APPLICATION NOTE

Apple Leaves – NIST 1515

SUMMARY

The application note summarizes the digestion of NIST 1515, an apple leaves standard reference material using ColdBlock™ Digestion Pro Series Technology.
Instrument:ColdBlock CBM (with quartz test tubes), chiller, ICP-MS & ICP-OES
Published:July 2024
Digestion Time:20 Minutes
Acid Used:HNO3 & H2O2
Average ColdBlock Recovery vs. CRM:
  • 103% Boron
  • 100% Phosphorus
  • 99% Potassium

METHODOLOGY

  1. Chiller temperature was set to -5°C
  2. 0.5g of each sample was weighed and placed into a quartz ColdBlock™ Digestion vessel
  3. 10 mL of HNO3 was added
  4. Sample was digested at 65% power for 20 minutes
  5. 2mL of ≥ 30% H2 O2 was added slowly
  6. Samples were cooled and bulked to 40mL using 2% HNO3 v/v

DISCUSSION

  • Samples were digested in triplicate
  • Samples were filtered prior to analysis by ICP-MS
  • The NIST methods used for determination of certified Aluminum values included INAA & ICP-OES using HNO3/HF/HClO4 digestion, so Aluminum recovered slightly low (~70%) using HNO3 & H2O2
  • To improve the recovery the Aluminum, a second method was examined that included the addition of 1mL HF (10mL HNO3 + 1mL HF 65% power for 20 minutes, then slowly add 2mL of 30% H2 O2 ) See Table 2 for results
  • NIST 1515 consists of dried apple leaves of the Golden Delicious and Rome varieties

NIST 1515 after bulk up to 40mL

Results

Table 1 – Results of HNO3 & H2O2 digestion – NIST 1515 Apple Leaves
 Method:  0.5g         10mL HNO3 65% power for 20 minutes, then slowly add 2mL of 30% H2O2
 Element Consensus Value (ppm)  +/-  Sample A Sample B Sample C Average (ppm) Stdev RSD Recovery
 B 27.6 2.8 26.8 29.0 29.7  28.5 1.3 4.4% 103%
 Ba 48.8 2.3  44.8 51.8 48.2 48.3 2.8 5.9% 99%
Ca 15250  100 14001 16218 15042 15087 906 6.0% 99%
 Cd 0.0132 0.0015 0.0148 0.0137 0.0125 0.0137 0.001 6.9% 104%
 Cu 5.69 0.13 5.81 5.74 5.44 5.66 0.2 2.8% 100%
 Fe 82.7 2.6  82.6 85.3 92.5 86.8 4.2 4.8% 105%
 Hg 0.0432 0.0023  0.0423 0.0418 0.0426 0.0422 0.0004 0.9% 98%
 K 16080 210 14670 17110 15878 15886 996.2 6.3% 99%
 Mg  2710 120 2510 2929 2699 2713 171 6.3% 100%
 Mn 54.1 1.1 59.1 59.4 55.0 57.8 2.0 3.5% 107%
 Mo  0.095 0.011 0.108  0.106   0.105   0.106 0.001  1.2%  112%
 P  1593 68 1572 1585 1617 1591 18.9  1.2%  100%
 Pb  0.47 0.024 0.48 0.48  0.44  0.47  0.02  4.0% 99%
 Rb 10.2 1.6 9.5 9.5 9.2 9.4  0.1  1.4% 92%
 Sr 25.1 1.1 21.9 25.5 23.9 23.8 1.5 6.1% 95%
 V 0.254 0.027 0.300 0.282 0.298 0.293 0.01 2.8% 115%
 Zn 12.45 0.43 13.20 12.28 12.28 12.59 0.4 3.4% 101%
Table 2 – Results of HNO3 + HF & H2O2 digestion (to improve recovery of Aluminum)
 Method:  0.5g 10mL HNO3 + 1mL HF power for 20 minutes, then slowly add 2mL of 30% H2O2
 Element Consensus Value (ppm)  +/-  Sample A Sample B Sample C Average (ppm) Stdev RSD Recovery
Al 284.5 5.8 249.8 285.2 246.1 260.4 17.6 6.8% 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.