International Measurement Evaluation Programme: IMEP9, trace elements in water

IRMM GE/R/SIM/11/1998Isotope Measurements Unit December1998

The International Measurement Evaluation Programme

IMEP-10 : Trace elements in polyethylene

GRAPHICAL PRESENTATION OF RESULTS

REPORT TO PARTICIPANTS

L. Van Nevel, E. Poulsen, I. Papadakis and P. Taylor

Institute for Reference Materials and Measurements (IRMM)

European Commission – JRC

Retieseweg, B-2440 GEEL (Belgium)

IRMM GE/R/SIM/11/1998Isotope Measurements Unit December1998

The International Measurement EvaluationProgramme

IMEP-10 : Trace elements in polyethylene

GRAPHICAL PRESENTATION OF RESULTS

REPORT TO PARTICIPANTS

L. Van Nevel, E. Poulsen, I. Papadakis and P. Taylor

Institute for Reference Materials and Measurements (IRMM)

European Commission – JRC

Retieseweg, B-2440 GEEL (Belgium)

1. Introduction

The International Measurement Evaluation Programme (IMEP) is the tool with which field

laboratories can compare their results against SI traceable values. Unknown samples are sent to

interested laboratories. These laboratories are asked to return a value together with a statement of

uncertainty claiming to contain the "true value". The SI traceable values, expressed as reference

ranges, are established by measurement procedures based on isotope dilution mass spectrometry

(IDMS) applied as a primary method of measurement (CCQM definition [1]). The underlying

philosophy is that the best values, which will serve as reference ranges, are obtained from well

understood measurement processes rather than via a mere consensus approach. Further

characteristics of the IMEP programme are: participating laboratories work under normal conditions

with their choice of techniques, procedures and instrumentation and are requested to report their

results with a realistic combined uncertainty. IMEP is open to all laboratories with full confidentiality

with respect to the results. IMEP is focused on toxic and essential elements in "real life" samples.

IMEP graphically displays reference values and results from participating laboratories but

conclusions are to be drawn by the laboratories themselves. Support can be offered after the

measurement round.

IMEP is co-ordinated from IRMM. The establishment of reference values (a time-consuming and

expensive exercise) is done in collaboration with several laboratories worldwide, which can

demontrate a record of successful applications of IDMS as a primary method of measurement.

IMEP is complementary to collaborative studies and proficiency testing schemes, the latter having a

weaker metrological basis but higher frequency.

This report presents all participants’ results (in graphical form) obtained in IMEP-round 10 : trace

elements in polyethylene. Participants could measure the content of As, Br, Cd, Cl, Cr, Hg, Pb and

S.

This round was organized because of the general interest in the polymer producing and processing

industry. Moreover, there was a specific need in view of the EC-directive 94/62/EC on packaging

and packaging waste which regulates the amounts of heavy metals, more specifically Cd, Cr, Hg and

Pb in packaging material.

2. IMEP-10 : “Trace elements in polyethylene”

2.1 Material

The material used in this round was a polyethylene material, type HDPE Lupolen K 1800 S (BASF

AG) which was doped by BASF following the instructions of IRMM/DSM with several elements

e.g. As (oxide), Cd (oxide), Cr(IV-oxide), Hg(I-sulphate) and Pb(chromate), halogens (Br,Cl-

phtalocyanine green) and S (sulphate). No UV and thermal stabilizers were added but it contained

significant amounts of Ti (as optical withener). The additives were first mixed with the PE into a

‘master batch’ (a highly concentrated batch) and this batch was diluted with PE. The material was

extruded and cut to a granulate. It consisted of small mm-large grains, each with a weight of about

10 mg. It was mixed at IRMM using tubula-mixing and was stored in a large plastic container at –

20ºC until it was packed in sealed glass amber bottles containing 50 g sample.

The homogeneity was studied using ICP-MS. From these ICP-MS results, at a 100 mg level the

relative uncertainty due to homogeneity was found to be : for Cd 4.9 % and for Pb 1.4% [2].

2.2. Participation in IMEP-10.

Each IMEP-10 participant received one bottle of sample together with a questionnaire (addendum

1) and a report form (addendum 2).

Results were returned by 34 participants from 15 countries. A distribution of the participants as a

function of the country is given in Table 1. Close collaboration with the Swiss regional co-ordinator

resulted in the participation of 10 Swiss laboratories.

