Weblims     OWA     Home     Contact Us    

Actlabs
Back to Home


144 of 150    Prev    Next     

Ultratrace 3 - INAA + 4-Acid Digestion/ICP-OES/ICP-MS

Ultratrace-3 is a combination of our 1H procedure (INAA and multi-acid digestion ICP) combined with ICP/MS on the same solution we use for ICP/OES. Some elements reported by ICP/MS are duplicated by INAA and indicate the degree of dissolution as certain elements reside in very resistate phases like zircon, monazite, sphene, xenotine, chromite, barite, etc. which can’t be totally dissolved with any acids. To ensure complete dissolution we suggest our Code 4 group packages. The ICP/MS used for this package is a Perkin Elmer-SCIEX ELAN 6000.
 
INAA Portion

A 30 g aliquot, if available, is encapsulated 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 1012 n cm-2s-1. After a 7-day period, to allow Na-24 to decay, the samples are counted on a high purity Ge detector with resolution of better than 1.7 KeV for the 1332 KeV Co-60 photopeak. 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 and is not used for calibration purposes. From 10-30% of the samples are rechecked by re-measurement. For values exceeding the upper limits, assays are recommended.


One standard is run for every 11 samples. One blank is analyzed per work order. Duplicates are analyzed when samples are provided.


4-Acid "Near Total" Digestion - ICP Portion

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 holdingcycles which takes the samples to incipient dryness. After incipient dryness is attained, samples are brought back into solution using aqua regia.


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 5000 ppm should be assayed as high levels may not be solubilized.  Only sulphide sulfur will be solubilized.


The samples are then analyzed using a Varian ICP.  QC for the digestion is 14% for each batch, 5 method reagent blanks, 10 in-house controls, 10 samples duplicates, and 8 certified reference materials.  An additional 13% QC is performed as part of the instrumental analysis to ensure quality in the areas of instrumental drift.


 
4-Acid "Near Total" Digestion – ICP/MS Portion

Additional elements are determined by ICP/MS on the multi-acid digest solution above. The samples are diluted and analyzed on a Perkin Elmer Sciex ELAN 6000, 6100 or 9000 ICP/MS. One blank is run for every 40 samples. In-house control is run every 20 samples. Digested standards are run every 80 samples. After every 15 samples, a digestion duplicate is analyzed. Instrument is recalibrated every 80 samples.


 
Code Ultratrace-3 Elements and Detection Limits (ppm)

Element

Detection Limit

Upper Limit

Reported By

Element

Detection Limit

Upper Limit

Reported By

Ag*

0.05

10,000

INAA,ICP &ICP/MS

Mn

1

100,000

ICP

Al

0.01%

50%

ICP

Mo

0.2

10,000

ICP

As

0.5

10,000

INAA

Na

0.01%

20%

INAA

Au

2 ppb

30,000 ppb

INAA

Nb

0.1

500

ICP/MS

Ba *

1

100,000

INAA & ICP

Nd

0.01

10,000

ICP/MS

Be *

0.1

1,000

ICP & ICP/MS

Ni *

0.5

100,000

INAA, ICP & ICP/MS

Bi *

0.02

10,000

ICP &ICP/MS

P

0.001%

10%

ICP

Br

0.5

5000

INAA

Pb *

0.5

5,000

ICP &ICP/MS

Ca

0.01%

70%

ICP

Pr

0.1

1,000

ICP/MS

Cd *

0.1

2,000

ICP &ICP/MS

Rb *

0.2

5,000

INAA &ICP/MS

Ce

0.1

10,000

ICP/MS

Re

0.001

100

ICP/MS

Co *

1

5,000

INAA & ICP/MS

S+

0.01%

20%

ICP

Cr *

1

10,000

INAA &ICP/MS

Sb

0.1

10,000

INAA

Cs *

0.05

5,000

INAA &ICP/MS

Sc

0.1

1,000

INAA

Cu *

0.2

10,000

ICP &ICP/MS

Se *

0.1

10,000

INAA &ICP/MS

Dy

0.1

5,000

ICP/MS

Sm

0.1

100

ICP/MS

Er

0.1

1,000

ICP/MS

Sn

1

200

ICP/MS

Eu

0.05

1,000

ICP/MS

Sr

0.2

1,000

ICP/MS

Fe

0.01%

70%

INAA

Ta *

0.1

10,000

INAA &ICP/MS

Ga

0.1

500

ICP/MS

Tb

0.1

5,000

ICP/MS

Ge

0.1

500

ICP/MS

Te

0.02

500

ICP/MS

Gd

0.1

500

ICP/MS

Th *

0.1

10,000

INAA &ICP/MS

Hf

0.1

5,000

ICP/MS

Ti

0.01%

10%

ICP

Hg

10 ppb

10,000 ppb

INAA

Tl

0.05

500

ICP/MS

Ho

0.1

1,000

ICP/MS

Tm

0.1

1,000

IPC/MS

Ir

5 ppb

10,000 ppb

INAA

U *

0.1

10,000

INAA & ICP/MS

In

0.1

100

ICP/MS

V

1

10,000

ICP

K

0.01%

10%

ICP

W

1

10,000

ICP

La

0.5

10,000

ICP/MS

Y

0.01

10,000

ICP/MS

Li

0.5

10,000

ICP/MS

Yb

0.1

5,000

ICP/MS

Lu

0.1

100

ICP/MS

Zn *

0.5

100,000

INAA, ICP &ICP/MS

Mg

0.01%

50%

ICP

 

Zr

1

5,000

ICP/MS

 

Notes:    
Extraction of each element by 4-Acid Digestion is dependent on mineralogy.  

Unaltered silicates and resistate minerals may not be dissolved.

*  Element reported by multiple techniques if one or more techniques may not be total.

+ Sulphide sulphur and soluble sulphates are extracted.


Reference
Hoffman, E.L., 1992. Instrumental Neutron Activation in Geoanalysis. Journal of Geochemical Exploration, volume 44, pp. 297-319.

 


Activation Laboratories Ltd. | 41 Bittern Street, Ancaster, Ontario, L9G 4V5, Canada | TF: +1.888.228.5227
Search | Privacy | Contact Us | News RSS | Login