requirement cu - rm.ume.tubitak.gov.tr · jochen v. maren k. dorit b. pranee p. quantification of...
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Jochen V.
Maren K.
Dorit B.
Pranee P.
Quantification of in copper metals sulfurand its alloys by ICP-IDMS
1,2,3 1 1 1,2P. Phukphatthanachai , J. Vogl , N. Jakubowski , U. Panne1BAM Federal Institute for Materials Research and Testing, Berlin, Germany2Humboldt University, Berlin, Germany3National Institute of Metrology (Thailand), Pathum Thani, Thailand
Requirement
SApplications: Certification of reference materials
Purity assessment
Reference value assignment for inter-laboratory comparisons
Calibration of other analytical methods
9. Matrix removal efficiency 99.999 %
Sulfur recovery > 80 %
8. Separation 3: Chelating resin
(Chelex-100)
More detail: JAAS, 2017, DOI: 10.1039/C7JA00338B
10. Instrument: Element 2
(Thermo-Fisher Scientific)
- Medium resolution > 4000
- Ni sampler and skimmer X-cone-1- Background 30-48 ng·g
7 32 -1- Sensitivity 1x10 for S cps/(µg·g )
7. Separation 2: Strong anion exchange resin
(AG1X8)
6. Separation 1: Cation exchange resin
(CG50)
5. Digestion:34- Spike isotope: S
- Dissolution in nitric acid - Digestion in high pressure asher (HNO + H O )3 2 2
2. Copper: essential and
important to industy
INT
RO
DU
CT
ION
EX
PE
RIM
EN
T:
sulf
ur-
mat
rix
sep
arat
ion
RE
SU
LTS
AN
D C
ON
CLU
SIO
N
CuSIsotope composition
(IUPAC 2000)32 S 0.9499(26)33 S 0.0075(2)34 S 0.0425(24)36 S 0.0001(1)
16
32.065
3.Sulfur:
a key factor in quality of copper metals and its alloys
Ion
inte
nsi
ty (
arb.
un
its) Sample Spike
32S 32S34S 34S
Ion
inte
nsi
ty (
arb.
un
its)
32S34
S
Sample blend
clear solution
weak cation resin (CG50)
before after
w = w M m (R - R ) - ProcBlankx yb x y y xy
M m a (R - R ) mb x xb xy x x
w = mass fraction of sulfur in the sample (mg )x
-1·g
w = mass fraction of sulfur in the spike (mg ) yb
-1·g
M = standard atomic weight of sulfur in samplex
M = atomic weight of spike isotopeb
a = abundance of spike isotope in samplexb
m = mass of sample (g)x
m = mass of spike (g)y
R = isotope ratio in samplex
R = isotope ratio in spikey
R = isotope ratio in sample blendxy
ProcBlank = procedure blank (mg)11. IDMS equation
1. Limitations of current techniques: Lack of metrological traceability
Inconsistent results
High relative measurement
uncertainty (> 5 %)
High background
Polyatomic interferences
High detection limit
High matrix concentration
4. IDMS (Isotope Dilution Mass Spectrometry)
- High accuracy- Metrological traceability- Small measurement uncertainty
- High accuracy
- Traceable to SI
- Small measurement uncertainty
<1 % RMU
- High matrix removal efficiency 99.999 %
- High sulfur recovery > 80 %
- Low procedure blank (4-53 ng)
- LOD 0.2 -1 -1µg·g , LOQ 0.54 µg·g
- Working range (15-1500 )-1µg·g
12. Results (sulfur in copper CRMs)
SI
Mass fraction of sulfur in copper samples, ICP-IDMS
Secondary calibrator, 34S isotope standard, IDMS
Primary calibrator, NIST3154, gravimetric and coulometric titration
List BAM-M385 BAM-M376a BAM-228 BAM-227 NIST SRM494
-1measured value (µg·g ) (37.7 ± 0.2) (133.6 ± 0.9) (385.5 ± 2.4) (1,376.6±0.1) (14.3±0.1)
U (%)rel 0.5 0.6 0.6 0.5 0.7
-1reference value (µg·g ) (31.2 ± 1.5) (133 ± 19) 360 ± 40 1,220±100 (15 ± 3)
-1Cu remaining (ng·g ) < 100 < 150 < 100 < 150 < 150
number of replicates 8 8 8 8 4
13. Conclusion