Table 1 Country of origin of the reporting IMEP-10 participants

COUNTRY NUMBER OFPARTICIPANTS

AUSTRIA 3BELGIUM 2CYPRUS 1FINLAND 2GERMANY 3ISRAEL 1ITALY 1LUXEMBOURG 1POLAND 1SLOVAK REPUBLIC 1SLOVAKIA 2SWEDEN 2SWITZERLAND 10THE NETHERLANDS 3UNITED KINGDOM 1

TOTAL 34

2.3. Establishment of the certified and the assigned values

In IMEP, the aim is to establish SI-traceable reference values. As mentioned in the introduction, this

is done using a primary method of measurement. In such cases, and when the work is supported by

a thorough estimate of the combined uncertainty, the values are denoted as “certified”. When the

reference value has been established with another method or combination of methods, the term

“assigned value” is used.

Short description of the methods used

Isotope Dilution Mass Spectrometry (IDMS)IDMS has the potential to be a primary method of measurement if well applied. The technique is

based on the measurement of isotope amount ratios for the element concerned. A known amount of

sample with known isotopic composition for the element is mixed with a material (spike) where the

element of interest is present in a different isotopic composition. Once isotopic homogeneity has

been established for the mix (blend), minor losses in the subsequent sample preparation do not affect

the result. For a spike with known amount content and known isotopic composition, the amount

content (cx) of the element in the sample is determined from a measurement of the blend ratio, RB

and calculated from the IDMS equation (below) where m denotes mass (kg), c is the amount

content of the element (mol·kg-1), RB is the isotope amount ratio n(iM)/n(jM) where n denotes

chemical amount (in mol). Index x refers to the sample and index y to the spike.

As can be seen, this equation does not contain factors for instrument sensitivity, which makes it very

robust. Mass discrimination effects can be corrected for by measurements on reference materials

with known isotopic composition, preferably close to that of RB.

The isotope amount ratios are measured with a mass spectrometer. The most commonly applied

techniques to generate ions in inorganic mass spectrometry are thermal ionisation mass spectrometry

(TIMS) and inductively coupled plasma mass spectrometry (ICP-MS). In TIMS, the sample is

loaded onto a metal filament. Heating the filament in the ion source induces ion formation from the

solid or molten sample. In ICP-MS, the sample is normally introduced as a solution. After removal

of solvent, ions are formed from the atomised salt particles in a plasma, typically at temperatures

around 8000 K.

Neutron Activation Analysis (NAA)NAA is an analytical method based on gamma spectrometric measurements of samples irradiated

with neutrons in a nuclear reactor. The capture of a neutron in a stable isotope may lead to the

immediate emission of a γ-ray and the formation of a γ−emitter isotope and the corresponding

γ−emission is measured.

Classical NAA is based on comparison of activities of the unknown sample and a known standard

co-irradiated under similar conditions. This approach eliminates the need for accurate determination

of neutron fluxes and detector calibration. The required measurements are the relative specific γ-

emission of the activity products in the sample and in the standard, measured in the same counting

position. The major drawback is the need of one standard per element concentration to be

determined.

iy

ix

x

yy

xB

Byx R

Rm

mc

RR

RRc

∑∑

⋅⋅

⋅−

−=

The k0-standardisation NAA method was developed in the 1970:s and allows the determination of

elemental concentrations in the sample without the use of mono- or multi-element calibrants.[3] The

method is more flexible but subtle to implement and requires accurate knowledge of,

• the neutron flux parameters - the thermal to epithermal flux ratio and the deviation from

the ideal epithermal neutron flux distribution,

• the characteristics of the gamma spectrometry detector (cf. detection efficiency, peak-to-

total ratio, gamma coincidence corrections, detailed information of the geometry and

composition of the detector),

• tabulated fundamental physical constants, known as k0-factors, proportional to molar

mass, natural abundance, gamma ray intensities and cross sections.

Depending on the half-live of the isotope of interest, different irradiation-cooling (or decay) and

measurement schemes can be used.

Certified and assigned values

In IMEP-10, 8 elements (As, Br, Cd, Cl, Cr, Hg, Pb and S) were under investigation.

