APPLICATION NOTE

OREAS 239 Large Sample Size Gold & Base Metals

SUMMARY

The application note summarizes the digestion of OREAS 239, a gold ore certified reference material using ColdBlock Digestion Technology.

Instrument:ColdBlock CBL Pro Series, chiller, ICP-OES & ICP-MS
Published:October 2025
Digestion Time:20 Minutes
Acid Used:HNO3, HCl
Average ColdBlock Recovery vs. CRM:
  • 99% gold
  • 104% arsenic
  • 103% copper

METHODOLOGY

  1. Chiller temperature was set to -5 °C
  2. 30g of each sample was weighed in triplicate and placed into ColdBlock digestion vessels
  3. 90mL of HNO3 was added slowly, followed by 30mL of HCl
  4. Samples were digested at 70% power for 20 minutes
  5. Sample was cooled and bulked to 200mL using 20% HCl v/v

DISCUSSION

  • Samples were diluted and analyzed for gold and silver by ICP-MS and base metals by ICP-OES
  • Samples were left to settle overnight. Filtration may also be used
  • Gold recovery was calculated using certified fire assay value

Results

OREAS 239, Gold Ore

Method:

30g – Add 90mL HNO3 + 30mL HCl and digest at 70% power for 20 minutes. Let cool, and bulk to 200mL with 20% HCl v/v

Element

Certified Value (ppm)

ColdBlock Result A (ppm)

ColdBlock Result B (ppm)

ColdBlock Result C (ppm)

Average (ppm)

 Stdev

% RSD

ColdBlock % Recovery vs Certified Value

Au

3.55

3.55

3.47

3.57

3.53

0.05

1.5%

99%

Ag

0.244

0.246

0.241

0.244

0.253

0.006

2.5%

101%

As

708

709

721

775

735

35

4.8%

104%

Cu

26.8

26.4

27.6

28.6

27.6

1.1

4.0%

103%

Co

12.1

13.2

12.9

12.6

12.9

0.3

2.1%

107%

Fe

33600

35819

35033

35092

35315

438

1.2%

105%

Mn

220

222

218

225

222

3.6

1.6%

101%

Ni

55

60

59

63

61

2.1

3.4%

111%

Pb

10.9

10.7

10.8

10.7

10.7

0.06

0.5%

98%

Sb

518

508

533

509

517

14.2

2.8%

100%

Zn

75

82

77

79

79

2.3

2.9%

106%

Click here to download the Application Note in PDF format.

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ColdBlock Technologies Inc.
4551 Zimmerman Ave
Niagara Falls, ON L2E 3M5
info@coldblock.ca