ODREĐIVANJE SPECIJA ANORGANSKOG ARSENA U EKSTRAKTIMA ZEMLJIŠTA JEDNOSTAVNOM SPEKTROFOTOMETRIJSKOM METODOM

• Published in: Radovi Šumarskog fakulteta Univerziteta u Sarajevu Vol. 41; no. 1; pp. 39 - 58
• Main Authors: Tahirović, Azra, Čopra-Janićijević, Amira, Kalcher, Kurt
• Format: Journal Article
• Language: English
• Published: 01-06-2011
• ISSN: 1512-5769; 2490-3183
• DOI: 10.54652/rsf.2011.v41.i1.139

UDK 631.4:546.19
A simple and inexpensive method for the determination of inorganic As(III) and As(V) at low ppb levels was developed. The method is based on formation of hydride from a sample solution and its reaction with mercury bromide on a solid support. Formation of a yellow-brownish product was optically detected.
Amidosulfonic acid was used as a reaction medium for determination of total inorganic arsenic, while citrate buffer (0.1 mol/dm3, pH=5.5) was used as a reaction media for determination of As(III) alone. As(V) was calculated as a difference of total inorganic arsenic and As(III).
This method has been applied to soil extracts. Extraction of inorganic arsenic from soil samples was done in three-step sequential extraction with the following extractants: NH4H2PO4 (0.05 mol/dm3); NH4-oxalate buffer (0.2 mol/dm3, pH=3.25); and mixture of NH4-oxalate buffer (0.2 mol/dm3) and ascorbic acid (0.1 mol/dm3) at pH=3.25. The method was suitable for determination of inorganic arsenic species in soil extracts covering concentration range of the analyte between 0.2 - 20 ppb.