Certified values were established for lead, cadmium, chromium and mercury by IDMS while k0-

NAA was used to obtain assigned values for arsenic, chlorine and bromine. To establish the

assigned value for sulfur, data obtained by various methods were combined (k0-NAA, IC and ICP)

[4]. The certified and assigned values are summarized in table 2. The stated uncertainties are

expanded uncertainties, U, with a coverage factor, k, equal to 2. The uncertainties were evaluated

according to recently published international documents.[5,6].

Table 2. Certified and assigned values, amount content, for the elements in IMEP-10. The respective uncertainty isan expanded uncertainty, ±U, with a coverage factor, k, equal to 2.

ElementReference value

Amount content ± U

in mmol·kg-1

Method applied Referencevalue is

As 0.128 3 ± 0.007 6 k0-NAA Assigned

Br 3.50 ± 0.30 k0-NAA Assigned

Cd 1.065 ± 0.056 IDMS Certified

Cl 8.01 ± 0.86 k0-NAA Assigned

Cr 1.94 ± 0.11 IDMS Certified

Hg 0.044 ± 0.013 IDMS Certified

Pb 0.470 ± 0.021 IDMS Certified

S 6.4 ± 1.3 k0-NAA,IC,ICP Assigned

2.4 Data collection and evaluation

All results were reported in the same unit (µmol·kg-1). From the questionnaire, it could be concluded

that the majority of participants analysed the sample under routine conditions. . About 70 % of the

participants analyse less than 25 samples of this type a year. From the 8 elements under investigation

in this IMEP-10 round, the participants were free to measure the content of those elements only

which were of interest to their laboratory Twenty one participants are measuring routinely less than

5 elements in this matrix and 11 participants are normally measuring up to 10 elements. In IMEP-10

toxic elements as cadmium, chromium and lead have been measured by almost all participants.

Some participants reported values for the same element obtained by different methods and these

values were inserted in the database as different results. For graphical presentation, the methods

have been grouped as shown in table 3. The number of participants for each element and method is

given in table 4.

Table 3 Grouping of the analytical methods used by participants in IMEP-10

Method Acronym Methodgroup

Cold Vapour-atomic absorption spectrometry CV-AAS CV-AASElectrothermal atomic absorption spectrometry ETAASGraphite furnace atomic absorption spectrometry GF-AAS

ET-AAS

Flame atomic absorption spectrometry FAAS F-AASFlame atomic absorption spectrometry-Mercury/HydrideSystem

FAAS-MHS

Flow injection analysis system-atomic absorption spectrometry FIAS-AASHydride-atomic absorption spectrometry H-AAS

F-AAS-Hydride

Ion chromatography IC ICInductively coupled plasma-atomic emission spectrometry ICP-AESInductively coupled plasma-optical emission spectrometry ICP-OES

ICP-ES

High resolution - inductively coupled plasma - massspectrometry

HR-ICP-MS

Inductively coupled plasma-mass spectrometry ICP-MSICP-MS

Isotope dilution-inductively coupled plasma-mass spectrometry ID-ICP-MS ID-ICP-MS

Infrared spectrometry IRInfrared / Leco furnace IR/Leco

IR

Coulometric analysis COUDifferential pulse polarography DPPFlame atomic fluorescence spectrometry FAFSGold amalgamator / UV-detection GAUVIon selective electrode ISENeutron-activation analysis NAAX-ray fluorescence XRFOther OTHER

OTHER

Table 4. Number of participants for the various methods and elements

ElementsMethod As Br Cd Cl Cr Hg Pb SCV-AAS 4ET-AAS 5 4 5 1 9F-AAS 11 7 1 8

F-AAS-Hydride 5 5IC 5 6 3

ICP-ES 3 9 10 1 7 1ICP-MS 10 3 10 1 11 7 10

ID-ICP-MS 1 1IR 2

OTHER 2 3 3 2 2 5 1 4Number of

results25 11 38 9 35 24 36 10

Based on the answers given in the questionnaire, the results obtained for each element are grouped

according to the following criteria e.g. degree of the laboratories’ self-declared experience,

accreditation -authorisation -certification status of the laboratory for the element under

investigation and the use of a quality assurance system. For each set of data, the results are

plotted together with the reference range and all results are included in the graphs. The scale of the

graphs, ± 50 % deviation from the middle of the reference range is chosen for convenience. All

results outside this range are presented in textboxes on the graph. Only for the element lead, the

scale was slightly modified to +20%/-100% deviation from the middle of the reference range. Table

5 gives a summary of the graphs which can be found in annex. In annex the graphs are presented

per element. The regional Swiss graphs are presented as a separate selection.

