Digestion of Trace Metals in Paint Chips, Cadmium & Lead in Paint, and Lead in Powdered Paint

APPLICATION NOTE

Digestion of Trace Metals in Paint Chips, Cadmium & Lead in Paint, and Lead in Powdered Paint

SUMMARY

The application note summarizes the digestion of 3 Paint Reference Materials, Trace Metals in Paint Chips, Cadmium & Lead in Paint and Lead in Powdered Paint using ColdBlock Digestion CB15S Technology.

Instrument:	ColdBlock CB15S sample digester technology, chiller, ICP-OES, ICP-MS
Published:	August 2022
Digestion Time:	20 Minutes
Acid Used:	HNO₃ & HCl
Average ColdBlock Recovery vs. CRM:	93% Cadmium 97% Chromium 102% Lead

METHODOLOGY

Chiller temperature was set to -5 °C
0.5g of each sample was weighed and placed into a ColdBlock™ Digestion vessel
12ml HNO3 was added, and mixed with sample
Sample was digested at 80% power for 10 minutes
4mL HCl was added, and sample was digested again at 80% power for 10 minutes
Sample was cooled and bulked to 50mL using 2% HNO3 v/v

DISCUSSION

During the digestion, the samples started climbing up the test tube but fell back down once they hit the cooling zone
After 20 minutes the samples turned the same color corresponding to the original paint color and some solid material remains

From left to right : Cd & Pb in Paint, Trace Metals in Paint Chips & Lead in Powdered Paint after 20 minute digestion

Cd & Pb in Paint is a matrix reference material intended for QC verification and method development of contaminated surface coated painted items such as toys, furniture etc. Lead in Powdered Paint, SQC074 is a certified reference material intended for method development purposes. Trace Metals in Paint Chips is a certified material of contaminated paint chips sourced from an industrial blasting process.

Results

Trace Metals in Paint Chips – CRM013
Method:	0.5g	12mL HNO3 – Digest at 80% for 600 seconds – Add 4mL HCl and digest again for 600 seconds. Bulk to 50mL with 2% HNO3
Element	Certified Value mg/kg	ColdBlock A mg/kg	ColdBlock B mg/kg	ColdBlock C mg/kg	ColdBlock Average (mg/kg)	Stdev	%RSD	% Recovery
Cd	37.8	32	34.5	38.4	35.0	1.3	3.6%	93%
Cr	618	623	586	593	601	19	3.1%	97%
Pb	643	631	687	643	654	28	4.3%	102%

Cadmium & Lead in Paint
Method:	0.5g	12mL HNO3 – Digest at 80% for 600 seconds – Add 4mL HCl and digest again for 600 seconds. Bulk to 50mL with 2% HNO3
Element	Certified Value mg/kg	ColdBlock A mg/kg	ColdBlock B mg/kg	ColdBlock C mg/kg	ColdBlock Average mg/kg)	Stdev	% RSD	% Recovery
Cd	219.4	213.8	222.6	226.1	220.8	4.4	2.0%	101%
Pb	224.2	230.1	238.7	234.6	234.5	4.3	1.8%	105%

Lead in Powdered Paint – SQC074
Method:	0.5g	12mL HNO3 – Digest at 80% for 600 seconds – Add 4mL HCl and digest again for 600 seconds. Bulk to 50mL with 2% HNO3
Element	Certified Value mg/kg	ColdBlock A mg/kg	ColdBlock B mg/kg	ColdBlock C mg/kg	ColdBlock Average mg/kg)	Stdev	% RSD	% Recovery
Pb	1125	1119	1134	1075	1109	7.5	0.7%	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.