Research Article
Influence of Digestion Procedure and Residual Carbon on Manganese, Copper, and Zinc Determination in Herbal Matrices by Atomic Absorption Spectrometry
Table 5
Expanded combined uncertainties and relative standard uncertainties for particular contributions calculated for all methods and metal concentrations.
| Method | Relative standard uncertainty | Expanded combined uncertainty µg g−1 | CRM mass sample | Volumetric flask | Pipette | Standard solutions concentration | Mn | Zn | Cu |
| Ia | 0.0002 | 0.0016 | 0.0005 | 0.002 | 20.4 | 4.11 | 1.11 | Ib | 15.4 | 3.34 | 1.03 | Ic | 23.1 | 2.83 | 1.39 | Id | 20.6 | 2.06 | 1.13 | Ie | 18.0 | 2.57 | 0.77 | If | 21.2 | 2.57 | 1.08 | Ig | 23.1 | 2.31 | 0.67 |
| II | 0.0002 | 0.0012 | 0.0005 | 0.002 | 15.4 | 5.40 | 1.23 | III | 0.0001 | 28.3 | 4.37 | 1.29 | IV | 18.0 | 3.60 | 1.54 | V | 18.0 | 2.83 | 0.95 |
| VI | 0.0002 | 0.0016 | 0.0005 | 0.002 | 18.0 | 3.86 | 1.16 | VII | 0.0012 | 23.1 | 2.83 | 0.77 | VIII | 0.0001 | 23.1 | 2.83 | 1.29 | IX | 0.00005 | 0.001 | 25.7 | 2.31 | 1.00 |
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Pipette volume = 10 mL; concentrations of all Mn, Zn, and Cu standard solutions were c = 1.0000 mg L−1.
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