calcium, sodium,
phosphorus, magnesium, potassium and sulphur and the elements iron, zinc, copper, manganese, cobalt,
molybdenum in animal feeding stuffs by inductively coupled plasma atomic emission spectrometry (ICP-AES)
after pressure digestion.
The method limit of quantification for each element is dependent on the sample matrix as well as of the
instrument. The method is not applicable for determination of low concentrations of elements. A limit of
quantification of 1 mg/kg should normally be obtained.
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 13805: 2002, Foodstuffs – Determination of trace elements – Pressure digestion.
EN ISO 3696:1995, Water for analytical laboratory use – Specification and test methods (ISO 3696:1987).
ISO 6498:1998, Animal feeding stuffs – Preparation of test samples.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
limit of detection (LOD)
smallest measured content, from which it is possible to deduce the presence of the analyte with reasonable
statistical certainty
NOTE The limit of detection is numerically equal to three times the standard deviation of the mean of blank
determinations (n ≥ 10, were n = number of measures) performed under reproducibility conditions.
3.2
limit of quantification (LOQ)
lowest content of the analyte which can be measured with reasonable statistical certainty
NOTE If both trueness and precision are constant over a concentration range around the limit of detection, then the
limit of quantification is numerically equal to ten times the standard deviation of the mean of blank determinations (n ≥ 10,
were n = number of measures) performed under reproducibility conditions.
3.3
feed additives
substances are feed additives when they comply with the definition of feed additives given in regulation EU
1831/2003
3.4
animal feeding stuffs
substances are animal feeding stuffs when they comply with the definition of animal feeding stuffs given in
regulation EU 178/2002
4

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CEN/TS 15621:2007 (E)
4 Principle
For the determination of calcium, sodium, phosphorus, magnesium, potassium, sulphur, iron, zinc, copper,
manganese, cobalt and molybdenum, a test portion of the sample is digested under pressure.
The concentration of the elements is determined by inductively coupled plasma atomic emission spectrometry
(ICP-AES) using external calibration or standard addition technique.
WARNING – The use of this Technical Specification can involve hazardous materials, operations and equipment.
This Specification does not purport to address all the safety problems associated with its use. It is the
responsibility of the user of this Technical Specification to establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to use.
5 Reagents
Use only reagents of recognized analytical grade, unless otherwise specified.
5.1 Water, complying with grade 2 as defined in EN ISO 3696.
5.2 Nitric acid, concentrated, not less than 65 % (mass fraction), c(HNO ) = 14,4 mol/l, having a
3
density of approximately ρ (HNO ) 1,42 g/ml.
3
5.3 Nitric acid solution of 2 % (v/v), to be prepared: pipette 20 ml nitric acid (5.2) in a 1000 ml
volumetric flask (6.4) and fill to the mark with water.
5.4 Hydrogen peroxide, not less than 30 % (mass fraction).
5.5 Element stock solutions
Ca, Na, P, Mg, K, S, Fe, Zn, Cu, Mn, Co, Mo
c = 1000 mg/l.
The user shall choose a suitable stock solution. Both single-element stock solutions and multi-element stock
solutions with adequate specification stating the acid used and the preparation technique are commercially
available. It is advisable to use certified stock solutions.
NOTE Element stock solutions with concentrations different from 1000 mg/l may be used as well.
5.6 Standard solutions
Depending on the scope, different multi-element standard solutions may be necessary. In general, when
combining multi-element standard solutions, their chemical compatibility and the possible hydrolysis of the
components shall be regarded. Spectral interferences from other elements present in multi-element standards
also need to be considered.
Various combinations of elements at different concentrations can be used, provided that the element stock
solutions (5.5) are diluted, with the same acid and equal concentration as the acid in the test solution, to a
range of standards that covers the concentrations of the elements to be determined.
The multi-element standard solutions are considered to be stable for several months, if stored in the dark.
5

