MULTI-METHOD ANALYSIS

Mineral Testing Services at Actlabs combines Aqua Regia or 4-Acid Digestion analysis with INAA

4-Acid “Near Total” Digestion with Total Determinations of Resistive Elements by INAA

A 30g sample is analyzed by INAA and with a four acid digestion followed by ICP analysis.

INAA

INAA (Instrumental Neutron Activation Analysis) is an analytical technique dependent on measuring gamma radiation induced in the sample by irradiation with neutrons. The primary source of neutrons for irradiation is usually a nuclear reactor. Each activated element emits a “fingerprint” of gamma radiation which can be measured and quantified. Routine multi-element analyses by INAA are performed on practically any material from the smallest sample which can be weighed accurately to very large samples.

A 30 g aliquot, if available, is encapsulated in a polyethylene vial and irradiated along with flux wires at a thermal neutron flux of 7 x 10 12 ncm-2 s-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 and control standards, the decay-corrected activities are compared to a calibration developed from multiple certified international reference materials. 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 sample material is available.

“Near Total” Digestion – ICP Portion

A 0.25g sample is digested with four acids beginning with hydrofluoric, followed by a mixture of nitric and perchloric acids. This is then heated using precise programmer controlled heating in several ramping and holding cycles 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 an Agilent 735 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.

Elements and Detection Limits (ppm)

Element Detection LimitUpper LimitReported By
Ag  *0.310,000ICP&INAA
Al 0.01%50%ICP
As0.510,000INAA
Au2 ppb30,000 ppbINAA
Ba50500,000INAA
Be110,000ICP
Bi210,000ICP
Br0.55000INAA
Ca0.01%70%ICP
Cd0.32,000ICP
Ce 310,000INAA
Co15,000INAA
Cr 2100,000INAA
Cs110,000INAA
Cu110,000ICP
Eu 0.210,000INAA
Fe 0.01%70%INAA
Hf 15000INAA
Hg110,000INAA
Ir5 ppb10,000 ppbINAA
K0.01%10%ICP
La0.510,000INAA
Li110,000ICP
Lu 0.0510,000INAA
Mg0.01%50%ICP
Element Detection LimitUpper LimitReported By
Mn1100,000ICP
Mo  *110,000ICP
Na0.01%50%INAA
Nd 510,000INAA
Ni  *1100,000ICP&INAA
P0.001%10%ICP
Pb35,000ICP
Rb1510,000INAA
S+0.01%20%ICP
Sb0.110,000INAA
Sc0.11000INAA
Se310,000INAA
Sm 0.110,000INAA
Sn0.02%20%INAA
Sr110,000ICP
Ta 0.510,000INAA
Tb0.510,000INAA
Th0.210,000INAA
Ti 0.01%10%ICP
U0.510,000INAA
V210,000ICP
W110,000INAA
Y 11,000ICP
Yb 0.210,000INAA
Zn  *1100,000ICP&INAA

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

+ Sulphide sulphur and soluble sulphates are extracted.

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

Assays are recommended for values which exceed the upper limits.

Reference:

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

Ultratrace-3 is a combination of our 1H package (INAA and multi-acid digestion ICP) combined with ICP-MS on the same solution we use for ICP. 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, 6100 or 9000 ICP/MS.

INAA

INAA (Instrumental Neutron Activation Analysis) is an analytical technique dependent on measuring gamma radiation induced in the sample by irradiation with neutrons. The primary source of neutrons for irradiation is usually a nuclear reactor. Each activated element emits a “fingerprint” of gamma radiation which can be measured and quantified. Routine multi-element analyses by INAA are performed on practically any material from the smallest sample which can be weighed accurately to very large samples.

A 30g aliquot, if available, is encapsulated in a polyethylene vial and irradiated along with flux wires at a thermal neutron flux of 7 x 10 12 ncm-2 s-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 and control standards, the decay-corrected activities are compared to a calibration developed from multiple certified international reference materials. 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 sample material is available.

