This method uses a vapor generation accessory to determine arsenic in non-silicate geological ore samples.
The document compares two digestion methods for analyzing arsenic in geological samples: aqua regia (nitric acid/hydrochloric acid) and hydrochloric acid/hydrogen peroxide. These methods are effective only for arsenic not bound within a silica matrix.
Measurements were performed using an Agilent SpectrAA-40P spectrometer equipped with a Vapor Generation Accessory (VGA-76). The note details sample preparation, stabilization techniques using potassium iodide, and provides data on analytical ranges, calibration graphs, and recovery studies for both digestion methods.
| Spectrometer Model | Agilent SpectrAA-40P |
|---|---|
| Accessory Model | Vapor Generation Accessory (VGA-76) |
| Sample Changer Model | Programmable Sample Changer (PSC-56) |
| Analytical Range 197.2 nm | 0-100 ng/mL |
No, neither digestion method can extract arsenic from within a silica matrix; hydrofluoric acid is required for that.
Solid potassium iodide should be added to stabilize solutions, reducing As(V) to As(III).