Pushing the Envelope for Beam Sensitive Samples and Trace Element

Sensitivity and Accuracy

John Donovan

(541) 343-3400donovan@probesoftware.com

www.probesoftware.com

Every sample is beam sensitive at a sufficiently high beam current...

•Usually thermally insulating samples (e.g., non conductors…)

•Classical beam sensitive samples (e.g., alkali, hydrous glasses)•Orientation dependent intensity changes over time (e.g., apatites)•Trace element measurements (high beam currents, long counting)

•Use alternating on and off-peak measurements (constant delta)•Extrapolate to zero time intensities•Use a “blank” correction to apply a systematic error offset

SiO2 Glass SiO2 Quartz

Fe K and Si k in VG2 Glass

Alternating On and Off peak Acquisition To Document Sample Stability

15 keV, 100nA, 20um

F Ka in VG2 Glass (1800 secs total count time)

Water By Difference From 100%

•Effects from Water By Difference•Effects from Na, Si, etc “migration”

•Measure all Cations•Calculate Oxygen (assume stoichiometry for Fe, etc.)

•Subtract from 100 to Obtain H2O

Matrix Effects:

Time Dependent Intensity (TDI) Corrections

Intensity Changes over Time•Na, K, Si, Al, etc.•Improved Accuracy of Measured Elements

Correcting for Intensity Loss (and Gain)Results in Oxide Weight Percents

ELEM: Na2O SiO2 Al2O3 MgO TiO2 MnO P2O5 Cl FeO K2O CaO O H2O SUM 169 1.140 72.895 12.112 .065 .080 .052 .007 .174 .502 4.323 .823 -.039 7.867 100.000 170 1.267 72.815 11.824 .069 .143 .032 -.009 .172 .512 4.536 .869 -.039 7.809 100.000

AVER: 1.204 72.855 11.968 .067 .112 .042 -.001 .173 .507 4.429 .846 -.039 7.838 100.000SDEV: .090 .056 .204 .003 .045 .014 .011 .001 .007 .150 .032 .000 .041SERR: .064 .040 .144 .002 .032 .010 .008 .001 .005 .106 .023 .000 .029%RSD: 7.5 .1 1.7 4.2 40.4 33.9 -806.3 .4 1.3 3.4 3.8 -.4 .5VOL%: 96.461 -2.091 -1.673 ---- ---- ---- ---- ---- 1.218 60.289 ---- ---- ----DEV%: 18.1 .6 .8 ---- ---- ---- ---- ---- 5.0 6.1 ---- ---- ----VOLF: LINEAR LINEAR LINEAR ---- ---- ---- ---- ---- LINEAR LINEAR ---- ---- ----

But Not Always What You Expect!

Hyper-exponential Loss

Results in Oxide Weight PercentsELEM: Na2O SiO2 Al2O3 MgO TiO2 MnO P2O5 Cl FeO K2O CaO O H2O SUM 169 1.790 72.897 12.121 .065 .080 .052 .007 .173 .501 4.318 .823 -.039 7.213 100.000 170 1.969 72.817 11.833 .069 .143 .032 -.009 .172 .511 4.530 .868 -.039 7.103 100.000

AVER: 1.879 72.857 11.977 .067 .111 .042 -.001 .173 .506 4.424 .845 -.039 7.158 100.000SDEV: .127 .056 .203 .003 .045 .014 .011 .001 .007 .150 .032 .000 .078SERR: .090 .040 .144 .002 .032 .010 .008 .001 .005 .106 .023 .000 .055%RSD: 6.7 .1 1.7 4.2 40.4 33.9 -806.4 .4 1.3 3.4 3.8 -.4 1.1

VOL%: 201.072 -2.091 -1.673 ---- ---- ---- ---- ---- 1.218 60.289 ---- ---- ----DEV%: 4.0 .6 .8 ---- ---- ---- ---- ---- 5.0 6.1 ---- ---- ----VOLF: QUADRA LINEAR LINEAR ---- ---- ---- ---- ---- LINEAR LINEAR ---- ---- ----

Can We Test This Extrapolation?

