Determination of Cd, Pb and As in sediments of the Sava river by electrothermal atomic absorption spectrometry

Abstract

The applicability of nitric acid, palladium nitrate and a mixture of palladium and magnesium nitrate as matrix modifiers was estimated for the accurate and reproducible determination of cadmium (Cd), lead (Pb) and arsenic (As) in sediments of the Sava River by electrothermal atomic absorption spectrometry, ETAAS. Decomposition of the samples was done in a closed vessel microwave-assisted digestion system using nitric, hydrochloric and hydrofluoric acids, followed by the addition of boric acid to convert the fluorides into soluble complexes. The parameters for the determination of Cd, Pb and As in sediments were optimised for each individual element and for each matrix modifier. In addition, two sediment reference materials were also analysed. In determination of Cd and Pb, nitric acid was found to be the most appropriate matrix modifier. The accurate and reliable determination of Cd and Pb in sediments was possible also in the presence of boric acid. The use of a mixture of palladium and magnesium nitrate efficiently compensated for matrix effects and enabled the accurate and reliable determination of As in the sediments. Quantification of Cd and As was performed by calibration using acid matched standard solutions, while the standard addition method was applied for the quantification of Pb. The repeatability of the analytical procedure for the determination of Cd, Pb and As in sediments was ±5 % for Cd, ±4 % for Pb and ±2 % for As. The LOD values of the analytical procedure were found to be 0.05 mg/kg for Cd and 0.25 mg/kg for Pb and As, while the LOQ values were 0.16 mg/kg for Cd and 0.83 mg/kg for Pb and As. Finally, Cd, Pb and As were successfully determined in sediments of the Sava River in Slovenia.

Distribution and accumulation of heavy metals in the water and sediments of the River Sava

“…Notwithstanding the investigations performed on the upper stretches of River Sava in Slovenia and Croatia, 9,10 little attention has been paid to the quality of its water in Serbia. It drains 95.700 km 2 of land in former Yugoslavia, before entering the Danube at Belgrade in Serbia.…”

Transport and storage of heavy metals in the Sava river basin in Serbia

“…[10][11][12] In a previous paper, 13 the results of the distribution and accumulation of heavy metals in the water and sediments of the Sava River displayed seasonal fluctuations, which were attributed mainly to natural processes. The sediment studies were performed mainly because sediments are receptors in water bodies.…”

Trace Arsenic Determination in a TiO2 Pigment Matrix Using Electrothermal Atomic Absorption Spectrometry

“…13,14 Potential chemical modifiers proposed previously were noble metals with high melting points, such as palladium (Pd), platinum, iridium, rhodium, tantalum, titanium, tungsten, lanthanum, arsenic, and ruthenium. 9,[15][16][17][18][19][20][21][22] Furthermore, elements that form carbides such as molybdenum, hafnium, niobium, tungsten, tantalum, and zirconium, as well as NH 4 HPO 4 -Mg(NO 3 ) 2 , nitric acid, and silver nanoparticles have also been suggested. 21,23,24 How exactly the chemical modifier works is a matter of debate.…”