Industrial Sludge, NIST 2782

APPLICATION NOTE

SUMMARY

The application note summarizes the digestion of NIST 2782, an Industrial Sludge 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:	109% Arsenic 103% Cadmium 102% Antimony

Related Resources

Soil Testing with ColdBlock

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

Metals in Sewage SludG™, ERA 160

Metals in Sewage Sludge

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 NIST 2782 after bulk up to 50mL

Results

Industrial Sludge, NIST 2782
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
Arsenic	144	157	3.19	2.2%	109%
Aluminum	1468	1503	41.12	2.8%	102%
Antimony	2.07	2.12	0.420	20%	102%
Barium	136	153	2.14	1.6%	113%
Cadmium	2.14	2.20	0.112	5.3%	103%
Calcium	4544	4624	169.6	3.7%	102%
Chromium	65.4	69.4	1.46	2.2%	106%
Cobalt	52.2	53.5	1.86	3.6%	103%
Copper	2288	2511	66.06	2.9%	110%
Iron	247576	258116	7041	2.8%	104%
Lead	491	553	5.69	1.2%	113%
Magnesium	468	482	23.8	5.1%	103%
Manganese	243	264	8.64	3.6%	109%
Mercury	1.22	1.27	0.0509	4.2%	104%
Molybdenum	5.39	5.95	0.374	6.9%	110%
Nickel	95.54	106.2	4.65	4.9%	111%
Potassium	88	97	6.1	7.0%	111%
Silver	26.98	28.47	3.212	11.9%	106%
Sodium	2539	2637	75.98	3.0%	104%
Vanadium	10.7	14.4	0.678	6.3%	135%
Zinc	1143	1129	46.91	4.1%	99%

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.