Results in Oxide Weight Percents (20 nA)ELEM: Na2O SiO2 Al2O3 MgO TiO2 MnO P2O5 Cl FeO K2O CaO O H2O SUM AVER: 2.369 68.336 15.543 1.095 .444 .041 .069 .058 2.083 4.588 2.037 -.013 .000 96.651VOL%: 204.518 -1.701 -1.373 ---- ---- ---- ---- ---- -5.860 59.030 ---- ---- ----DEV%: 5.2 .6 1.0 ---- ---- ---- ---- ---- 4.0 5.9 ---- ---- ----

Results in Oxide Weight Percents (15 nA)ELEM: Na2O SiO2 Al2O3 MgO TiO2 MnO P2O5 Cl FeO K2O CaO O H2O SUM AVER: 2.313 67.383 15.537 1.263 .468 .018 .103 .068 2.449 4.608 2.137 -.015 .000 96.332VOL%: 161.641 -1.461 -1.222 ---- ---- ---- ---- ---- -.434 49.134 ---- ---- ----DEV%: 4.5 .4 .7 ---- ---- ---- ---- ---- 2.8 4.5 ---- ---- ----

Results in Oxide Weight Percents (10 nA)ELEM: Na2O SiO2 Al2O3 MgO TiO2 MnO P2O5 Cl FeO K2O CaO O H2O SUM AVER: 2.443 66.558 15.314 1.129 .533 .031 .109 .065 2.401 4.822 2.058 -.015 .000 95.448VOL%: 134.049 -1.407 -1.495 ---- ---- ---- ---- ---- -.343 36.614 ---- ---- ----DEV%: 3.2 .6 .9 ---- ---- ---- ---- ---- 4.5 3.2 ---- ---- ----

Results in Oxide Weight Percents (5 nA)ELEM: Na2O SiO2 Al2O3 MgO TiO2 MnO P2O5 Cl FeO K2O CaO O H2O SUM AVER: 2.289 65.294 14.953 1.176 .416 .055 .093 .059 2.263 5.022 2.094 -.013 .000 93.699VOL%: 68.999 -.940 -.311 ---- ---- ---- ---- ---- -3.779 18.498 ---- ---- ----DEV%: 3.2 .8 1.4 ---- ---- ---- ---- ---- 4.9 3.0 ---- ---- ----

Matrix Effects from “missing” elements

Results in Oxide Weight Percents

ELEM: CaO K2O FeO SiO2 MgO Na2O Al2O3 TiO2 P2O5 O H2O SUM 58 .411 4.900 .537 74.603 .036 2.644 11.975 .073 .000 .000 .000 95.180 59 .437 4.624 .612 75.386 .033 1.841 12.024 .113 .000 .000 .000 95.070 60 .423 4.998 .526 74.715 .023 2.765 12.113 .065 .000 .000 .000 95.628 61 .423 4.853 .637 75.000 .047 2.137 12.089 .055 .000 .000 .000 95.240 62 .435 4.847 .677 74.613 .048 2.561 12.089 .036 .011 .000 .000 95.317

AVER: .426 4.844 .598 74.863 .037 2.390 12.058 .068 .002 .000 .000 95.287SDEV: .011 .137 .065 .333 .010 .387 .057 .028 .005 .000 .000%RSD: 2.5 2.8 10.8 .4 27.9 16.2 .5 41.5 223.6 418.3 .0

ZCOR: 1.1202 1.1536 1.1987 1.2061 1.4303 1.8227 1.2568 1.1983 1.4641 .0000 .0000KRAW: .0161 .3080 .0057 1.0344 .0003 .1323 .7242 .0006 -.0004 .0000 .0000PKBG: 4.96 59.36 4.84 370.59 1.42 30.93 77.40 1.46 .87 .00 .00

No Volatile Correction, No Water By Difference

Excel Spreadsheet Subtraction Gives ~ 4.7% H2O

Volatile Correction Matrix Effects

Results in Oxide Weight Percents

ELEM: CaO K2O FeO SiO2 MgO Na2O Al2O3 TiO2 P2O5 O H2O SUM 58 .411 4.867 .537 74.378 .037 3.626 12.035 .030 .000 .000 .000 95.921 59 .437 4.740 .612 75.016 .034 2.426 12.063 .194 .000 .000 .000 95.521 60 .423 4.933 .526 74.057 .024 3.805 12.178 .076 .000 .000 .000 96.022 61 .423 5.220 .636 74.552 .048 3.025 12.147 .077 .000 .000 .000 96.128 62 .435 4.715 .677 74.794 .049 3.503 12.146 .048 .011 .000 .000 96.378

