Results of the 18 th and 19 th Needle/Leaf Interlaboratory ...e7...Results of the 18 th and 19 th...
Transcript of Results of the 18 th and 19 th Needle/Leaf Interlaboratory ...e7...Results of the 18 th and 19 th...
Results of the 18 th and 19th Needle/LeafInterlaboratory Comparison Tests
Meeting of the Working Group QA/QC in Laboratories
Zagreb/Croatia March 2017
Alfred FÜRST
Overview
• General information about both tests• Main Results• Common methods• Problematic parameters/laboratories• Re-qualification after the 18th Test• Reference samples• Ongoing foliage ringtest program• Enlarge parameter list (heavy metals)
Countries/LaboratoriesInterlaboratory
Comparison TestNumber
of countriesNumber of
laboratories
5th
29 53
6th
26 46
7th
23 43
8th
30 52
9th
28 53
10th
29 54
11th
28 56
12th
30 56
13th
29 60
14th
28 62
15th
28 61
16th
25 57
17th
25 54
18th
25 53
19th
22 45
Participating labs decreasing
• Stop funding of the monitoring program
• Participating only in uneven years -
paralell to the monitoring activities
• Closing and/or merging of labs
• Costs of the ringtest…
240€ are too expensive?
= 7 l nitric acid 65% = 100 ml multielement standard= one PTFE vessel for microwave digestion= 4 working hours of a lab worker
And how expensive are wrong results??
Comparison between 7 th and 19 th
Interlaboratory Comparison TestElement 7 th Test 2004/05 (Sample 1) 19 th Test 2016/17 (Sample 4)
(Unit) Mean Number of Labs Mean Number of Labs
N 17.01 17.17
mg/g 39 38
S 1.09 1.12
mg/g 39 37
P 1.89 1.93
mg/g 41 41
Ca 2.63 2.70
mg/g 41 42
Mg 0.92 0.94
mg/g 41 42
K 5.83 5.82
mg/g 42 42
C 51.61 52.13
g/100g 29 34
Comparison between 7 th and 19 th
Interlaboratory Comparison TestElement 7 th Test 2004/05 (Sample 1) 19 th Test 2016/17 (Sample 4)
(Unit) Mean Number of Labs Mean Number of Labs
Zn 41.73 41.72
µg/g 36 33
Mn 183.6 183.1
µg/g 35 34
Fe 36.81 36.86
µg/g 34 32
Cu 3.13 3.03
µg/g 31 33
Pb 0.21 0.17
µg/g 15 26
Cd 78.63 75.42
ng/g 20 24
B 5.98 5.09
µg/g 21 18
Difficult Samples & Elements
18th Test
1. Beech Leaves� + B � - Pb
2. Pine Branches� + Fe, Cd� - N, S, P, Ca, Mg, K, B
3. Spruce Needles� - Pb
4. Spruce Needles� - Pb
19th Test
1. Spruce Needles� - Pb
2. Spruce Needles� - Pb
3. Spruce Needles� + Zn, Pb, Cd
4. Pine Needles� - Ca, B, Pb
too low content for evaluation
Percentage of non tolerable results in Needle/Leaf samples
0
5
10
15
20%
S P Ca Mg K N
Labs failed with the same element/s in both tests
• Germany A59 (C)• Germany A79 (Mg)• Germany A80 (Zn)• ICP-Forests lab - Croatia A62 (Ca, Mg)• ICP-Forests lab - Spain F33 (Fe)
What influences data quality ? Results of the questionaire
• Laboratory accreditation• Higher number of analyzed samples/a• Control charts• Staff trained on the method/matrix• More than one ringtest participations/a
Pretreatment methods 2016/17Element
open
digestion
pressure
digestion microwave
dry
ashing pellet
no or other
pretreatment
N 9 29
S 3 7 16 2 9
P 8 7 21 2 3
Ca 9 8 21 2 2
Mg 9 7 22 2 2
K 9 8 21 2 2
C 1 1 32
Zn 3 7 20 2 1
Mn 3 7 21 2 1
Fe 2 6 21 2 1
Cu 3 6 21 2 1
Pb 1 7 18
Cd 1 7 16
B 1 3 13 1
Changes in pre-treatment methods
from 2006 till 2017
• N: open digestion � no digestion(element analyzers)
• Dry ashing � open digestion (P, K, Ca, Mg, Mn) or to microwave
• Pressured digestion � microwave
Determination methods 2016/17Element
Element-
analyzer
Flame-AAS
& AES Flameless-AAS ICP-AES ICP-MS other