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CEN/TS 15621:2007 (E)
6 Apparatus
Usual laboratory apparatus and, in particular, the following.
NOTE For the determination of sodium in low concentrations it is advisable not to use glassware since glassware can
be a source of sodium contamination.
6.1 Laboratory grinder
6.1.1 Laboratory grinder capable of grinding to a particle size of less than or equal to 1 mm, e.g. a knife mill
or equivalent.
6.1.2 Laboratory grinder capable of grinding to a particle size of less than or equal to 0,1 mm, e.g. a ball mill
or equivalent.
6.1.3 Mortar with pestle, free of contamination.
NOTE It should be checked that the mill used does not influence the concentration of elements in the sample (e.g.
adsorption, contamination) which have to be analysed.
6.2 Analytical balance, capable of weighing to an accuracy of 1 mg.
6.3 Pressure digestion apparatus, commercially available.
The apparatus shall be tested for safety pressure vessels made of acid-resistant materials and having holders
for the sample of acid-resistant material with low level of contamination by elements to be determined.
Apparatus is available which uses a high-pressure incinerator with or without ambient autoclave pressure.
Instead of polytetrafluoroethylene (PTFE) holders, it is better to use graduated quartz holders, perfluoro
ethylene propylene (FEP) holders or perfluoro alkoxy (PFA) holders. Quartz is advisable to be used for
decomposition temperatures above 230 °C.
6.4 One-mark volumetric flasks, of capacity 1000 ml.
6.5 Inductively coupled plasma – Atomic Emission Spectrometer
The instrument shall be equipped with radial plasma as a minimum requirement; axial plasma is equally
acceptable. Background correction shall also be performed when necessary. Settings of the working
conditions (e.g. viewing height, gas flows, RF or plasma power, sample uptake rate, integration time, number
of replicates, …) shall be optimised according the manufacturer’s instructions.
6.6 Freeze drying equipment, capable of freeze-drying liquid animal feeding stuffs.
7 Sampling
Sampling is not part of the method specified in this International Standard. A recommended sampling method
is given in EN-ISO 6497[1].
It is important that the laboratory receives a sample which is truly representative and has not been damaged
or changed during transport or storage.
6

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CEN/TS 15621:2007 (E)
8 Preparation of the test sample
8.1 General
Prepare the test sample in accordance with ISO 6498.
 The grinding must be done in conditions such that the substance is not appreciably heated and that no
contamination takes place by the grinding tools.
 The operation is to be repeated as many times as is necessary and it must be affected as quickly as
possible in order to prevent any gain or loss of constituents (water).
 The whole ground product is placed in a flask made of e.g. polypropylene, which can be stoppered and
stored in such way to prevent any change in composition.
 Before any weighing is carried out for the analysis, the whole test sample must be thoroughly mixed for
reasons of homogeneity. Since a maximum of 0,5 g of sample is used for the digestion it is of the utmost
importance to have a homogeneous sample in order to take a representative sub sample.
8.2 Animal feeding stuffs which can be ground as such
Grind the laboratory sample (usually 500 g), using a grinder (6.1.1) or mortar, until a particle size of 1 mm or
less has been reached.
8.3 Liquid animal feeding stuffs
Liquid feeding stuffs shall be pre-dried according to the procedure described in 8.3.1 or freeze-dried according
to the procedure described in 8.3.2.
8.3.1 Pre-drying
Pre-dry the laboratory sample at a temperature of 70 °C ± 5 °C during at least 16 h to reduce the moisture
content. The mass of the sample before and after the pre-drying is to be determined using an analytical
balance (6.2). Grind the pre-dried sample in accordance with 8.2.
8.3.2 Freeze-drying
Freeze-dry the laboratory sample following the instructions of the freeze-drying equipment (6.6). The mass of
the sample before and after the freeze-drying is to be determined using an analytical balance (6.2). Grind the
freeze-dried sample in accordance with 8.2.
8.4 Mineral animal feeding stuffs
Mineral compounds, except mineral products containing crystalline water, e.g. MgCl·6H O, shall be ground
2 2
using a grinder (6.1.2) or mortar until a particle size of 0,1 mm or less has been reached. Mineral products
containing crystalline water should not be ground.
9 Procedure
9.1 Digestion
Use pressure digestion. Proceed in accordance with 9.1.1.
7