Table 5. Overview of IMEP-10 graphs presented in this report

Graph As Br Cl Cr Cd Hg Pb S

Experience: All to experience x x x x x x x xExperience x x x x xLess experience x x x x xSwitzerland toexperience

x x x x x x x x

Accreditation: All to accreditation x x xAccredited x x x xNon-accredited x x x x

Authorisation: All to authorisation xAuthorised x xNon-authorised x x

Certification: All to certification x x xCertified x xNon-certified x x

Methods: All to methods x x x x x x x xQualityassurance

ISO9000 x x x x x

EN 45000, ISO25 x x x x x xOther x x x

Use of H2SO4 x

It is a characteristic of IMEP that the participating laboratories draw their own conclusions.

However, as a general comment, it seems that for many elements the content reported is low. This

might be explained by the difficulties in digesting this material. Our experience showed that

microwave procedures, often used for this purpose, do not guarantee complete digestion. As for the

choice of acids used in the digestion, one third of the participants use digestion mixtures containing

sulfuric acid. However, Pb can precipitate as the suphate leading to lower contents. In annex, a

graphical display of the results with indication of sulfuric acid use is added. Validation of procedures

for trace elements in plastics is not easy since no reference materials are available, except the VDA-

polyethylene reference materials which are certified for Cd (IMEP-2 [7]). Two participants used

this VDA-reference material for validation purposes and both reported Cd results overlap with the

IMEP-10 Cd reference range.

Acknowledgements

IMEP runs under the support and auspices of IUPAC, EURACHEM, EUROMET and CITAC.

For this IMEP-10 round, the authors would like to express their gratitude to Dr. A. Lamberty, Dr.

G. Kramer, Dr. W. Van Borm (DSM-The Netherlands), Dr. A. Dobney., Mrs. B. Dijckmans, Dr.

H. Felber (EMPA-Switzerland), Dr. K.H.Grobecker, Dr. P. Robouch, Dr. G. Arana, Mrs. I. Dams

and Prof. P. De Bièvre for all the advise, help and assistance they offered throughout this project.

References

1. Comité Consultatif pour la Quantité de Matière (CCQM), Report of the 1st Meeting, ed. By BIPM, Sèvres, Cedex, France 1995.2. Project SMT4-CT95-2034, PERM, Progress report 1, Part A, by Dr. W. Van Borm, DSM Research, Geleen, The Netherlands.3. F. De Corte, L. Moens, S. Jovanovic, A. Simonits and A. De Wispelaere, J. Radioanal. Nucl. Chem., 1986, 102, 37.4. A. Dobney, Internal report, GE/R/SIM/50/975. Guide to the Expression of Uncertainty in Measurement, ISO, Geneva, 1993.6. Quantifying Uncertainty in Analytical Measurement, EURACHEM Secretariat, Queens Road, Teddington, Middlesex, TW11 0LY, England, 1995.7. A. Lamberty, P. De Bièvre and A. Götz, Fresenius J. Anal. Chem (1993)345 : 310-313

As• All reported results arranged in ascending order (self-declared

experience indicated)

• Results from experienced laboratories (self-declaration)

• Results from less-experienced laboratories (self-declaration)

• All reported results arranged according to the analytical methodused

• Results from participants in compliance with EN4500 and/orISO 25 (self-declaration)

• Results from participants in compliance with ISO 9000 (self-declaration)

0.064

0.079

0.094

0.109

0.124

0.139

0.154

0.169

0.184

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

Experienced laboratory (self-declaration)Less experienced laboratory (self-declaration)Non experienced laboratory (self-declaration)No statement by laboratory

As

Results from all participants.

IMEP- 10 : Trace Elements in Polyethylene Assigned range [U =k ·u c (k =2)]: 0.1207 - 0.1359 mmol·kg-1

Less experiencedAmount content Uncertainty Deviation

(in %)0.0136 0.0009 -89

0.064

0.079

0.094

0.109

0.124

0.139

0.154

0.169

0.184

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

As

Results from experienced (self-declaration) participants.


0.064

0.079

0.094

0.109

0.124

0.139

0.154

0.169

0.184

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

As

Results from less experienced (self-declaration, including no statement and non-experienced) participants.


