Studies on the Colorimetric Determination of Silica in Rocks. Part II A Rapid Method of Determination of Silica in Presence of Phosphorus
| Main Author: | R.C.SARKAR |
|---|---|
| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 1981
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/6352752 |
Daftar Isi:
- Analytical Chemistry Division. Bhabha Atomic Research Centre. Trombay, Bombay-400 085 Manuscript received 30 May 1980, revised 15 November 1980, accepted 29 January 1981 A rapid differential spectrophotometric method for the determination of silica as β-silicomolybdic acid is presented for routine analysis of rocks and geological materials. After full development of the silicomolybdic acid in weakly acid medium, the solution is made strongly acid resulting in the destruction of the colour due to phosphomolybdic acid, the former remaining unaffected. As the intrinsic instability of the β-isomer precludes the use of silica standard as a reference solution, potassium chromate solutionis preferentially used for differential measurement using two silica standards to bracket the absorbance of the sample. Appreciable amounts of P, Ti, Fe(II) and low amounts of As, Ge and V commonly present in silicate rocks, do not interfere.