“Near Total” Digestion – ICP

A 0.25g 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.

“Near Total” Digestion – ICP-MS

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.

Elements and Detection Limits (ppm)

Element Detection LimitUpper LimitReported By
Ag*0.0510,000INAA,ICP &ICP/MS
Al0.01%50%ICP
As0.510,000INAA
Au2 ppb30,000 ppbINAA
Ba *1100,000INAA & ICP/MS
Be *0.11,000ICP & ICP/MS
Bi *0.0210,000ICP &ICP/MS
Br0.55000INAA
Ca0.01%70%ICP
Cd *0.12,000ICP & ICP/MS
Ce0.110,000INAA & ICP/MS
Co *15,000INAA & ICP/MS
Cr *110,000INAA &ICP/MS
Cs *0.055,000INAA &ICP/MS
Cu *0.210,000ICP &ICP/MS
Dy0.15,000ICP/MS
Er0.11,000ICP/MS
Eu0.051,000INAA & ICP/MS
Fe0.01%70%INAA
Ga0.1500ICP/MS
Ge0.1500ICP/MS
Gd0.1500ICP/MS
Hf0.15,000INAA & ICP/MS
Hg10 ppb10,000 ppbICP/MS
Ho0.11,000ICP/MS
Ir5 ppb10,000 ppbINAA
In0.1100ICP/MS
K0.01%10%ICP
La0.510,000INAA & ICP/MS
Li0.510,000ICP/MS
Lu0.1100ICP/MS
Mg0.01%50%ICP
Element Detection LimitUpper LimitReported By
Mn1100,000ICP
Mo0.210,000ICP
Na0.01%20%INAA
Nb0.1500ICP/MS
Nd0.0110,000INAA & ICP/MS
Ni *0.5100,000INAA, ICP & ICP/MS
P0.001%10%ICP
Pb *0.55,000ICP &ICP/MS
Pr0.11,000ICP/MS
Rb *0.25,000INAA &ICP/MS
Re0.001100ICP/MS
S+0.01%20%ICP
Sb0.110,000INAA
Sc0.11,000INAA
Se *0.110,000INAA &ICP/MS
Sm0.1100INAA & ICP/MS
Sn1200ICP/MS
Sr0.21,000ICP/MS
Ta *0.110,000INAA & ICP/MS
Tb0.15,000INAA & ICP/MS
Te0.02500ICP/MS
Th *0.110,000INAA &ICP/MS
Ti0.01%10%ICP
Tl0.05500ICP/MS
Tm0.11,000IPC/MS
U *0.110,000INAA & ICP/MS
V210,000ICP
W110,000INAA
Y0.0110,000ICP/MS
Yb0.15,000INAA & ICP/MS
Zn *0.5100,000INAA, ICP &ICP/MS
Zr15,000ICP/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.

Ultratrace 5 is a combination of INAA with a 4-acid digestion ICP-MS. Some of the resistate elements are provided by INAA.

“Near Total” Digestion – ICP-MS

A 0.25g sample is digested at 260°C 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. This leach is partial for magnetite, chromite, barite, spinels, zircon and massive sulphides.

Digested samples are diluted and analyzed by 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.

INAA

INAA (Instrumental Neutron Activation Analysis) is an analytical technique dependent on measuring gamma radiation induced in the sample by irradiation with neutrons. The primary source of neutrons for irradiation is usually a nuclear reactor. Each activated element emits a “fingerprint” of gamma radiation which can be measured and quantified. Routine multi-element analyses by INAA are performed on practically any material from the smallest sample which can be weighed accurately to very large samples.

A 30 g aliquot, if available, is encapsulated in a polyethylene vial and irradiated along with flux wires at a thermal neutron flux of 7 x 10 12 ncm-2 s-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 and control standards, the decay-corrected activities are compared to a calibration developed from multiple certified international reference materials. 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 sample material is available.