Amount content Uncertainty Deviation

(in %)0.0136 0.0009 -89

0.064

0.079

0.094

0.109

0.124

0.139

0.154

0.169

0.184

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

ET-AAS F-AAS-HYDRIDE ICP-MS ICP-ES OTHERAs

Results from all participants, arranged by methods.


Method Amount content Uncertainty Deviation

(in %)F-AAS-Hydride 0.0136 0.0009 -89

0.064

0.079

0.094

0.109

0.124

0.139

0.154

0.169

0.184

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

As

Results from participants in compliance with EN45000 and/or ISO25 (self-declaration).



(in %)0.0136 0.0009 -89

0.064

0.079

0.094

0.109

0.124

0.139

0.154

0.169

0.184

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

As

Results from participants in compliance with ISO9000 (self-declaration).


Br• All reported results arranged in ascending order (self-declared





• All reported results arranged in ascending order (self-declaredaccreditation status indicated)


1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

5.25

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

Experienced laboratory (self-declaration)

Less experienced laboratory (self-declaration)Br



Less experiencedAmount content

< 0.25

1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

5.25

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %Br



1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

5.25

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %Br

Results from less experienced (self-declaration) participants.


Amount content< 0.25

1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

5.25

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

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d ra

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in %

ICP-MS IC OTHERBr



Method Amount content

IC < 0.25

1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

5.25

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

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d ra

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in %Br



Amount content< 0.25

1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

5.25

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

Accredited laboratory (self-declaration)

Non accredited (self-declaration) or no statementBr



AccreditedAmount content

< 0.25

Cd• All reported results arranged in ascending order (self-declared





• Results from accredited laboratories (self-declaration)

• Results from non-accredited laboratories (self-declaration)

• Results from authorised laboratories (self-declaration)

• Results from non-authorised laboratories (self-declaration)

• Results from certified laboratories (self-declaration)

• Results from non-certified laboratories (self-declaration)



• Results from participants operating quality systems other thanEN4500, ISO 25 and/or ISO9000(self-declaration)

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

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cer

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d ra

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in %


Cd


IMEP- 10 : Trace Elements in Polyethylene Certified range [U =k ·u c (k =2)]: 1.009 - 1.121 mmol·kg-1


(in %)0.041 0.001 -960.373 0.088 -65

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

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n fr

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cer

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d ra

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in %

Cd



0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

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cer

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d ra

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in %

Cd




(in %)0.041 0.001 -960.373 0.088 -65

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

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cer

tifie

d ra

nge

in %

.ET-AAS F-AAS ICP-MS ID-ICP-MS ICP-ES OTHERCd




(in %)F-AAS 0.373 0.088 -65

ICP-MS 0.041 0.001 -96

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Cd

Results from accredited (self-declaration) participants.



(in %)0.041 0.001 -960.373 0.088 -65

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Cd

Results from non accredited (self-declaration, including those with no statement) participants.


0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Cd

Results from non-authorised (self-declaration, including those with no statement) participants.



(in %)0.041 0.001 -960.373 0.088 -65

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Cd

Results from authorised (self-declaration) participants.


0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Cd

Results from certified (self-declaration) participants.



(in %)0.041 0.001 -960.373 0.088 -65

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Cd

Results from non-certified (self-declaration, including those with no statement) participants.


0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cd



Amount content Uncerta inty Deviation

(in %)0.041 0.001 -960.373 0.088 -65

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cd




(in %)0.041 0.001 -960.373 0.088 -65

0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cd

Results from participants operating quality systems other than EN45000, ISO25 and/or ISO9000 (self-declaration).


Cl• All reported results arranged in ascending order (self-declared




• All reported results arranged in ascending order (self-declaredcertification status indicated)

4.01

4.76

5.51

6.26

7.01

7.76

8.51

9.26

10.01

10.76

11.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

Experienced laboratory (self-declaration)Less experienced laboratory (self-declaration)

Cl



4.01

4.76

5.51

6.26

7.01

7.76

8.51

9.26

10.01

10.76

11.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

ICP-MS IC OTHERCl



4.01

4.76

5.51

6.26

7.01

7.76

8.51

9.26

10.01

10.76

11.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

Accredited laboratory (self-declaration)Non accredited (self-declaration) or no statement

Cl



4.01

4.76

5.51

6.26

7.01

7.76

8.51

9.26

10.01

10.76

11.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

Certified laboratory (self-declaration)Non certified (self-declaration) or no statement

Cl



Cr• All reported results arranged in ascending order (self-declared







• All reported results arranged in ascending order (self-declaredauthorisation status indicated)





0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %


Cr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

ET-AAS F-AAS ICP-MS ICP-ES OTHERCr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cr

Results from non-accredited (self-declaration, including those with no statement) participants.


