Validation of a Rapid Uranium in Urine by ICPMS Procedure

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• Validation of a Rapid Uranium in Urine by ICP-MS
  Procedure
• 54th Annual Radio-bioassay Radiochemical
  Measurements Conference
• Destin, Florida, October 2008

Lori Collins, Alfonso Gobaleza, Robert Langston,
Chit Than, Carolyn Wong Bioassay Laboratory, LLNL
Lawrence Livermore National Laboratory, P. O. Box
808, Livermore, CA 94551
This work performed under the auspices of the
U.S. Department of Energy by Lawrence Livermore
National Laboratory under Contract
DE-AC52-07NA27344
LLNL-PRES-407691
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Why do we need Validation ???

Analysis of Uranium in urine using ELAN 6000
Analysis of Uranium in urine using ELAN DRC-e
Under DOE-STD-1112-98 section 5.7.2 Technical
Equivalency has to be documented
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Uranium Standard Operation Procedure
1 mL Urine Blank
1 mL Urine Spike
0.1 ng U-238
5 ng U-233 For ELAN 6000
0.5 mL Ultra pure HNO3
1 mL Blind QC
1 ng U-233 For DRC-e
1 mL Reagent Blank DI water
Place in microwave sample rack
1 mL Urine sample
MARS 5 Digestion system
8.4 mL DI water
PerkinElmer ELAN DRC-e ICP-MS
Sample rack
10 min ramp to 85C Hold for 30 min
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BLAB Standard Operation Procedure for Uranium
Analysis

• Sequence with Analytical QC Samples

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BLAB Standard Operation Procedure for Uranium
Analysis

• ELAN 6000 ICP-MS Run List with Analytical and
  Instrument QC Samples

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Calibration and Quality Control Standards for
Uranium Analysis
IPC
Blank
RL
QCS
ELAN 6000
Blank
0.005
0.02
0.05
0.1
0.0
0.025
0.01
0.05
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
Blank
IPC
RL
QCS
DRC-e
0.1
0.0005
0.001
0.005
0.02
0.05
0.2
0.5
0.0
0.01
0.00025
0.02
Blank
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
?g/L
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Comparison of Operation Parameters for ELAN 6000
and DRC-e
ELAN DRC-e
ELAN 6000

• Use 9 calibration standards
• Internal standard (U-233) 0.1 ?g/L
• QCS 0.02 ?g/L
• IPC 0.01 ?g/L
• RL 0.00025 ?g/L
• Dwell time for U238 100 ms
• Sweep 100
• Integration time 10, 000 ms
• Replicates 3
• Auto lens OFF
• Detector Mode Pulse
• Data transfer Auto save to server

• Used 5 calibration standards
• Internal standard (U-233) 0.5 ?g/L
• QCS 0.05 ?g/L
• IPC 0.025 ?g/L
• RL 0.01 ?g/L
• Dwell time for U238 100 ms
• Sweep 50
• Integration time 5, 000 ms
• Replicates 2
• Auto lens OFF
• Detector Mode Pulse
• Data transfer Manual

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ELAN DRC-e Detection Limit (IDL)
5 HNO3 (Ultra Pure) in DI Water
Instrument Detection Limit 3 x S 0.00005
?g/L 0.05 ppt
Standard deviation (S) 1.6E-05 ?g/L
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Determination of Method Detection Limit (MDL)of
Uranium Analysis on ELAN DRC-e
Inter-analyst and inter-run

• Collected urine samples from individuals not
  occupationally exposed to uranium.
• Samples were spiked with varying amount of
  U-238.
• Analyzed by 4 chemists (2 replicates per
  analyst).
• Prepared 8 replicates for each concentration.
• Each series of spikes were analyzed
  separately.(instrument shut down and restarted
  next day)

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Determination of MDL99, MDA95 and LC95
MDL99 (tn-1,0.99) (S) 0.0033 ?g/L
MDA95 (2) (tn-1,0.95) (S) 0.0042
?g/L
LC95 (tn-1,0.95) (S) 0.0021 ?g/L
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Determination of Measurement Uncertainty of DRC-e
method
Combined standard uncertainty (CSU, 1?) CSU
0.0100 (?g/L 238U) 0.0005 R2 0.9952
?g/L 238U lt 0.1 ?g/L CSU 0.0015 ?g/L ?g/L
238U 0.1 ?g/L CSU 0.0100 (?g/L 238U)
0.0005 ?g/L
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Comparison between ELAN 6000 and ELAN DRC-e

• Single analyst

• Multi analyst
• Multi run

MDL99 0.0033
?g/L Performance Criteria for Radio-bioassay
Section 3.4 of N13.30
MDA95 0.0042 ?g/L LC
0.0021 ?g/L Required detection limit 0.01 ?g/L
MDL99 0.002 ?g/L Reporting
Limit RL 5 x MDL99 0.01 ?g/L
ELAN DRC-e
ELAN 6000
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Comparison of Results for ELAN 6000 versus ELAN
DRC-e
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Comparison of Results for ELAN 6000 versus ELAN
DRC-e(Oak Ridge National Laboratory Inter
Laboratory QC test samples)
A two-tailed paired t-test, at the 95 confidence
level, analysis of each of the two sets of data
give P values of 0.547 and 0.329 indicating that
the results are equivalent.
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Conclusions
LLNL Internal Dosimetry Program

• The new procedure satisfies the requirement to
  analyze for U-238 in bioassay samples.

MDA

• The LC and MDA95 are well below the required
  detection limit of 0.01 ?g/L.

Technical Equivalency

• The analytical results for ELAN DRC-e are
  technically equivalent to the ELAN 6000.

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• Our petition for
• Technical Equivalence between
• DRC-e ICP and ELAN 6000
• was approved by DOELAP
• on February 20, 2008