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Commissie voor Klinische BiologieCommission de Biologie Clinique
ETHANOL determination in blood
Dr Pharm HAMERS, Nicole
Rue Juliette Wytsmanstraat 14 | 1050 Brussels | BelgiumT +32 2 642 51 11 | F +32 2 642 50 01 | email: [email protected] | www.iph.fgov.be
2. External quality control ethanol
2 surveys / year
≥ 5 samples / survey
(+/- 150 participants)
Case reports for the experts (27)
“all laboratories will receive test items that:
do not differ significantly in the parameters to be measured
are sufficiently stable to ensure that they will not undergo any significant change throughout the conduct of the test.
EQA’s must be able to identify errors in testing, not have false warnings due to inhomogeneous or unstable samples!
STORAGE conditions before sending: freezer
In house preparations
- 80°C- + monitoring
One day before sending sample transfered to fridge 4 to 8°C
Day of sending: room temperature: Monitoring
CONTROL of the distribution: ethanol dosage in samples taken in the beginning, the middle and atend of the distribution procedure.
< 10CFU / mlCONTROL of the bacteriological contamination
? Quality of samples devoted to EQA’s Ethanol
n= 150 participants, volume: 2.0 mL
SamplesGenerally in house
Matrix used: 1992 to 1998/1• Physiological water: negative bias (- ~ 20%) with
Ektachem)• Horse blood : hemolysis problem• Bovine serum; positive bias with Emit• Plasma pool with LDH (±10.000U/L) and
lactate(15mmol/L) positive bias with Syva (+ ~20 à 40%)
1998/2 till today• Human plasma pools
Evolution of the methods from1992 to 2001
0
10
20
30
40
50
60
70
CasierDelaunois
Direct GC Head GC ADH AO TDx AxSym
1992
1997
2000
2001
% results
Evolution of the methodsfrom 2002 to 2008
0
5
10
15
20
25
30
35
40
45
50
CasierDelaunois
Di GCcap
Dir GCpack
Head GC Aeroset AxSym TDx SiemensAdvia
Beckman Emit Roche Sigma Vitros Dimension
2002200420062008
RD september 2007
% results 44%
12%8.5%
0.0g/L ethanol+ 0.5g/L methanol
n = 47 31 6 63 56 76
0
0,2
0,4
0,6
0,8
1
1,2
Casier Delaunois Dir gas chrom Head. gas chrom ADH AO TDx
Mediang/L
Ethanol 0.55 g/L
+ Methanol 0.5g/L
.2
.4
.6
.8
1
1.2
1.4
1.6
1.8
2
Casier Chr gaz ADH
,1
,2
,3
,4
,5
,6
,7
,8
,9
C C
asie
r
D C
asie
r
C G
CD
ir
D G
CD
ir
C H
eads
p
D H
eads
p
C A
DH
D A
DH
g/l
0.4 g/L 0.5 g/L
Global report
0
12
3
45
6
ADH (Hita
chi)
Direct
GCADH (V
itros)
ADH (Coba
s)
Heads
pace G
CADH (E
mit)REA(AxS
YM)Cas
ierREA (T
Dx)
4.9%
Casier
intra-laboratory precision
CV %
Relative accuracy for a result of 0.65g/L
valeur cible = Médianes de consensus NZDSMedian
192+ 50.020.55 g/LMethod
Individual report
Z score =R – M
DS consensus value: median of the group
Absolute accuracy for a result of 0.65g/L
U score=R – M
M target: median of al the results from all the chromatographic methods
U: fixed limitFor RD: error<0.1g/L- (21.6%<0.4g/L, 9.5% <0.7g/L, >0.7g/L 6.5%)For ISP: 25 %<0.4g/L - 15%>0.4g/L
Pz z= 3SD Pu ISP= 15%
0.65/0045
0.65/00418%
0.65/0411.8
0.65/04116%
Year report
Median: 0.55 ± 0.02
Median: 0.56 ± 0.05
Target: 0.55 g/L
0.410.46
0.510.56
0.610.66
0.71
M
σ σ 2σ 3σ 2σ 3σ
0.63
σ: 0.05 – CV: 9.8 %
0.47
0.490.510.53
0.550.570.590.61
M
σ σ 2σ 2σ 3σ 3σ
0.63
σ: 0.02 - CV: 4.1%
0.47
Headspace gas chromatography AxSym
Target: 0.55 g/L Pu ISP= 15%
Evolution of the Pz and PuRD scores from 2006 to 2008
0
5
10
15
20
25
30
35
40
45
50
mean P25 P50 P75 P90
Pz2006
Pz2007
Pz2008
PuRD2006
PuRD2007
PuRD2008
2008
0
20
40
60
80
100
120
0 20 40 60 80 100 120
Percentage z-scores and u-scores "out of limits"
Cum
ulat
ive
prop
ortio
n la
b's
(%)
Pz
PuRD
PuISP
15% citations
90%
CV’s per method for the 2 surveys of the 2008 EQA cycle
5%
0 2 4 6 8 10 12 14 16
Direct GC (pack.-col.)
