Determination of trace and ultra- trace elements by ICP-SFMS · 2018. 1. 15. · 238U 30 7 23 PtAr , HgAr HgCl TlCl, PbO 2 239Pu 0.03 0.08 0.25 UH, U tail , HgAr HgCl PbCl, PbO 2

RIGHT SOLUTIONS · RIGHT PARTNER

1


Determination of trace and ultra-trace elements by ICP-SFMS

Ilia Rodushkin, Emma Engström, Douglas Baxter

ALS Scandinavia AB

Luleå University of Technology


2

Luleå laboratory

Part of ALS group (>300 laboratories

worldwide)

Focus areas: ultra-trace multi-elemental

determinations and isotope ratio

measurements

>130 000 samples annually

Close co-operation with LTU resulting

in 200 publications


3

3 ICP-OES

14 ICP-SFMS

3 AFS

1 ICP-QMS

2 MC-ICP-MS

Instrumentation


4

High ion transmission = high sensitivity

Can be operated in high resolution mode(s)

Flat-top peaks in low resolution

Instrumental dark current <0.2 cps

Flexible introduction system

Relatively low matrix tolerance

Large and heavy

Expensive

Requires experienced operators

ICP-SectorFieldMS = HighResolution-ICP-MS = Double Focusing ICP-MS


5

Before MS

Sample collection

Homogenization – representative sub-sample, contamination

Digestion – recovery from matrix, (co)precipitation and volatile losses,

contamination

Column separation – purification efficiency, yield, contamination

Evaporation/re-dissolution – recovery, contamination


6

The UltraCLAVE Principle

The patented* Milestone UltraCLAVE

achieves extraordinary performance

capabilities by combining direct

microwave heating in a high pressure

reactor, which acts simultaneously as

microwave cavity and vessel.

The next generation MW system

The Milestone UltraCLAVE


7

What a difference a droplet (10 µl) HF makes…


8

What a difference a droplet (10 µl) of HF makes…

3600 →


9

Sensitivity

Matrix tolerance

Spectral interferences

Instrumental background

Analyte blank

Accurate measurement - factors to consider

Measured signal

Signal from analyte

presented in sample

Unwanted contributions


10

Sensitivity – upper limit

• Analyte – 239

Pu

• Sample uptake – 0.2 ml/min

• Transport efficiency – 100%

• Law of conservation of mass is still valid

Highest possible sensitivity for 1 pg l-1

8400 counts s-1


11

Cell ICP-QMS: 0.1-2

ICP-SFMS, standard set-up: 2

ICP-SFMS, X skimmer, CH4: 5-8

ICP-SFMS, X skimmer, Aridus + N2: 20-30

MC-ICP-MS, Jet interface, APEX: 110-140

’Record’ transport efficiency of ICP-MS is under 2%

Sensitivity in LRM, counts s-1 per 1 pg l-1 238U


12

High efficiency nebulizers – Aridus II and Apex HF

Intensity gain by efficient utilization of sample

solution

’Dry’ plasma – much lower O, H and OH

interferences

Great signal stability for low-matrix solutions

Losses of volatile elements (Hg, Se, As, Os, B)