Elements and Detection Limits (ppm except where noted)

ElementDetection LimitUpper LimitReported By
Ag*0.05100,000INAA& ICP/MS
As0.510,000INAA
Au2ppb30,000ppbINAA
Ba1100,000INAA& ICP/MS
Be0.11,000ICP/MS
Bi0.022,000ICP/MS
Br0.55,000INAA
Ca0.01%50%ICP/MS
Cd0.11,000ICP/MS
Ce0.110,000ICP/MS
Co0.15,000INAA & ICP/MS
Cr1100,000INAA
Cs*0.055,000INAA& ICP/MS
Cu0.210,000ICP/MS
Dy0.15,000ICP/MS
Er0.11,000ICP/MS
Eu0.05100ICP/MS
Fe0.01%50%INAA
Ga0.1500ICP/MS
Ge0.1500ICP/MS
Gd0.15,000ICP/MS
Hf0.15,000INAA
Hg10ppb10,000ppbICP/MS
Ho0.11,000ICP/MS
In0.1100ICP/MS
K0.01%5%ICP/MS
La0.110,000ICP/MS
Li0.5400ICP/MS
Lu0.1100ICP/MS
Mg0.01%10%ICP/MS
ElementDetection LimitUpper LimitReported By
Mn110,000ICP/MS
Mo0.0510,000ICP/MS
Na0.01%20%INAA
Nb0.1500ICP/MS
Nd0.110,000ICP/MS
Ni*0.5100,000INAA& ICP/MS
Pb0.55,000ICP/MS
Pr0.11,000ICP/MS
Rb0.25,000ICP/MS
Re0.001100ICP/MS
Sb0.110,000INAA
Sc0.11,000INAA
Se*0.110,000INAA& ICP/MS
Sm0.1100ICP/MS
Sn1200ICP/MS
Sr0.21,000ICP/MS
Ta*0.110,000INAA& ICP/MS
Tb0.1100ICP/MS
Te0.1500ICP/MS
Th*0.110,000INAA& ICP/MS
Tl0.05500ICP/MS
Tm0.11,000ICP/MS
U*0.110,000INAA& ICP/MS
V11,000ICP/MS
W110,000INAA
Y0.110,000ICP/MS
Yb0.15,000ICP/MS
Zn*0.5100,000INAA& ICP/MS
Zr15,000ICP/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.

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

Geochemical Exploration for Epithermal Deposits:

Aqua Regia “Partial” Digestion with Total Determinations of Resistive Elements by INAA

A 30g sample is analyzed by INAA and with an aqua regia digestion followed by ICP analysis.

INAA

INAA (Instrumental Neutron Activation Analysis) is an analytical technique dependent on measuring gamma radiation induced in the sample by irradiation with neutrons. The primary source of neutrons for irradiation is usually a nuclear reactor. Each activated element emits a “fingerprint” of gamma radiation which can be measured and quantified. Routine multi-element analyses by INAA are performed on practically any material from the smallest sample which can be weighed accurately to very large samples.

A 30g aliquot, if available, is encapsulated in a polyethylene vial and irradiated along with flux wires at a thermal neutron flux of 7 x 10 12 ncm-2 s-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 and control standards, the decay-corrected activities are compared to a calibration developed from multiple certified international reference materials. 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 sample material is available.

Aqua Regia Digestion – ICP

0.5g of sample is digested with aqua regia for 2 hours at 95 C. Sample is cooled then diluted with deionized water. The samples are then analyzed on a Perkin Elmer ICP for the 35 element suite. A matrix standard and blank are run every 13 samples.

A series of USGS-geochemical standards are used as controls. This digestion is near total for base metals; however it is only a partial digestion for silicates and oxides.

