4Litho - Lithium Metaborate/Tetraborate Fusion - ICP and ICP/MS
A combination of packages Code 4B (lithium metaborate/tetraborate fusion ICP whole rock) and Code 4B2 (trace element ICP/MS)
Fused sample is diluted and analyzed by Perkin Elmer Sciex ELAN 6000, 6100 or 9000 ICP/MS. Three blanks and five controls (three before sample group and two after) are analyzed per group of samples. Duplicates are fused and analyzed every 15 samples. Instrument is recalibrated every 40 samples.
For accurate levels of base metals (Cu, Pb, Zn and Ni) option 4B1 (see below) is recommended. Option 4B-INAA (see below) is recommended for As, Bs, high W >100 ppm and Cr > 1,000 ppm. Code 5D is recommended for Sn >50 ppm. Mineralized samples should have the “Quant” option (see below) selected or request assays for values which exceed the range of option 4B1.
Fusion ICP
|
Oxide
|
Detection
Limit (%)
|
|
SiO
2
|
0.01
|
|
Al
2
O
3
|
0.01
|
|
Fe
2
O
3
|
0.01
|
|
MgO
|
0.01
|
|
MnO
|
0.001
|
|
CaO
|
0.01
|
|
TiO
2
|
0.001
|
|
Na
2
O
|
0.01
|
|
K
2
O
|
0.01
|
|
P
2
O
5
|
0.01
|
|
Loss on Ignition
|
0.01
|
Trace Elements and Detection Limits (ppm)
|
Element
|
Detection Limit
|
Upper Limit
|
Reported By
|
|
Element
|
Detection Limit
|
Upper Limit
|
Reported By
|
|
Ag
|
0.5
|
100
|
ICP/MS
|
|
Nd
|
0.1
|
2,000
|
ICP/MS
|
|
As
|
5
|
2,000
|
ICP/MS
|
|
Ni
|
20
|
10,000
|
ICP/MS
|
|
Ba
|
3
|
500,000
|
ICP
|
|
Pb
|
5
|
10,000
|
ICP/MS
|
|
Be
|
1
|
-
|
ICP
|
|
Pr
|
0.05
|
1,000
|
ICP/MS
|
|
Bi
|
0.4
|
2,000
|
ICP/MS
|
|
Rb
|
2
|
1,000
|
ICP/MS
|
|
Ce
|
0.1
|
3,000
|
ICP/MS
|
|
Sb
|
0.5
|
200
|
ICP/MS
|
|
Co
|
1
|
1,000
|
ICP/MS
|
|
Sc
|
1
|
-
|
ICP
|
|
Cr
|
20
|
10,000
|
ICP/MS
|
|
Sm
|
0.1
|
1,000
|
ICP/MS
|
|
Cs
|
0.5
|
1,000
|
ICP/MS
|
|
Sn
|
1
|
1,000
|
ICP/MS
|
|
Cu
|
10
|
10,000
|
ICP/MS
|
|
Sr
|
2
|
10,000
|
ICP
|
|
Dy
|
0.1
|
1,000
|
ICP/MS
|
|
Ta
|
0.1
|
500
|
ICP/MS
|
|
Er
|
0.1
|
1,000
|
ICP/MS
|
|
Tb
|
0.1
|
1,000
|
ICP/MS
|
|
Eu
|
0.05
|
1,000
|
ICP/MS
|
|
Th
|
0.1
|
2,000
|
ICP/MS
|
|
Ga
|
1
|
500
|
ICP/MS
|
|
Tl
|
0.1
|
1,000
|
ICP/MS
|
|
Gd
|
0.1
|
1,000
|
ICP/MS
|
|
Tm
|
0.05
|
1,000
|
ICP/MS
|
|
Ge
|
1
|
500
|
ICP/MS
|
|
U
|
0.1
|
1,000
|
ICP/MS
|
|
Hf
|
0.2
|
1,000
|
ICP/MS
|
|
V
|
5
|
10,000
|
ICP
|
|
Ho
|
0.1
|
1,000
|
ICP/MS
|
|
W
|
1
|
5,000
|
ICP/MS
|
|
In
|
0.2
|
200
|
ICP/MS
|
|
Y
|
2
|
10,000
|
ICP
|
|
La
|
0.1
|
2,000
|
ICP/MS
|
|
Yb
|
0.1
|
1,000
|
ICP/MS
|
|
Lu
|
0.04
|
1,000
|
ICP/MS
|
|
Zn
|
30
|
10,000
|
ICP/MS
|
|
Mo
|
2
|
100
|
ICP/MS
|
|
Zr
|
4
|
10,000
|
ICP
|
|
Nb
|
1
|
1,000
|
ICP/MS
|
|
|
|
|
|
Code 4Litho - Options
4LithoQuant
A 1 g sample is digested with aqua regia and diluted to 250 ml volumetrically. Appropriate international reference materials for the metals of interest are digested at the same time. The samples and standards are analyzed on a Thermo Jarrell Ash ENVIRO II simultaneous and sequential ICP , Varian Vista 735 ICP or Thermo 6500 ICP.
4B1
A 0.25 g sample is digested with four acids beginning with hydrofluoric, followed by a mixture of nitric and perchloric acids, heated using precise programmer controlled heating in several ramping and holding cycles which takes the samples to dryness. After dryness is attained, samples are brought back into solution using hydrochloric acid. With this digestion certain phases may be only partially solubilized. These phases include zircon, monazite, sphene, gahnite, chromite, cassiterite, rutile and barite. Ag greater than 100 ppm and Pb greater than 5,000 ppm should be assayed as high levels may not be solubilized. Only sulphide sulfur will be solubilized.
An in-lab standard (traceable to certified reference materials) or certified reference materials are used for quality control.
Samples are analyzed using a Varian Vista 735 ICP.
Option 4B1
Elements and Detection Limits (ppm)
|
Element
|
Detection Limit
|
Upper Limit
|
|
Ag
|
0.5
|
50
|
|
Cd
|
0.5
|
5,000
|
|
Cu
|
1
|
10,000
|
|
Ni
|
1
|
10,000
|
|
S
|
0.001%
|
20%
|
|
Zn
|
1
|
10,000
|
4B-INAA
An approximately 30 g aliquot if available is encapsulated and weighed in a polyethylene vial and irradiated with flux wires and an internal standard (1 for 11 samples) at a thermal neutron flux of 7 x 10
12
n cm
-2
s
-1
. After a seven day decay to allow Na-24 to decay the samples are counted on a high purity Ge detector with a resolution of better than 1.7 KeV for the 1332 KeV Co-60. Using the flux wires the decay corrected activities are compared to a calibration developed from multiple certified international reference materials. The standard present is only a check on accuracy of the analysis and is not used for calibration purposes. From 10-30% of samples are rechecked by re-measurement.
Further details are available on isotopes and gamma-ray energies used in Hoffman, E.L., 1992. Instrumental Neutron Activation in Geoanalysis. Journal of Geochemical Exploration, volume 44, pp. 297-319.
Option 4B-INAA
Elements and Detection Limits (ppm)
|
Element
|
Detection Limit
|
Upper Limit
|
|
As
|
0.5
|
-
|
|
Au
|
2 ppb
|
30,000 ppb
|
|
Br
|
0.5
|
-
|
|
Cr
|
5
|
100,000
|
|
Ir
|
5 ppb
|
-
|
|
Sb
|
0.2
|
10,000
|
|
Sc
|
0.1
|
-
|
|
Se
|
3
|
-
|
|