Determination of Selenium Concentration in Sixty Five Reference Materials for Geochemical Analysis by GFAAS after Separation with Thiol Cotton

Abstract

Selenium has been determined in sixty five geological reference materials of different origins by graphite furnace atomic absorption spectrometry. Samples were decomposed with a mixture of nitric and hydrofluoric acids. Selenium was reduced to SeIV with hydrochloric acid, and then fixed and separated from the matrix on thiol cotton. After digestion of the thiol cotton in hot nitric acid, the Se concentration was measured using palladium and magnesium nitrates as a matrix modifier. The limit of determination was 0.02 μg g−1, the precision of the results (relative standard deviation of 3 to 8 replicates) varied from 2.6 to 17.7% with an average of 7.9% in the range 0.02‐42.7 μg g−1 and was similar to the value obtained for synthetic samples. Our results are in good agreement with available literature values.

Determination of total selenium in geological samples by HG-AFS after concentration with thiol cotton fiber

“…Although hydride-generation atomic fluorescence spectrometry is of sufficient sensitivity for the determination of selenium in geological materials at the g/g level, serious interference is usually encountered, arising from the diverse and complicated properties of the matrices. Yu Muqing and Liu Guiqin (1983), Shan Xiaoquan and Hu Kaijing (1985) and Marin et al (2001) determined total selenium in water, rocks, minerals, and standard reference materials after concentration with thiol cotton fiber with an attempt to control the interference.…”

Étude du comportement géochimique du sélénium, sa relation avec le soufre dans le bushveld (Afrique du sud) et développement des techniques analytiques /

“…(1997) Holland Pekhat (1997) Marin et al (2001) Schnepfe and Flanagan (1973) Chan ( Erzinger and Pucheit (1980) Kolmer and Raptis (1983) Chan and Baig (1984) Terashtma and imai (2000) Van der Sloot et al (1982) Chan (1985) Marin era/. (2001) Meyer (1988) UQAC (this study) Savard et al (2006) UQAC (this study) Hannington and Gorton (1991) UQAC (this study) Constantin (2006) UQAC (this study) Gladney and Knab (1981) …”

“…The development of Se pre-concentration using the TCF technique was based on the protocols of XiaoQuan and Kai-Jing (1985) and Marin et al (2001), and was modified for determinations by INAA by Savard ef al. (2006).…”

“…Although there are variation in TCF [13][14][15][16][17][18][19][20][21][22], the method used in this study is similar to Marin et al [21]: 10 g of commercial cotton, 53 ml of thioglycollic acid (mercaptoacetic acid), 35 ml of acetic anhydride, 16.5 ml of acetic acid and 0.15 ml of sulfuric acid (H2SO4) (all ACS grade) were mixed in an Erlenmeyer flask and placed in a water bath (40 °C) for 4-5 days. The mixture was stirred every day.…”

“…The thiol cotton fiber (TCF) originally developed by Nishi et al [13] for preconcentration of mercury is known today for its affinity with 19 elements [14,15], TCF is a strong smelling white powder, notably able to collected Se IV from HC1 [14,16]. TCF preparation is easy, relatively stable, well known, inexpensive and has been used in some previous works [13][14][15][16][17][18][19][20][21][22]. Elements collected on TCF have been analyzed after destruction of TCF with varied instrument such as graphitefurnace atomic absorption (GFAA), ICP-MS and ICP-AES.…”