0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Authorised laboratory (self-declaration)

Non authorised (self-declaration) or no statementCr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Certified laboratory (self-declaration)

Non certified (self-declaration) or no statementCr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cr



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Cr



Hg• All reported results arranged in ascending order (self-declared








0.022

0.027

0.032

0.037

0.042

0.047

0.052

0.057

0.062

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Experienced laboratory (self-declaration)Less experienced laboratory (self-declaration)No statement by laboratory

Hg




(in %)0.0698 0.0035 59

Non experiencedAmount content Uncertainty Deviation

(in %)0.01 0.02 -77


(in %)0.0216 0.0002 -51

0.022

0.027

0.032

0.037

0.042

0.047

0.052

0.057

0.062

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

ET-AAS F-AAS CV-AAS F-AAS-HYDRIDE ICP-MS ICP-ES OTHERHg




(in %)F-AAS-Hydride 0.0216 0.0002 -51

ICP-MS 0.01 0.02 -77


(in %)F-AAS-Hydride 0.0698 0.0035 59

0.022

0.027

0.032

0.037

0.042

0.047

0.052

0.057

0.062

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Hg



0.022

0.027

0.032

0.037

0.042

0.047

0.052

0.057

0.062

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Hg

Results from non-accredited (self-declaration) participants.



(in %)0.0698 0.0035 59


(in %)0.01 0.02 -77

0.0216 0.0002 -51

0.022

0.027

0.032

0.037

0.042

0.047

0.052

0.057

0.062

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Hg




(in %)0.0698 0.0035 59


(in %)0.0216 0.0002 -51

0.022

0.027

0.032

0.037

0.042

0.047

0.052

0.057

0.062

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Hg




(in %)0.01 0.02 -77

0.022

0.027

0.032

0.037

0.042

0.047

0.052

0.057

0.062

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Hg



Pb• All reported results arranged in ascending order (self-declared

experience indicated) (Y-axis = ± 50 % deviation from middleof certified range)

• All reported results arranged in ascending order (self-declaredexperience indicated) (Y-axis = +20/-100 % deviation frommiddle of certified range)

• Results from experienced laboratories (self-declaration)(Y-axis = ± 50 % deviation from middle of certified range)

• Results from experienced laboratories (self-declaration)(Y-axis = +20/-100 % deviation from middle of certified range)

• Results from less-experienced laboratories (self-declaration)(Y-axis = ± 50 % deviation from middle of certified range)

• Results from less-experienced laboratories (self-declaration)(Y-axis = +20/-100 % deviation from middle of certified range)

(Y-axis of graphs = +20/-100 % deviation from middle ofcertified range.)

• All reported results arranged in ascending order (use of sulfuricacid during the destruction procedure indicated)




• Results from authorised laboratories (self-declaration)

• Results from non-authorised laboratories (self-declaration)

• Results from certified laboratories (self-declaration)

• Results from non-certified laboratories (self-declaration)

0.24

0.29

0.34

0.39

0.44

0.49

0.54

0.59

0.64

0.69

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %


Pb



ExperiencedAmount content Uncertainty Deviation

(in %)0.0676 0.0203 -86

0.179 0.012 -62


(in %)0.035 0.005 -93

0.1972 0.0125 -580.214 0.036 -540.222 0.0133 -53

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %


Pb



0.24

0.29

0.34

0.39

0.44

0.49

0.54

0.59

0.64

0.69

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Pb




(in %)0.0676 0.0203 -86

0.179 0.012 -62

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Pb



0.24

0.29

0.34

0.39

0.44

0.49

0.54

0.59

0.64

0.69

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Pb

Results from less experienced (self-declaration, including non-experienced and no statement) participants.



(in %)0.035 0.005 -93

0.1972 0.0125 -580.214 0.036 -540.222 0.0133 -53

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Pb

Results from less experienced (self-declaration, including non-experienced and no statement) participants.