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CEN/TS 15621:2007 (E)
9.1.1 Pressure digestion
Match the initial sample mass to the capacity of the digestion vessel, with the manufacturer's instructions
being strictly observed for safety reasons. Determine the necessary digestion temperature and digestion time
in accordance with EN 13805 (see Annex B).
9.1.1.1 Example of microwave digestion
When using 100 ml vessels, weigh about 0,5 g of the prepared test sample to the nearest 1 mg. Add 3 ml of
nitric acid (5.2) and 0,5 ml of hydrogen peroxide (5.4), seal the digestion vessel and the pressure holders in
the correct manner. Leave to pre-digest outside the microwave for about 30 min. Apply low microwave energy
at the beginning of the digestion and slowly raise the energy to the maximum power, e.g. start with 100 W,
raise up to 600 W within 5 min, hold for 5 min, raise to 1000 W, hold for 10 min, cool down for minimum 20
min to 25 min. Treat a blank in the same way.
Dilute the digestion solution accordingly with water. The solution obtained after dilution is called the test
solution. Proceed in accordance with 9.2.
9.1.1.2 Example of a high pressure digestion
When using a 100 ml vessel, weigh about 0,5 g of the prepared test sample to the nearest 1 mg. Add 3 ml of
nitric acid (5.2), seal the digestion vessel and the pressure vessel in the correct manner and heat from room
temperature to 150 °C in 60 min, then to 300 °C in 40 min and keep 300 °C for 90 min before cooling down.
Treat a blank in the same way.
Dilute the digestion solution accordingly with water. The solution obtained after dilution is called the test
solution. Proceed in accordance with 9.2.
9.2 Calibration
Calibration shall be performed by means of external calibration or standard addition technique. It is important
that the measurements are made in the linear range of the instrument. Appropriate matrix matching of the
calibration solutions shall be performed if an (external) calibration method is used (see Annex B).
9.2.1 External calibration
The calibration is performed with at least two calibration solutions of which one blank calibration solution. If the
working range is not linear, the calibration should be performed with a blank calibration solution and at least 3
equidistant calibration solutions.
9.2.2 Standard addition technique
The standard addition curve should consist of at least two points of which one addition. For those elements
whose concentration is near the limit of quantification, the standard addition curve should consist of at least
four points of which three additions. If three additions are used, the concentration of the highest standard
should be 3 to 5 times the concentration in the sample solution.
9.3 Determination
9.3.1 General
Analytical lines, selectivity, limits of detection and quantification, precision, linear working area, and
interferences have to be established before operating the ICP-AES system.
8

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CEN/TS 15621:2007 (E)
9.3.2 Determination by inductively coupled plasma – atomic emission spectrometry
Table 1 — Selected emission wavelengths and interferences for determination with ICP-AES
Element Wavelength of emission (nm) Interference Element Wavelength of emission (nm) Interference
315,887 Co 257,610 Fe, Mo, Cr
Mn
Ca 317,933 Fe, V 293,306 Al, Fe
393,366 202,030 Al, Fe
Mo
Ti
Co 228,616 204,598
324,754 Ti, Fe 330,237
Cu
Na
327,396 588,995
238,200 Co 589,592 Ar
Fe
259,940 178,287 I
P
766,490 Mg, Ar 213,618 Cu, Fe, Mo, Zn
K
769,900 214,914 Cu, Al, Mg
279,079 177,428 Cu

Mg 279,553 181,972
S
285,213 Fe 182,036

 206,200
Zn

P
 213,856

Table 1 gives relevant analytical lines and possible interferences for the determination with ICP-AES. Other
wavelengths than those specified in Table 1 can be used (see also Annex B).
9.3.2.1 External calibration method
Aspirate the blank test solution (9.1), the calibration solutions (9.2.1), and the test solution (9.1) in ascending
order separately into the plasma and measure the emission of the element to be determined.
NOTE If the test solution contains residues, transfer the solution into the test tube from which the test solution is
aspirated into the ICP. Use the first transferred portion to rinse the test tube.
Perform at least two replicates. Average the values if the values fall within an accepted range. After each
measurement, aspirate water or 2 % nitric acid solution (5.3).
9.3.2.2 Standard addition technique
Aspirate the blank test solution (9.1), the test solution (9.1), and the standard addition technique (9.2.2) in
ascending order separately into the plasma, and measure the emission of the element to be determined.
NOTE If the test solution contains residues, transfer the solution into the test tube from which the test solution is
aspirated into the ICP. Use the first transferred portion to rinse the test tube.
Perform at least two replicates. Average the values if the values fall within an accepted range. After each
measurement, aspirate water or 2 % nitric acid solution (5.3).
10 Calculation and expression of the result
NOTE Net signal is defined as the number of counts per second at the selected wavelength, corrected for
background contributions.
9

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CEN/TS 15621:2007 (E)
10.1 External calibration
In the case of a linear calibration curve constructed with one blank calibration solution and one calibration
solution, the calibration function can be described as follows:
S = c × b+ a (1)
st st
where
S is the net signal of the calibration solution;
st
c is the concentration of the calibration solution, in mg/l;
st
b  is the slope;
a is the intersection.