AVER: .426 4.895 .598 74.559 .038 3.277 12.114 .085 .002 .000 .000 95.994SDEV: .011 .203 .065 .370 .010 .557 .062 .064 .005 .000 .000%RSD: 2.5 4.1 10.8 .5 27.3 17.0 .5 75.6 223.6 .0 .0

ZCOR: 1.1198 1.1530 1.1983 1.2092 1.4391 1.8180 1.2625 1.1979 1.4627 .0000 .0000KRAW: .0161 .3114 .0057 1.0276 .0003 .1819 .7242 .0008 -.0004 .0000 .0000PKBG: 4.97 60.00 4.84 369.28 1.43 42.09 77.77 1.58 .87 .00 .00VOL%: .000 1.135 .000 -.658 .000 36.111 .000 20.283 .000 .000 .000DEV%: .0 .2 .0 .0 .0 .4 .0 20.3 .0 .0 .0

With Volatile Correction, No Water By Difference

Na, Si, K Intensity Over Time Iteration Gives ~ 4% H2O

Water By Difference Matrix Effects

Results in Oxide Weight Percents

ELEM: CaO K2O FeO SiO2 MgO Na2O Al2O3 TiO2 P2O5 O H2O SUM 58 .414 4.885 .542 74.776 .039 3.668 12.139 .030 .000 .000 3.506 100.000 59 .441 4.759 .618 75.464 .036 2.457 12.181 .195 .000 .000 3.849 100.000 60 .426 4.951 .531 74.441 .026 3.848 12.281 .076 .000 .000 3.420 100.000 61 .426 5.239 .641 74.934 .050 3.058 12.249 .077 .000 .000 3.327 100.000 62 .438 4.730 .682 75.149 .051 3.539 12.240 .048 .011 .000 3.112 100.000

AVER: .429 4.913 .603 74.953 .041 3.314 12.218 .085 .002 .000 3.443 100.000SDEV: .011 .203 .065 .385 .010 .562 .057 .065 .005 .000 .270%RSD: 2.5 4.1 10.8 .5 25.7 16.9 .5 75.6 223.6 -104.6 7.9

ZCOR: 1.1241 1.1571 1.2053 1.2156 1.4515 1.8372 1.2731 1.2037 1.4591 .0000 .0000KRAW: .0161 .3114 .0057 1.0276 .0004 .1821 .7244 .0008 -.0004 .0000 .0000PKBG: 5.03 60.00 4.89 372.20 1.46 43.35 78.99 1.58 .87 .00 .00VOL%: .000 1.135 .000 -.658 .000 36.111 .000 20.283 .000 .000 .000DEV%: .0 .2 .0 .0 .0 .4 .0 20.3 .0 .0 .0

With Volatile Correction, Water By Difference

Both Na, Si, K Change and Water By Difference Gives 3.4% H2O

Water By Difference vs. FTIR

Comparison of melt inclusion water contents measured by FTIR in sub-micron melt inclusion water contents estimated as the difference between 100% and microprobe analysis totals or “water by difference” (WBD).

Solid diagonal line indicates 1:1 correspondence, dashed line is a linear regression fixed at the origin. Gray symbols show WBD water content before matrix correction of the analysis and black symbols show matrix-corrected WBD estimates.

From Roman, 2003

29000 30000 31000 32000 33000 34000Spectrom eter 2 LPET position (s in theta * 10 5)

2.2

2.4

2.6

2.8

3

3.2

Ti K

c

ps/

nA

0

400

800

1200

1600

2000

Ti K

c

ps/n

A

20keV, 100nA, 20um beam

S iO 2 220 sec/po int

T iO 2 40 sec/po int

Continuum Artifacts

The “Blank” Correction

Spectrometer-Crystal 1-PET 2-LPET 3-LPET 4-PET 4-PET

Set 1, Ti Concentration Average (without blank correction) -0.8 -12.3 -29.5 4.7 -3.4

Set 2, Ti Concentration Average (without blank correction) 1.2 -11.4 -29.7 7.3 -1.4

Set 1, Measured Deviation (1 ) 5.8 2.3 1.2 6.5 2.3

Set 2, Measured Deviation (1 ) 3.9 2.7 3.5 5.2 1.4

Set 1, Ti Concentration Average (with blank correction) -0.6 0.5 1.6 -1.2 -0.6

Set 2, Ti Concentration Average (with blank correction) 3.5 2.3 1.2 4.0 3.4

Accuracy at the 400 PPM Level?