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

ET-AAS F-AAS ICP-MS ID-ICP-MS ICP-ES OTHERPb



0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

Use of Sulfuric acid for matrix destruction

No use of sulfuric acid for matrix destruction

Pb



0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Pb



0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Pb

Results from non accredited (self-declaration, including those with no statement) participants.


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Pb

Results from authorised (self-declaration) participants.


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Pb

Results from non authorised (self-declaration, including those with no statement) participants.


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Pb

Results from certified (self-declaration) participants.


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

c

m

mol

·kg-1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %

.Pb

Results from non certified (self-declaration, including those with no statement) participants.


S• All reported results arranged in ascending order (self-declared







3.2

4.0

4.7

5.5

6.2

7.0

7.7

8.5

9.2

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %


S



Less ExperiencedAmount content

< 15.6


(in %)1.329 7.89 -79

3.2

4.0

4.7

5.5

6.2

7.0

7.7

8.5

9.2

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

ICP-ES IC OTHERS




(in %)IR 1.329 7.89 -79

Method Amount content

IR <15.6

3.2

4.0

4.7

5.5

6.2

7.0

7.7

8.5

9.2

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

Accredited laboratory (self-declaration)Non accredited (self-declaration) or no statement

S



Non accreditedAmount content

< 15.6

AccreditedAmount content Uncertainty Deviation

(in %)1.329 7.89 -79

3.2

4.0

4.7

5.5

6.2

7.0

7.7

8.5

9.2

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %

Certified laboratory (self-declaration)

Non certified (self-declaration) or no statement

S



CertifiedAmount content Uncertainty Deviation

(in %)1.329 7.89 -79

Non certifiedAmount content

< 15.6

3.2

4.0

4.7

5.5

6.2

7.0

7.7

8.5

9.2

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %S




(in %)1.329 7.89 -79

3.2

4.0

4.7

5.5

6.2

7.0

7.7

8.5

9.2

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %S



Regional : Switzerland• As : all reported results arranged in ascending order (self-

declared experience indicated)

• Br : all reported results arranged in ascending order (self-declared experience indicated)

• Cd : all reported results arranged in ascending order (self-declared experience indicated)

• Cl : all reported results arranged in ascending order (self-declared experience indicated)

• Cr : all reported results arranged in ascending order (self-declared experience indicated)

• Hg : all reported results arranged in ascending order (self-declared experience indicated)

• Pb : all reported results arranged in ascending order (self-declared experience indicated)

• S : all reported results arranged in ascending order (self-declared experience indicated)

0.064

0.079

0.094

0.109

0.124

0.139

0.154

0.169

0.184

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %


As

Results from Swiss participants.


1.75

2.00

2.25

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

5.00

5.25

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %


Less experienced laboratory (self-declaration)Br



0.53

0.61

0.68

0.76

0.83

0.91

0.98

1.06

1.13

1.21

1.28

1.36

1.43

1.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %


Less experienced laboratory (self-declaration)

Cd



4.01

4.76

5.51

6.26

7.01

7.76

8.51

9.26

10.01

10.76

11.51

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %


Less experienced laboratory (self-declaration)

Cl



0.97

1.12

1.27

1.42

1.57

1.72

1.87

2.02

2.17

2.32

2.47

2.62

2.77

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %


Cr



0.022

0.027

0.032

0.037

0.042

0.047

0.052

0.057

0.062

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %


Hg



0.24

0.29

0.34

0.39

0.44

0.49

0.54

0.59

0.64

0.69

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

cer

tifie

d ra

nge

in %


Pb




Uncertainty Deviation (in %)

0.1972 0.0125 -58

3.2

4.0

4.7

5.5

6.2

7.0

7.7

8.5

9.2

c

m

mol

·kg-1

-50

-40

-30

-20

-10

0

10

20

30

40

50

Dev

iatio

n fr

om m

iddl

e of

ass

igne

d ra

nge

in %


Less experienced laboratory (self-declaration)S




(in %)1.329 7.89 -79


< 15.6

Appendix• REPORT FORM

• QUESTIONNAIRE

International Measurement Evaluation Programme: IMEP9, trace elements in water

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Transcript of International Measurement Evaluation Programme: IMEP9, trace elements in water