University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Reference Material -> USGS -> PCC-1 -> Peridotite

Citations 2

"Preliminary Studies Of Iron Speciation (Fe2+ And Fe3+) In Peat Samples Using Polarography"
Anal. Sci. 2000 Volume 16, Issue 7 Pages 751-756
Paavo Perämäki, Mia Kumpumäki, Ilkka Välimäki, Ritva Heikknen

Abstract: Current-sampled (tast) polarography was used in the determination of the two iron oxidation states Fe2+ and Fe3+ in peat samples. The iron couple was reversible in the 0.1 mol L-1 citrate-supporting electrolyte used. The total iron concentration in the samples was determined by differential pulse polarography. Sample decomposition was done in a nitrogen atmosphere by hydrofluoric acid and sulfuric acid. The accuracy of the determinations was verified by spiking experiments and analyzing in-house standards (Geological Survey of Finland) RS 31 (Rapakivi granite), RS 71 (Diabase) and certified reference material PCC-1 (Peridotite, U.S. Geological Survey). The method, developed for this purpose, proved to be reasonably accurate.
Iron(2+) Iron(III) Polarography Reference material Interferences Optimization

"Spectrophotometric Determination Of Silicon In Silicate Rocks By Flow Injection Analysis"
Anal. Sci. 1988 Volume 4, Issue 5 Pages 523-525

Abstract: A system is described and illustrated for flow injection spectrophotometric determination of Si. Powdered silicate rock (25 mg) is decomposed with 0.5 mL of HCl and 0.25 mL of HF by repeated (x3) heating and cooling for 1 and 5 min, respectively. After cooling and addition of 5 mL of 4% H3BO3 solution, the mixture is diluted with water. A 65 µL portion is injected into the carrier stream (0.6 M HCl, 2.45 mL min-1), which is then mixed with 3% (NH4)6Mo7O24 solution (2.45 mL min-1). The mixed solution then passes to a 200-cm reaction coil maintained at 45°C, and the absorbance is measured at 415 nm in a flow-through cell. The method is suitable for determination of 200 to 380 µg g-1 of Si. Results for determination of Si in 22 standard rock samples agreed with certified values. The coefficient of variation (n = 5) was 0.4%.
Silicon Sample preparation Spectrophotometry Heated reaction Reference material