0 400 800 1200 1600

0.02

0.04

0.06

0.08

0 400 800 1200 1600

R elative D istance (um )

0.02

0.04

0.06

0.08

Ti W

eig

ht %

R efug io -1 7 Tra ve rse 2T i Ka Spec 2 (LPET)

T i Ka Spec 4 (PET)

0 400 800 1200 1600

0.02

0.04

0.06

0.08

0 400 800 1200 1600

R ela tive D istance (um )

0.02

0.04

0.06

0.08

Ti W

eig

ht %

Uncorrected for B lank Iteration

Corrected for B lank Iteration

unk

std

std

levelmeasstdunkcorr ZAF

ZAF

C

CCIII

][

][*

)(*

Note: Blank level (Clevel) can be non-zero

1 10 100 1000 10000

O n-Peak In tegration T im e (sec)

0.0000

0.0020

0.0040

0.0060

0.0080

0.0100

0.0120

0.0140

0.0160

0.0180

3 S

igm

a R

epor

ted

Det

ectio

n (w

t. %

)

Ti in S iO2 , 2 0 ke V , 2 0 0 n A , 2 0 u mC a lc. fro m L o ve a n d Sco tt (1 9 8 3 )

Spectrom eter 1 (P ET)

Spectrom eter 2 (LP ET)

Spectrom eter 3 (LP ET)

Spectrom eter 4 (P ET)

Spectrom eter 5 (P ET)

Aggregate In tensity O ption

PET

LPET

5 Spectrometers

1 10 100 1000 10000

O n-Peak In tegration T im e (sec)

1E-005

0.0001

0.001

0.01

0.1

Det

ectio

n Li

mit

(t-t

ests

) (w

t. %

)

Ti in S iO2 , 2 0 ke V , 2 0 0 n A , 2 0 u mC a lc. fro m Go ld ste in , e t a l., (1 9 9 2 )

Spectrom eter 1 (99% C I)

Spectrom eter 1 (95% C I)

Spectrom eter 1 (90% C I)

Spectrom eter 1 (80% C I)

Spectrom eter 1 (60% C I)

Aggregate In tensity (60% C I)

(normal PET crystal)

5 Spectrometers1 ppm

Water By Measured Excess Oxygen

(Nash, 1992)

H20 (FTIR) Na2O Content(wt%)

K2O Content(wt%)

SiO2 Content(wt%)

NSL 0.01 (0.13) 5.5 4.4 74.4N1 1.16 (1.16) 5.3 4.4 72.3N3 3.28 (3.30) 5.4 4.3 72.1N3.35 3.56 (3.51) 5.1 4.3 70.4N4b 4.11 (4.11) 5.1 4.2 71.3N5 4.90 (5.06) 4.5 4.2 70.5

Wither’s Synthetic Rhyolite Glasses

•Measure All Cations•Measure Oxygen (easier said than done)•Calculate Stoichiometric Oxygen From Cations•Subtract Stoichiometric Oxygen From Measured Oxygen•Calculate Water By Stoichiometry To Hydrogen (OH, H2O)

Where do we stand today if we do not use an oxygen standard similar to our unknowns?

(Combined TDI and “Blank” Corrections)

Accuracy Issues for Oxygen Analysis•Sample/Standard Roughness and Sample/Standard Carbon Coat Thickness

- Use 0.05 um final polish- Coat standards and unknowns simultaneously

•Sample Conditions- Lower voltages (for oxygen), defocus beam (reduce damage)

•PHA adjustments- Na Ka II on O ka (use differential mode)

•Missing elements and cation valences- Li, Be, B, C (and Ba, Sr, etc)- Fe2+, Fe3+

•Matrix Corrections- Take your pick!

