Abstract
We developed an online continuous-flow spectrophotometric method for determination of ferrous iron and total iron mass fractions in various types of geological certified reference materials (CRMs) using a Schlenk line technique to exclude oxygen during the digestion process. The continuous-flow technique enabled automatic, reliable and real-time analysis, and decreased sample and reagent consumption. The Schlenk line expels air to prevent oxidation during sample digestion. Compared with traditional spectrophotometric procedures, this analytical procedure is easier, more automated and more accurate. The composition of the acid matrix and time used to dissolve the samples were carefully examined. The procedure was tested on 186 replicates of twenty-seven rock CRMs, and the results showed good agreement with the compiled values from the literature. Based on the statistical data, the proposed procedure was found to be accurate within 0.12% m/m for ferrous iron mass fraction and 0.084% m/m for total iron mass fraction compared with the certified/recommended values. The proposed procedure is accurate, reproducible and has a high throughput (ten samples per hour).
| Original language | English |
|---|---|
| Pages (from-to) | 785-804 |
| Number of pages | 20 |
| Journal | Geostandards and Geoanalytical Research |
| Volume | 44 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Dec 2020 |
Keywords
- Schlenk line
- ferrous iron
- flow-based
- spectrophotometric
- total iron