Calculate the element concentration c , in mg/l, in the test solution (9.1) using the slope b and the intersection
f
a found in (1) as follows:
S − a
f
c = (2)
f
b
where
S is the net signal of the test solution.
f
10.2 Standard addition method with only one addition
In the simplest case of standard addition, where only one addition is made, the element concentration c, in
f
mg/l, in the test solution (9.1) is determined as follows:
S ×V × c
0 s s
c = (3)
f
()S − S ×V
1 0 f
where
c is the concentration, in mg/l, of the standard solution;
s
V is the volume, in l, of the standard solution added;
s
V is the volume, in l, of the test solution (9.1) used to prepare the solution without addition;
f
S is the net signal of the solution without addition;
0
S is the net signal after addition.
1
10.3 Standard addition method with several additions
In case of several additions, regression techniques on the linear model of variable y as a function of variable x,
have to be used to determine the element concentration of the test solution (9.1). Generally this model can be
written as:
10

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CEN/TS 15621:2007 (E)
y = a+ b× x (4)
i i
In this particular case of three standard additions,
y = S  (for i = 0, 1, 2, 3) (5)
i i
x = c ×V  (for i = 0, 1, 2, 3) (6)
i s i
where
c is the concentration, in mg/l, of the standard solution;
s
V
 are the various volumes, in l, of the standard solution added;
i
S are the net signals after the various additions.
i
The values of a and b can then be calculated as follows:
n×∑ x y −∑∑x y
i i i i
b = (7)
2
2
n× x −()x
∑∑
i i
∑∑y − b× x
i i
a =  (8)
n
where
n is the number of solutions measured ( n = 4 in case of three additions).
The element concentration c , in mg/l, of the test solution (9.1) can then be found using the following equation:
f
a
b
c = (9)
f
V
f
where
V is the volume, in l, of the test solution (9.1) used to prepare the solution without addition.
f
10.4 Calculation of the element content in the sample
The element content in the sample or mass fraction of element w , expressed in mg of element per kg of
elem
animal feeding stuff, is determined using the following equation:
()c − c
f bl
w = ×V (10)
elem t
m
where
c is the concentration, in mg/l, of the test solution (9.1), as determined using equation (2) or (3) or (9);
f
c is the concentration, in mg/l, of the blank solution;
bl
m is the mass of sample, in kg, taken for the extraction by digestion, and corrected for water content;
V is the total volume, in l, of the test solution (9.1).
t
If the test solution (9.1) has been diluted further, take into account the dilution factor.
11

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CEN/TS 15621:2007 (E)
If the sample has been pre-dried or freeze-dried (8.3), recalculate the result to the fresh weight of the sample
taking into account the loss of moisture during pre-drying or freeze-drying.
The result of the determination is expressed in percentage for the minerals Ca, Na, P, Mg, K and S and in
mg/kg for the other elements Fe, Zn, Cu, Mn, Co, Mo.
11 Precision
11.1 Interlaboratory test
An interlaboratory test has been carried out in 2004. Details of interlaboratory test on precision of the method
are summarized in Annex A. The values derived from these test may not be applicable to concentration
ranges and matrices others than those given.
11.2 Repeatability
The absolute difference between two independent single test results, obtained using the same method on
identical test material in the same laboratory by the same operator using the same equipment within a short
interval of time, will in not more than 5 % of the cases be greater than the repeatability limit r given in Table 2
(minerals Ca, Na, Mg, P, K, S) and Table 3 (elements Fe, Mn, Cu, Zn, Co, Mo).
11.3 Reproducibility
The absolute difference between two single test results, obtained using the same method on identical test
material in the same laboratory with different operators using different equipment, will in not more than 5 % of
the cases be greater than the reproducibility limit R given in Table 2 (minerals Ca, Na, Mg, P, K, S) and Table
3 (elements Fe, Mn, Cu, Zn, Co, Mo).
12