•Mass Absorption Coefficients and Area Peak Factors (APFs)- Use modern MAC database (FFAST), empirical MACs

Wither’s Glass Analyses (using MgO std)

•Armstrong phi-rho-z, FFAST MACS, no APFs, no volatile corr.

3.9 wt% Na2O 4.5 wt % Na2O

Na2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO H2O TotalNSL 4.176 4.454 0.225 -0.006 0.088 0.214 4.082 0.076 0.175 74.266 10.345 0.003 -1.078 97.02N1 3.668 4.407 0.218 0.018 0.075 0.255 4.148 0.072 0.195 72.166 10.36 0.007 0.61 96.198N3 2.945 4.283 0.221 0.017 0.075 0.209 4.053 0.077 0.193 72.048 10.131 0.009 2.84 97.102N3.35 2.874 4.291 0.204 -0.003 0.079 0.22 4.219 0.101 0.193 70.421 10.146 0.005 3.68 96.43N4b 2.649 4.19 0.226 0.008 0.072 0.216 3.935 0.091 0.202 71.46 10.129 0.009 4.186 97.372N5 2.175 4.195 0.217 -0.003 0.081 0.196 4.052 0.081 0.192 70.704 10.071 0.007 5.556 97.525

Hyper-exponential Loss

Two exponential processes with different decay constants overlapping in time(?)

Add Volatile Corrections•Intensity changes for Na, K, Si and O (ignoring Al!)Si Ka, -0.73% relative O Ka, -2.9% relative O Ka, -3.7% relative

Linear Extrapolation Quadratic ExtrapolationNa2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO H2O Total

NSL 5.442 4.412 0.225 -0.006 0.088 0.214 4.077 0.076 0.175 74.254 10.394 0.004 -1.536 97.819N1 5.257 4.446 0.218 0.018 0.074 0.254 4.14 0.072 0.195 72.102 10.414 0.007 -0.358 96.838N3 5.422 4.27 0.221 0.017 0.074 0.208 4.038 0.077 0.192 71.936 10.206 0.01 1.055 97.726N3.35 5.061 4.289 0.204 -0.003 0.077 0.219 4.203 0.101 0.192 70.261 10.21 0.006 1.921 96.741N4b 5.131 4.211 0.225 0.008 0.071 0.215 3.92 0.091 0.201 71.153 10.204 0.01 2.346 97.786N5 4.529 4.198 0.217 -0.003 0.079 0.195 4.036 0.081 0.191 70.404 10.138 0.008 3.607 97.682

Add APFs and Empirical MACsFFAST vs. Empirical MACs

Emitter Absorber FFAST-2005"o" "ka" "f" 1534 1850 "Love et al. (1974)""o" "ka" "na" 3184 3630 "Love et al. (1974)""o" "ka" "mg" 4387 5170 "Bastin (1992)""o" "ka" "al" 5679 6720 "Bastin (1992)""o" "ka" "si" 7546 8790 "Bastin (1992)""o" "ka" "cl" 13318 14300 "Love et al. (1974)""o" "ka" "k" 18723 20500 "Love et al. (1974)""o" "ka" "ca" 21866 24600 "Love et al. (1974)""o" "ka" "ti" 22425 19900 "Bastin (1992)""o" "ka" "mn" 3223 3470 "Bastin (1992)""o" "ka" "fe" 3628 4000 "Bastin (1992)"

Area Peak Factors (APFs)Emitter Absorber"o" "ka" "mg" 1 "MgO/Fe2O3/WSi/59.8""o" "ka" "al" 1.0213 "Al2O3/Fe2O3/WSi/59.8, Bastin""o" "ka" "si" 1.0444 "SiO2/Fe2O3/WSi/59.8, Bastin""o" "ka" "ca" 0.97 "----/Fe2O3/WSi/59.8""o" "ka" "ti" 0.9796 "TiO2/Fe2O3/WSi/59.8""o" "ka" "fe" 0.9962 "Fe3O4/Fe2O3/WSi/59.8"

Selected Samples

WS

i60

cps

(20

sec

per p

oint

)

O (1) Spectrometer

0.0

0.2

0.4

0.6

0.8

1.0

33764 34853 35942 37031 38120 39209 40298 41387 42476 43565 44654

5439. -5308.