Dimension
Headspace GC (cap.-col. )
Roche
GLOBAL
Vitros
Direct GC - (cap.-col.)
Emit
TDx
AxSym
CVmax(%)CVmed(%)CVmin(%)
(~n)
(8)
(8)(7)
(8)(20)
(75)
(14)
(10)
(9)
0,0
2,0
4,0
6,0
8,0
10,0
12,0
14,0
16,0
18,0
Pz PuISP2008 PuRD
Direct GC - (cap-col)Direct GC (packed-col)Headspace GC(cap-col )GLOB
% Citations per method
5%
n TOT= 119 161 263 2388 128 161 2495263
%
Direct GC cap - Direct GC packed - Headspace cap
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
40,0
Pz PuISP2008 PuRD
Aeroset/ Architect
AxSym
TDx
GLOB
5%
n TOT= 10 90 73 2388 25 96 249588
% Citations per method
%
ADH - Abbott - Aeroset - Axsym - TDx
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
Pz PuISP2008 PuRD
Roche
Dimension
Vitros
Emit
GLOB
5%
% Citations per method
ADH - Roche - Dimension - Vitros - Emit
n TOT= 1271096 293 2495134
%
Forensic experts for road safety
BEFORE 2007Royal Decree 10 june 1959
- Casier Delaunois (oxydo red.)- Experts nominated for lifewithout any special requirement exceptone inspection (IPH inspector) at the beginning of the activity- Chosen by the Public Prosecutor
AFTER june 2007RD started in september
Expert report: no back calculation
one expert answer 0.41g/L (0.09 g/L + 4x0.08)g/L. another answer « 0 to 0.79g/l ».
Back calculation
Analytical results: between 0 and 0.13g/L.
1. Sample without ethanolAccident at 10h. Blood taken at 15h.
Forensic experts for road safety
2. Sample with a median of 0.5g/L•Accident at 10h. Blood taken at 13h. (3x0.15)g/L•Driver (man 80Kg) declared 1 glas beer (Chimay 9°) taken at 12h. (-0.43g/L)
Back calculation (2004/1)
Analytical results: 0.34 to 0.67 g/L
With: 0 to 0.89 g/L
Without: 0.67 to 1.12 g/L
-,1
,1
,3
,5
,7
,9
1,1
Anal results With Without
Back calculation
Origin of the differences between results:
- metabolisation coefficient : imposed by public prosecutor: from 0.08 to 0.2 g/L / h
- some calculations > 6h even when the sampledid not contain ethanol....
Forensic experts for road safety
BEFORE 2007Royal Decree 10 june 1959
- Casier Delaunois (oxydo red.)- Experts nominated for lifewithout any special requirement exceptone inspection (IPH inspector) at the beginning of the activity- Chosen by the Public Prosecutor
AFTER june 2007RD started in september
- Gas chromatography-Experts
- validated method- Internal controls- External qual. assessment (IPH)
- Chosen by the Public Prosecutorin a list of experts complying to the RD requirements
Requirements of the Decree of june 2007
Standard operating procedure describing the analysis
Validation of the method •quantification limit•repeatability•reproductibility•linearity•bias (reference material)
Column : ethanol, aceton, methanol, isopropanol and internal standard
Back calculation
- If the mean of two determinations (-0.10g/L)=0.2g/L- Metabolisation coefficient
0.15g/L x 4h + 0.10g/L x 2h (maximum 6h)
SOP describing the expert’s report
Result taken in the final report:mean of the two analytical results – 0.10g/L
(correction of the uncertainty)
EQA’s for ethanol highlight- the impact of the external controls on the quality
of the routine analyses- the importance of the pedagogical role of the
EQA’s
Conclusion
Experts
CHARLIER C.TEL. :04/366.88.18FAX :04/366.88.89e-mail :[email protected] W.TEL. :09/264.81.35FAX :09/264.81.83 e-mail :[email protected] F.TEL. :056/24.25.30FAX :056/24.25.37e-mail
:[email protected] H.TEL. :03/217.78.04FAX :03/217.78.00e-mail :[email protected] E.TEL. :065/40.36.10FAX :065/34.74.80e-mail :etienne.noël @hainaut.beTYTGAT J.TEL016/32.34.03FAX :[email protected] V.TEL. :02/477.50.42FAX :02/477.50.47e-mail :[email protected] DAMME M.TEL. :02/650.51.97FAX :02/650.51.87e-mail :[email protected] A.TEL. :09/240.34.07FAX :09/240.49.85e-mail :[email protected] P.TEL. :02/764.67.20FAX :02/764.37.32e-mail
List of the forensic experts in Belgium
Available on the following adress:
http://www.iph.fgov.be/ClinBiol/bckb33/activities/alcool/Liste_des_experts_Lijst_van_experten.pdf
September 2006
Philippe Van de Walle Tel: 02 642 55 25 Fax: 02 642 56 45
E-mail: [email protected]
May 2010
IPH Team of Clinical Biology