N 29
9 (Kjeldahl)
1 (UV-VIS)
S 7 24 3 3 (X-Ray)
P 28 3
3 (X-Ray)
7 (UV-VIS)
Ca 8 28 3 3 (X-Ray)
Mg 8 28 3 3 (X-Ray)
K 9 27 3 3 (X-Ray)
C 32 1
Zn 1 21 8 3 (X-Ray)
Mn 3 23 5 3 (X-Ray)
Fe 1 23 5 3 (X-Ray)
Cu 1 20 9 3 (X-Ray)
Pb 3 10 13
Cd 4 8 12
B 14 4
Changes in determination methods
from 2006 till 2017
• N: „Kjeldahl method“ � Element analyzers
• Flame-AAS � ICP-AES• Flameless AAS � ICP-MS• ICP-AES � ICP-MS
Element Tolerable 17th
Labtest 18th
Labtest 19th
Labtest
limits 2014/2015 2015/2016 2016/2017
(± %) Non Number of mean values
Non Number ofmeanvalues
Non Number of mean values
tolerable tolerable tolerable
(%) (%) (%)
N 10 2.1 192 7,9 164 4,6 152S 15 9.9 192 6,4 156 7,4 148P 10 14.7 204 15,5 168 15,4 164
Ca 10 17.7 212 9,1 176 11,3 168Mg 10 12.3 212 14,2 176 13,1 168K 10 11.5 208 15,6 180 16,7 168C 5 7.8 180 9,5 148 8,1 136Zn 15 8.1 172 13,5 148 12,1 132Mn 15 3.9 180 6,1 148 8,8 136Fe 20 6.5 168 12,2 148 13,3 128Cu 20 15.7 172 4,2 144 15,2 132Pb 30 7.8 87 16,0 75 7,7 24Cd 30 14.3 112 8,0 112 2,1 96
B 20 5.0 100 11,9 84 13,9 72
+
Compare your results from thelast tests - what happend?
N S P Ca Mg K C Zn Mn Fe Cu Pb Cd B
16th Test >
17th Test >> >
18th Test >> > <>> <> <>>
19th Test > << < < < < >>>> < <<<<
• C, N (other element analyzer)• Pressure digestion / ICP-MS• Always problems with Fe! What is with B in the last test?•„Is no accredited testing laboratory“• „Lab uses a mean, a range and a blank control chart“
� and check nothing?• „100-500 plant samples/a“• „Good trained staff on the method/analytical equipment“
Compare your results from thelast tests - what happend?
N S P Ca Mg K C Zn Mn Fe Cu Pb Cd B
16th Test >
17th Test >> >
18th Test >> > <>> <> <>>
19th Test > << < < < < >>>> < <<<<
• C, N (other element analyzer)• Pressure digestion / ICP-MS• Always problems with Fe! What is with B in the last test?•„Is no accredited testing laboratory“• „Lab uses a mean, a range and a blank control chart“
� and check nothing?• „100-500 plant samples/a“• „Good trained staff on the method/analyticalequipment“
Compare your results from thelast tests - what happend?
N S P Ca Mg K C Zn Mn Fe Cu Pb Cd B
17th Test > >> >> <<< >>> >>> > >>>> >
18th Test < <<<<
19th Test << >>>> >>>> >>>> >>>> >>>> <<<< >>>> >>>> >>>> >>>> >>>>
• C is always too low(Element analyzer) – no improvement• Open digestion method & ICP-AES � contamination?• Changes in the laboratory staff? Wrong samples?• „No accredited testing laboratory“• „Lab uses a mean chart and blank chart“ � and check nothing?• „1000-5000 samples/a“ �50-250 correct analyzed samples!• „Good trained staff on the method/analytical equipment“
Compare your results from thelast tests - what happend?
N S P Ca Mg K C Zn Mn Fe Cu Pb Cd B
17th Test > >> >> <<< >>> >>> > >>>> >
18th Test < <<<<
19th Test << >>>> >>>> >>>> >>>> >>>> <<<< >>>> >>>> >>>> >>>> >>>>
• C is always too low(Element analyzer) – no improvement• Open digestion method & ICP-AES � contamination?• Changes in the laboratory staff? Wrong samples?• „No accredited testing laboratory“• „Lab uses a mean chart and blank chart“ � and check nothing?• „1000-5000 samples/a“ �50-250 correct analyzed samples!• „Good trained staff on the method/analytical equipment“
What is a good result?Accuracy of the mean & precision
% Recovery 97.79 – 99.93% Vi 0.60-1.17%
% Recovery 86.22 – 131.2% Vi 2.97-7.89%
What is a good result?