C:\UserData\Donovan\APF Tests\MgO-Al2O3-SiO2.MDB, 10/18/2000 5:13:10 AM

MgOAl2O3SiO2

IS

PS

PU

IU

I

I

I

IAPF

nj

j

ji

jicomp APFCAPF

1][][

Na2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO H2O TotalNSL 5.485 4.425 0.225 -0.006 0.089 0.214 4.098 0.077 0.176 74.554 10.457 0.005 1.193 100.991N1 5.297 4.459 0.218 0.018 0.075 0.255 4.161 0.073 0.196 72.383 10.475 0.008 2.325 99.942N3 5.464 4.283 0.221 0.017 0.075 0.209 4.058 0.077 0.193 72.215 10.266 0.011 3.791 100.88N3.35 5.099 4.301 0.204 -0.003 0.078 0.22 4.224 0.102 0.193 70.527 10.268 0.007 4.624 99.843N4b 5.17 4.223 0.226 0.008 0.071 0.216 3.939 0.091 0.202 71.425 10.263 0.011 5.109 100.954N5 4.562 4.21 0.217 -0.003 0.08 0.196 4.056 0.081 0.192 70.672 10.196 0.009 6.392 100.861

“Blank” Correction…

29000 30000 31000 32000 33000 34000Sp e ctro m e te r 2 L PE T p ositio n (s in th e ta )

220

240

260

280

300

320

cps/

30

nA

0

40000

80000

120000

160000

200000

cps/

30

nA

2 0 ke V , 1 0 0 n A , 2 0 u m b e a m

S iO 2 220 sec/po int

T iO 2 40 sec/po in t

Continuum artifacts

unk

std

std

levelmeasstdunkcorr ZAF

ZAF

C

CCIII

][

][*

)(*

Accuracy Calibration

ELEM: Na2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO O SUM 598 .034 .016 -.018 .024 .003 .000 14.583 .154 15.353 53.843 .034 14.345 1.687 100.057 599 -.013 .002 .013 .018 .017 -.016 14.396 .130 15.178 54.277 .039 14.302 2.224 100.566 600 .030 -.002 -.039 .016 -.022 -.102 14.545 .131 15.036 53.729 .031 14.376 1.662 99.390 601 .009 .017 .013 -.050 -.015 .027 14.712 .131 15.081 53.783 .048 14.389 1.731 99.875 602 -.006 .016 -.042 -.002 -.030 -.054 14.381 .085 15.115 54.022 .035 14.455 1.804 99.780 603 .092 .033 .031 -.033 .017 .059 14.553 .094 15.195 54.171 .039 14.430 1.413 100.094 604 -.003 .006 -.003 -.012 .017 .016 14.449 .093 15.546 54.148 .033 14.339 1.989 100.618 605 .075 -.003 -.010 .006 .022 .000 14.431 .160 15.224 53.721 .025 14.411 1.611 99.672 606 -.020 -.001 .023 .027 .011 .027 14.461 .162 15.238 53.308 .028 14.350 1.796 99.409 607 -.005 .016 .018 .000 -.011 -.011 14.418 .124 15.514 53.968 .036 14.390 1.657 100.114 608 -.003 .002 .008 -.073 .016 -.005 14.468 .134 15.263 53.684 .036 14.515 2.174 100.217 609 .023 -.008 -.005 .016 -.008 -.075 14.445 .111 15.083 54.327 .047 14.337 2.024 100.318

AVER: .018 .008 -.001 -.005 .001 -.011 14.487 .126 15.236 53.915 .036 14.387 1.814 100.009SDEV: .035 .012 .023 .031 .018 .046 .095 .026 .164 .294 .007 .059 .242SERR: .010 .003 .007 .009 .005 .013 .027 .007 .047 .085 .002 .017 .070%RSD: 197.6 152.8 -2691.0 -583.6 1204.5 -408.2 .7 20.6 1.1 .5 19.0 .4 13.3

NBS K-411 Mineral Glass, (same conditions as unknown)