1EPI (Au + 14) Elements and Detection Limits (ppm)

ElementDetection LimitUpper LimitReported By
Ag *0.210,000INAA and ICP
As210,000INAA
Au5 ppb30,000 ppbINAA
Ba50100,000INAA
Cd0.55,000ICP
Cu110,000ICP
Fe0.02%75%INAA
Hg110,000INAA
ElementDetection LimitUpper LimitReported By
Mn220,000ICP
Mo210,000ICP
Ni110,000ICP
Pb25,000ICP
S+0.00%20%ICP
Sb0.210,000INAA
W410,000INAA
Zn110,000ICP

1EPI Enhanced (Au + 14) Elements and Detection Limits (ppm)

ElementDetection LimitUpper LimitReported By
Ag *0.210,000INAA and ICP
As0.510,000INAA
Au5 ppb30,000 ppbINAA
Ba5050,000INAA
Cd0.55,000ICP
Cu110,000ICP
Hg110,000INAA
Mn220,000ICP
ElementDetection LimitUpper LimitReported By
Mo210,000ICP
Ni110,000ICP
Pb25,000ICP
S+0.00%20%ICP
Sb0.210,000INAA
W410,000INAA
Zn110,000ICP

Notes: Extraction of each element by Aqua Regia Digestion is dependent on mineralogy.
+ Only sulphide sulphur is extracted.
* Element reported by multiple techniques if one or more technique may not be total.
Assays are recommended for values which exceed the upper limits.

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

A 30g sample is analyzed by INAA and with an aqua regia digestion followed by ICP-MS analysis.

INAA

INAA (Instrumental Neutron Activation Analysis) is an analytical technique dependent on measuring gamma radiation induced in the sample by irradiation with neutrons. The primary source of neutrons for irradiation is usually a nuclear reactor. Each activated element emits a “fingerprint” of gamma radiation which can be measured and quantified. Routine multi-element analyses by INAA are performed on practically any material from the smallest sample which can be weighed accurately to very large samples.

A 30g aliquot, if available, is encapsulated in a polyethylene vial and irradiated along with flux wires at a thermal neutron flux of 7 x 10 12 ncm-2 s-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 and control standards, the decay-corrected activities are compared to a calibration developed from multiple certified international reference materials. 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 sample material is available.

Aqua Regia Digestion – ICP-MS

Digested samples are diluted and analyzed by Perkin Elmer Sciex ELAN 6000, 6100 or 9000 ICP/MS. One blank is run for every 68 samples. An in-house control is run every 33 samples. Digested standards are run every 68 samples. After every 15 samples, a digestion duplicate is analyzed. Instrument is recalibrated every 68 samples.

1EPI/MS (Au + 23) Elements and Detection Limits (ppm)

ElementDetection LimitUpper LimitReported By
Ag *0.210,000INAA and ICP
As210,000INAA
Au5 ppb30,000 ppbINAA
Ba100100,000INAA and ICP
Bi0.11,000ICP/MS
Ca0.01%50%ICP
Cd0.55,000ICP
Cs210,000INAA and ICP/MS
Cu110,000ICP
Fe0.02%75%INAA
Ga110,000ICP/MS
Ge0.11,000ICP/MS
ElementDetection LimitUpper LimitReported By
K0.01%20%ICP
Mn220,000ICP
Mo210,000ICP
Ni110,000INAA and ICP
S0.00%20%ICP
Sb0.210,000INAA
Se0.11,000INAA and ICP/MS
Te0.11,000ICP/MS
Tl0.11,000ICP/MS

1EPI/MS Enhanced (Au + 23) Elements and Detection Limits (ppm)

ElementDetection LimitUpper LimitReported By
Ag *0.210,000INAA
As0.510,000INAA
Au5 ppb30,000 ppbINAA
Ba100100,000INAA
Bi0.11,000ICP/MS
Ca0.01%50%ICP
Cd0.55,000ICP
Cs210INAA
Cu110,000ICP
Fe0.02%75%INAA
Ga110,000ICP/MS
Ge0.11,000ICP/MS
Hg110,000INAA

Notes: Extraction of each element by Aqua Regia Digestion is dependent on mineralogy.
* Element reported by multiple techniques if one or more technique may not be total.
Assays are recommended for values which exceed the upper limits.

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