Low matrix tolerance

Long memory


13

Sensitivity in LRM, counts s-1 per 1 pg l-1


14

BEC, ppq LOD, ppq LOQ, ppq Major interferences

226Ra 0.11 0.18 0.59 WAr, ReArH, PbOH2, BaSr, BaCaCa

230Th 0.09 0.14 0.45 Th, U tails, OsAr, PtO2, HgO2, IrCl, PtCl

232Th 44 11 36 OsAr, HgO2, AuCl, PtCl

234U 0.07 0.14 0.48 ThH2, Th, U tails, PtAr, AuCl, PtCl

235U 0.22 0.53 1.8 U tail, PtAr, HgCl, PtCl, HgO2

236U 0.07 0.17 0.56 UH, U tail, PtAr, HgCl, HgO2

237Np 0.09 0.15 0.51 U tail, UH2, AuAr, HgCl, HgO2

238U 30 7 23 PtAr, HgAr, HgCl, TlCl, PbO2

239Pu 0.03 0.08 0.25 UH, U tail, HgAr, HgCl, PbCl, PbO2

240Pu 0.03 0.06 0.21 UH2, U tail, HgAr, TlCl, PbO2

241Am 0.05 0.06 0.20 U tail, HgAr, HgCl, PbCl, BiO2

242Pu 0.03 0.05 0.16 U tail, HgAr, TlCl, PbCl

243Am 0.06 0.06 0.19 TlAr, PbCl

Summary of BEC, limits and interferences


15

BEC, ppq LOD, ppq LOQ, ppq Major interferences

226Ra 0.11 0.18 0.59 WAr, ReArH, PbOH2, BaSr, BaCaCa

230Th 0.09 0.14 0.45 Th, U tails, OsAr, PtO2, HgO2, IrCl, PtCl

232Th 44 11 36 OsAr, HgO2, AuCl, PtCl

234U 0.07 0.14 0.48 ThH2, Th, U tails, PtAr, AuCl, PtCl

235U 0.22 0.53 1.8 U tail, PtAr, HgCl, PtCl, HgO2

236U 0.07 0.17 0.56 UH, U tail, PtAr, HgCl, HgO2

237Np 0.09 0.15 0.51 U tail, UH2, AuAr, HgCl, HgO2

238U 30 7 23 PtAr, HgAr, HgCl, TlCl, PbO2

239Pu 0.03 0.08 0.25 UH, U tail, HgAr, HgCl, PbCl, PbO2

240Pu 0.03 0.06 0.21 UH2, U tail, HgAr, TlCl, PbO2

241Am 0.05 0.06 0.20 U tail, HgAr, HgCl, PbCl, BiO2

242Pu 0.03 0.05 0.16 U tail, HgAr, TlCl, PbCl

243Am 0.06 0.06 0.19 TlAr, PbCl

Summary of BEC, limits and interferences


16

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

218

220

222

224

226

228

230

232

234

236

238

240

m/z

Inte

nsit

y, co

un

ts s

-1

Tailing


17

Standard Aridus II Aridus II+RPQ*

Th

-2 amu 1.5*10-6 1.2*10-6 0.4*10-6

-1 amu 4*10-6 2*10-6 0.8*10-6

+1 amu 65*10-6 16*10-6 5*10-6

+2 amu 10*10-6 2*10-6 0.7*10-6

U

-2 amu 1.7*10-6 1.4*10-6 0.4*10-6

-1 amu 4*10-6 2*10-6 0.8*10-6

+1 amu 72*10-6 17*10-6 5*10-6

+2 amu 11*10-6 2*10-6 0.8*10-6

Retarding Potential Quadrupole lense adjusted to provide >80% of original sensitivity


18

Matrix separation/preconcentration

20-200 times improvement compared to direct

analysis after dilution


19

Memory effects (self aspiration, Aridus II)


20

Memory effects (self aspiration, Aridus II)

Blanks (1.4 M HO3) 50 ng L-1 239Pu, 242Pu STDs Blanks with HF


21

In tubing – min. length and strong rinse solutions

In spray chamber – low-volume or DIN, matrix optimization

(suppression of volatile species formation)

On cones – use ’Si-trick’

Inside MS – wait…

Memory effects


22

Why Luleå?

October January April


23

Ag

Pt/Au

Sn

Si

Torch and interface may release


24

Personnel issues

Spot the common denominator?

Stibnite

Antimonite

Sb2S3


25

• Al, Cl, Zr, Hf, Si

Aluminium Chlorohydrate, Aluminium

Zirconium Tetrachlorohydrex Gly,

Silica, Silica Dimethyl Silyate, Hf

Deodorants


26

Faster and more convenient way

to handle relatively large sample

volumes (>5 ml)

Contaminates sample with Pt

and Ir at ppt level, Pd and Au at

ppq level because of Pt-Ir valve

spring

’Metall-free’ dispenser


27

Au

0,0

0,2

0,4

0,6

0,8

1,0

1,2

Road Domestic Laboratory 1 Laboratory 2

Co

ncen

trati

on

, µ

g g

-1

Concentrations of ‘rare’ elements are enriched in laboratory dust


28

Dedicated areas for ultra-trace preparations


29

All labware in contact with samples is acid cleaned


30

Applications dictate choice of tube materials


31

ICP-SFMS offers instrumental LODs in sub-ppq range

Ultimate technique for multi-element determination

in variety of matrices

232

Th, 235

U, 238

U can be accurately measured almost

in any matrices

Analysis at endogenous levels of 226

Ra, 230

Th, Pu, Am

will require matrix separation/pre-concentration and

optimized introduction systems

Conclusions


32

Thank you for your attention!


33

206Pb

++

87Rb

16O

+,

87Sr

16O

+, 86

Sr16

OH+

63Cu

40Ar

+, 65

Cu36

Ar+, 67

Zn36

Ar+

23Na

40Ar

40Ar

+,

23Na

40Ar

40Ca

+,

23Na

40Ca

40Ca

+

66Zn

37Cl

+,

68Zn

35Cl

+

32S

34S

37Cl

+, 33S

33S

37Cl

+, 34S

34S

35Cl

+, 34

S34

S34

SH+

96Mo

7Li

+, 97

Mo6Li

+, 40

Ar35

Cl12

C16

O+

Spectral interferences on 103Rh

The majority of spectral interferences can be eliminated using high resolution capabilities of ICP-SFMS


34

Interferences


35

Why Luleå?


36

Determination of TCEs in environmental matrices

Ga, Ge, In, Nb, Ta, Te, Tl Ir, Os, Pd, Pt, Rh

Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Y, Yb

Quantitate recovery at preparation stages

Preventing losses during analysis

Optimization of instrumental conditions (low oxides)

Right resolution settings

Matrix separation if necessary

Analyte specific introduction (Os, Ge)

Documents

Determination of trace and ultra- trace elements by ICP-SFMS · 2018. 1. 15. · 238U 30 7 23 PtAr , HgAr HgCl TlCl, PbO 2 239Pu 0.03 0.08 0.25 UH, U tail , HgAr HgCl PbCl, PbO 2