Metals in Sewage SludG™, ERA 160

APPLICATION NOTE

SUMMARY

The application note summarizes the digestion of ERA 160, a Metals in Sewage Sludge certified 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:	107% Arsenic 103% Mercury 105% Selenium

Related Resources

Soil Testing with ColdBlock

Soil Analysis with ColdBlock: Faster, Simpler and Equivalent to Standard Methods

Metals in Sewage Sludge

Industrial Sludge, NIST 2782

Boost Your Lab's Speed and Efficiency with ColdBlock

METHODOLOGY

Chiller temperature was set to -5°C
0.5g of each sample was weighed and placed into a ColdBlock Digestion vessel
10mL of 1:1 HNO₃ + 5mL 1:1 HCl were added, and the samples were digested at 70% power for 5 minutes
10mL HNO₃ was added and digested again at 60% power for 20 minutes (repeat this step if fuming continues)
3mL of 30% H₂O₂ was added slowly, and digested again at 60% for 10 minutes
5mL HCl was added and digested at 60% power for 10 minutes
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 ERA 160 after bulk up to 50mL

Results

ERA #160 Metals in Sewage SludG (lot:D122-160)
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	3228	3427	42.10	1.2%	106%
Antimony	108	124	4.16	3.4%	115%
Arsenic	127	136	1.89	1.4%	107%
Barium	698	718	23.6	3.3%	103%
Beryllium	78.3	80.5	2.90	3.6%	103%
Cadmium	86.7	85.4	2.71	3.2%	99%
Calcium	39519	40469	1524.6	3.8%	102%
Chromium	72.4	74.7	1.72	2.3%	103%
Cobalt	9.9	10.2	0.19	1.9%	103%
Copper	812	809	19.1	2.4%	100%
Iron	23934	24802	811.03	3.3%	104%
Lead	105	110	2.33	2.1%	104%
Magnesium	3261	3365	135	4.0%	103%
Manganese	558	595	16.0	2.7%	107%
Mercury	53.6	55.0	2.22	4.0%	103%
Molybdenum	96.5	92.7	2.71	2.9%	96%
Nickel	47.7	49.0	1.74	3.5%	103%
Potassium	4293	4279	117.7	2.8%	100%
Selenium	65.7	68.8	1.95	2.8%	105%
Silver	89.3	90.1	1.81	2.0%	101%
Sodium	2986	3177	96.17	3.0%	106%
Thallium	100	102	0.943	0.9%	102%
Vanadium	37.0	39.1	0.87	2.2%	106%
Zinc	821	758	24.2	3.2%	92%

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.