• % Recovery close to 100% with a smallvariation between the four sample results(= your method is under control)
• Vi (variation between the replicates)– element analyzer (measurement without
extra sample preparation) < 3%– Macro elements (P, K, Ca, Mg, K) < 5%– Micro elements and heavy metals < 10%– Trace elements < 20%
Reasons for Re -Qualificationafter the 18th Needle/Leaf Ringtest
• Technical problem / no servicing of the instrument (5 labs)
• Calibration error (one lab)• Methodical problem / method changed
(one lab)• Missed data submission deadline or got
no samples (one lab)• No dry matter correction (one lab)
Re-Qualification after the19th Needle /Leaf Ringtest
• Is mandatory for all „ICP-Forestslaboratories “ if they plan to:
• Submit monitoring results from thesampling period 2016/17 to the PCC database („growing saison “ 2016)
• Deadline 1 st September 2017
Re-Qualification
• Use in all communications your lab code number
• Use in any case the xls-form for your re-qualification: http://bfw.ac.at/rz/bfwcms2.web?dok=7830
• Submit all printouts. calibration. dilution factors .… (= I should be able to recalculate your results!)
• What was the reason (or your opinion) for missing the qualification?
• Think on m easures to avoid errors in future!
FFCC offers reference materials
• Spruce needles A• Maple leaves A • Litterfall (beech leaves)• Pine needles (Pinus nigra)• Spruce needles B (+heavy metals )
http://bfw.ac.at/rz/bfwcms2.web?dok=5146www.ffcc.at
Element N/L Unit Mean SR
N 140/35 mg/g 14.20 0.376
S 136/34 mg/g 0.94 0.047
P 156/39 mg/g 2.01 0.121
Ca 160/40 mg/g 5.83 0.339
Mg 156/39 mg/g 1.07 0.058
K 156/39 mg/g 7.28 0.413
Zn 127/32 µg/g 32.70 2.574
Mn 128/32 µg/g 359.3 22.689
Fe 124/31 µg/g 73.73 8.568
Cu 128/32 µg/g 3.16 0.441
Pb 56/14 µg/g 0.08 0.034
Cd 76/19 ng/g 28.14 3.283
B 68/17 µg/g 12.06 1.320
C 135/34 g/100g 51.98 1.152
As 32/8 ng/g 20.53 4.957
Co 64/16 µg/g 0.29 0.020
Cr 88/22 µg/g 4.24 0.637
Hg 52/13 ng/g 28.27 6.501
Mo 32/8 ng/g 291.6 31.109
Ni 90/23 µg/g 2.26 0.268
Tl 24/6 ng/g 5.12 0.896
V 36/9 µg/g 0.063 0.008
Spruce needles B New
20th Needle /Leaf Interlaboratory Test 2017/18
http://bfw.ac.at/ws/ring_nadel.login
Statistical evaluation for heavy metals
Heavy metals Heavy metals
Enlarge parameter list
• Use of multielement methods (ICP-AES, ICP-MS) � no additional costs /time
• Ringtest participation (> 10 laboratories )
• Repetitious accuracy
Enlarge parameter list
Above the element symbol you can see the number of participants in the last test.
Element commonMethod
Number oflabs
„low“content
„high“content
Arsenic ICP-MS 13 41 ng/g79.6-119.4%
127 ng/g84.2-110.3%
Cobalt ICP-MS/(ICP-AES)
17 0.066µg/g67.1-130.1%
0.47µg/g75.4-113.3%
Chromium ICP-AES 23 0.863µg/g80.5-139.3%
4.24µg/g70.9-129.1%
Mercury ICP-MS / Element analyzer
14 31.5ng/g89.8-109.8%
70.6ng/g86.9-114.3%
Nickel ICP-AES 23 0.831µg/g80.1-120.9%
5.36µg/g80.8-115.6%
Element commonMethod
Number oflabs
„low“content
„high“content
Cadmium ICP-MS/GF-AAS
24 28.1ng/g85.3-127.8%
294ng/g81.8-117.7%
Lead ICP-MS/GF-AAS
26 0.43µg/g61.1-142.9%
27.1µg/g59.7-129.6%
Element commonMethod
Number oflabs
„low“content
„high“content
Arsenic ICP-MS 13 41 ng/g79.6-119.4%
127 ng/g84.2-110.3%
Cobalt ICP-MS/(ICP-AES)
17 0.066µg/g67.1-130.1%
0.47µg/g75.4-113.3%
Chromium ICP-AES 23 0.863µg/g80.5-139.3%
4.24µg/g70.9-129.1%
Mercury ICP-MS / Element analyzer
14 31.5ng/g89.8-109.8%
70.6ng/g86.9-114.3%
Nickel ICP-AES 23 0.831µg/g80.1-120.9%
5.36µg/g80.8-115.6%
Element commonMethod
Number oflabs
„low“content
„high“content
Cadmium ICP-MS/GF-AAS
24 28.1ng/g85.3-127.8%
294ng/g81.8-117.7%
Lead ICP-MS/GF-AAS
26 0.43µg/g61.1-142.9%
27.1µg/g59.7-129.6%
Thank you for your attention!