APPLICATION NOTE

NRC SPIN-1 Air Dried Spinach

SUMMARY

The application note summarizes the digestion of SPIN-1, an air-dried spinach powder Certified Reference Material using
ColdBlock™ Digestion Pro Series Technology.

Instrument: ColdBlock CBM sample digester, chiller & ICP-MS
Published: March 2023
Digestion Time: 10 Minutes
Acid Used: HNO3 & H2O2
Average ColdBlock Recovery vs. CRM:
  • 111% Arsenic
  • 96% Cadmium
  • 96% Lead

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. 15 mL of HNO3 + 2mL H2O2 was added
  4. Sample was digested at 70% power for 10 minutes
  5. Samples were cooled and bulked to 40mL using 2% HNO3 + 0.5% HClv/v

DISCUSSION

  • Samples are mostly clear after digestion, and minor of amount of material settled on the bottom of the tube after bulking
  • Samples were filtered prior to analysis
SPIN-1 was prepared at the National Research Council Canada from food grade air dried spinach powder SPIN-1; Air Dried Spinach Powder; National Research Council Canada ; Ottawa, Ontario Canada (June, 2019)

Results

SPIN-1 (Air Dried Spinach Powder)
Element Reference Value (mg/kg) 95% Confidence Limits Sample A Sample B Sample C Average (ppm) Stdev % RSD % Recovery
Low High
As 0.7 0.58 0.82 0.7 0.8 0.8 0.8 0.029 3.7% 111%
Se 0.062 0.03 0.094 0.056 0.074 0.077 0.069 0.009 13.4% 111%
Cd 0.265 0.235 0.295 0.227 0.265 0.268 0.254 0.019 7.4% 96%
Pb 2.33 1.99 2.67 2.24 2.31 2.16 2.24 0.063 2.8% 96%
Sr 140.8 130.9 150.7 151.5 155.6 158.0 155.0 2.717 1.8% 110%
Zn 40.7 38.7 42.7 45.2 41.7 36.6 39.1 2.515 6.4% 96%