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CEN/TS 15621:2007 (E)
Table 2 — Precision data – Ca, Na, Mg, P, K, S
Ca
_
Samples r (%) R (%)
Mean, x (%)
Pig feed 1,11 0,06 0,30
Sheep feed 0,97 0,09 0,22
Phosphate 10,35 0,81 2,15
Mineral premixture 22,39 1,22 2,84
Mineral mixture 2,30 0,23 0,60
Na
_
Samples r (%) R (%)
Mean, x (%)
Pig feed 0,17 0,03 0,04
Sheep feed 0,41 0,06 0,09
Phosphate 0,11 0,01 0,02
Mineral premixture 6,84 0,87 1,64
Mg
_
Samples r (%) R (%)
Mean, x (%)
Pig feed 0,21 0,02 0,05
Sheep feed 0,37 0,02 0,05
Mineral premixture 0,36 0,02 0,07
P
_
Samples r (%) R (%)
Mean, x (%)
Pig feed 0,48 0,04 0,15
Sheep feed 0,49 0,03 0,12
Phosphate 19,13 0,94 3,19
Mineral premixture 0,10 0,02 0,03
Mineral mixture 0,024 0,004 0,017
K
_
Samples r (%) R (%)
Mean, x (%)
Pig feed 1,01 0,05 0,18
Sheep feed 1,27 0,07 0,21
Phosphate 0,083 0,01 0,03
S
_
r (%) R (%)
Samples
Mean, x (%)
Pig feed 0,28 0,03 0,08
Sheep feed 0,24 0,03 0,03
Phosphate 0,45 0,07 0,15

13

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CEN/TS 15621:2007 (E)
Table 3 — Precision data – Fe, Mn, Cu, Zn, Co, Mo
Fe
_
Samples r (mg/kg) R (mg/kg)
Mean, x
(/ )
Pig feed 325 48 103
Sheep feed 427 41 122
Phosphate 2498 134 565
Mineral premixture 5683 488 1384
Mineral mixture 8550 535 3920
Mn
_
Samples r (mg/kg) R (mg/kg)
Mean, x
(/ )
Pig feed 134 38 44
Sheep feed 98,7 24 32
Phosphate 122 8,5 39
Mineral premixture 3440 489 963
Mineral mixture 213 61 91
Cu
_
Samples r (mg/kg) R (mg/kg)
Mean, x
(/ )
Pig feed 176 34 59
Sheep feed 14,8 1,2 2,6
Phosphate 11,4 1,1 2,7
Mineral premixture 470 47 50
Mineral mixture 7,3 0,5 1,1
Zn
_
Samples r (mg/kg) R (mg/kg)
Mean, x
(/k)
Pig feed 166 18 40
Sheep feed 123 19 45
Phosphate 153 11 62
Mineral premixture 3618 154 273
Mineral mixture 26,6 3,3 16
Co
_
Samples r (mg/kg) R (mg/kg)
Mean, x
(/k)
Pig feed 0,67 0,07 0,30
Sheep feed 1,19 0,18 0,63
Mineral premixture 30,7 2,1 9,1
Mo
_
Samples r (mg/kg) R (mg/kg)
Mean, x
(/ )
Pig feed 1,03 0,15 0,23
Mineral premixture 1,13 0,34 1,09

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CEN/TS 15621:2007 (E)
12 Test report
The test report shall contain at least the following information:
a) the test method used, with reference to this Technical Specification;
b) information necessary for the complete identification of the sample;
c) particular points observed in the course of the test;
d) operation details not specified in this document, or regarded as optional, together with details of any
incidents which might have affected the results;
e) the results obtained of the determination, expressed as mass fraction w , in mg/kg of animal feeding
elem
stuff or in percentage for the minerals.
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CEN/TS 15621:2007 (E)
Annex A
(informative)

Results of the interlaboratory tests
An interlaboratory test has been carried out in 2004 with eight participating laboratories and five different
animal feeding stuffs, including a complete feed for pigs, a complete feed for sheep, a rock phosphate, a
mineral mixture and a mineral premixture. The samples were homogenized centrally and distributed to the
participants. The tests yielded the data given in the tables A.1 and A.2. Repeatability and reproducibility were
calculated according to ISO 5725-1[3].
Table A.1 — Statistical results of interlaboratory tests – Ca, N
...

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