Distributor login
Contact us

APPLICATION NOTE

Estuarine Sediment – NIST 1646a

SUMMARY

The application note summarizes the digestion of NIST 1646a, an Estuarine Sediment standard reference material using ColdBlock Digestion Pro Series Technology.

Instrument:

ColdBlock CBM, chiller, ICP-OES, ICP-MS (with CRC technology)

Published:March 2025
Digestion Time:45 Minutes
Acid Used:

HNO3, HCl & H2O2

Average ColdBlock Recovery vs. CRM:
  • 102% Barium
  • 107% Chromium
  • 102% Molybdenum

METHODOLOGY

  1. Chiller temperature was set to -5°C
  2. 0.5g of each sample was weighed and placed into a ColdBlock Digestion vessel
  3. 10mL of 1:1 HNO3 + 5mL 1:1 HCl were added, and the samples were digested at 70% power for 5 minutes
  4. 10mL HNO3 was added and digested again at 60% power for 20 minutes (repeat this step if fuming continues)
  5. 3mL of 30% H2O2 was added slowly, and digested again at 60% for 10 minutes
  6. 5mL HCl was added and digested at 60% power for 10 minutes
  7. Samples were cooled and bulked to 50mL using ultrapure water

DISCUSSION

  • This method yielded data comparable to EPA 3050B standards in just 45 minutes
  • The addition of HCl in the final step of the digestion helps keep certain elements such as antimony and silver solubilized
  • This method is not appropriate for standard ICP-MS instruments that are not equipped with Collision/Reaction Cell technology

15 samples of NIST 1646a after bulk up to 50mL

Results

Estuarine Sediment, NIST 1646a

Method:

0.5g – Add 10mL 1:1 HNO3 + 5mL 1:1 HCl, digest at 70% for 5 minutes, then add 10mL HNO3 and digest at 60% for 20 minutes (repeat this step if fuming continues) Add 3mL of 30% H2O2, slowly and digest again @ 60% for 10 minutes, then add 5mL HCl and digest again @ 60% for 10 minutes. Cool and bulk to 50mL with ultrapure water

Element

*Reference Value (mg/kg) n=5

ColdBlock Average (mg/kg) n=16

ColdBlock Stdev

ColdBlock
% RSD

ColdBlock % Recovery vs SW-846 3050B

Aluminum

7075

7182

206

2.9%

102%

Antimony

0.72

0.81

0.04

5.1%

112%

Arsenic

4.69

6.12

0.28

4.5%

130%

Barium

21.2

21.7

1.03

4.7%

102%

Cadmium

0.127

0.142

0.00

2%

112%

Calcium

3578

3711

162

4.4%

104%

Chromium

24.4

26.2

2.15

8.2%

107%

Cobalt

3.2

3.4

0.13

3.8%

108%

Copper

9.98

9.96

0.13

1.3%

100%

Iron

15330

17111

849

5.0%

112%

Lead

5.26

4.99

0.3

5.1%

95%

Magnesium

2972

3347

35

1.1%

113%

Manganese

117.3

125.2

1.7

1.3%

107%

Mercury

0.03

0.05

0.0039

8.5%

142%

Molybdenum

1.81

1.84

0.15

8.4%

102%

Nickel

18.8

21.9

2.27

10.4%

116%

Potassium

2235

2273

96

4.2%

102%

Sodium

3819

3913

254

6.5%

102%

Vanadium

20.95

22.90

1.10

4.8%

109%

Zinc

36.72

35.92

2.06

5.7%

98%

Click here to download the Application Note in PDF format.

Join our monthly e-newsletter for expert tips, updates, and exclusive content delivered straight to your inbox.

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