C.M. Taylor: FeO 4.39, Fe2O3 11.23Total as FeO 14.49, Excess O 1.12

Wither’s Glasses without “Blank” Correction

Wither’s Glasses with “Blank” CorrectionNa2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO H2O Total H2O (FTIR)

NSL 5.469 4.421 0.225 -0.006 0.088 0.214 4.091 0.077 0.175 74.448 10.435 0.004 0.202 99.844 0.13N1 5.283 4.454 0.218 0.018 0.074 0.255 4.153 0.072 0.195 72.281 10.453 0.008 1.339 98.803 1.16N3 5.449 4.278 0.221 0.017 0.074 0.209 4.051 0.077 0.193 72.117 10.245 0.011 2.803 99.744 3.30N3.35 5.085 4.296 0.204 -0.003 0.078 0.219 4.216 0.101 0.193 70.432 10.247 0.006 3.634 98.71 3.51N4b 5.156 4.219 0.225 0.008 0.071 0.216 3.933 0.091 0.202 71.33 10.243 0.01 4.119 99.823 4.11N5 4.551 4.206 0.217 -0.003 0.08 0.196 4.049 0.081 0.192 70.579 10.176 0.008 5.403 99.735 5.06

Na2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO H2O TotalNSL 5.485 4.425 0.225 -0.006 0.089 0.214 4.098 0.077 0.176 74.554 10.457 0.005 1.193 100.991N1 5.297 4.459 0.218 0.018 0.075 0.255 4.161 0.073 0.196 72.383 10.475 0.008 2.325 99.942N3 5.464 4.283 0.221 0.017 0.075 0.209 4.058 0.077 0.193 72.215 10.266 0.011 3.791 100.88N3.35 5.099 4.301 0.204 -0.003 0.078 0.22 4.224 0.102 0.193 70.527 10.268 0.007 4.624 99.843N4b 5.17 4.223 0.226 0.008 0.071 0.216 3.939 0.091 0.202 71.425 10.263 0.011 5.109 100.954N5 4.562 4.21 0.217 -0.003 0.08 0.196 4.056 0.081 0.192 70.672 10.196 0.009 6.392 100.861

unk

std

std

levelmeasstdunkcorr ZAF

ZAF

C

CCIII

][

][*

)(*

43.55844.8064

Accuracy of Oxygen Using Glass Standards

Na2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO O TotalAverage: 0.024 0.003 -0.001 -0.016 0.001 0.008 14.134 0.101 15.121 54.232 0.032 14.439 1.559 99.639Std Dev: 0.017 0.006 0.021 0.041 0.064 0.047 0.208 0.035 0.201 0.128 0.007 0.033 0.218 0.289

Blank: NBS, K-411, no correctionsNa2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO O Total

Average: 0.021 0.003 -0.001 -0.016 0.001 0.008 14.194 0.101 15.115 54.191 0.031 14.409 -0.328 97.729Std Dev: 0.008 0.005 0.021 0.041 0.063 0.047 0.097 0.035 0.202 0.063 0.007 0.038 0.104 0.171

NBS, K-411, with all corrections (excess oxygen should be 1.12 wt%)

Na2O K2O Cl BaO F TiO2 FeO MnO CaO SiO2 Al2O3 MgO O TotalAverage: 0.05 -0.003 0.008 -0.038 0.011 -0.029 9.668 0.093 14.997 45.598 9.288 19.05 1.202 99.895Std Dev: 0.033 0.01 0.02 0.042 0.046 0.03 0.254 0.039 0.343 0.206 0.045 0.071 0.251 0.531

NBS, K-412, with all corrections (excess oxygen should be 0.82 wt%)

Suggestions for Improved Beam Sensitive Sample Accuracy

•Standards (correct for TDI effects here too!)

•Matrix effects of H2O by difference (iterated re-calculation)

•Acquisition parameters (keV, beam focus, current: linear regime)

•MAN backgrounds for speed (minimize damage)

•Intensity changes over time (“volatile” or TDI corrections)

•Oxygen analysis accuracy issues (sample prep, TDI corrections, MACs, APFs, “blank” accuracy correction)

When Analyzing Water by Measuring Excess Oxygen:

Julien Allaz, University of Massachusetts, Tomorrow at 5:30 PM

"Optimizing Background Measurement Accuracy Using Multi-Point Background Positions"