Analysis of Metals in Marine Sediments by Microwave Extraction and Flame, Hydride Generation and Cold Vapour Atomic-Absorption Spectrometry

Abstract

A simple and fast metal extraction method that combines closed vessels and microwave heating for the simultaneous extraction often selected heavy metals (As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Zn) from marine sediments is proposed. Digestion conditions, i.e. power and times microwave irradiation, reagent extractant, sample amount, were optimized to recover the potentially available metallic fraction not bound in silicates. A nitric acid and two step microwave program was established. 140 MARTINEZ-GARCIA ET AL. The resulting solutions were analyzed by flame (FAAS), hydride generation (HG-AAS) and cold vapour (CV-AAS) atomic absorption spectrometry. Quantifications were made using direct calibration with aqueous standards. The recoveries of the spiked samples investigated ranged from 89 to 113%. The results obtained from analyzing the BCR certified reference sediment CRM 277 Estuarine Sediment were in good agreement with the certified values (93-105%), except for low values for chromium (79%). The relative standard deviations for the determination of metals were less than 4 %. Finally, the technique designed herein was applied to sediment samples from La Coruna estuary, NW Spain.

Determination of Pb and Cd in road dusts over the period in which Pb was removed from petrol in the UK

“…The procedure used in this study was derived from procedures recommended by other workers. [30][31][32][33][34][35] (i) A weight of 0.1 g of road dust sample dried to a constant weight was placed in a PTFE bomb before 8 ml HNO 3 and 2 ml HCl were added. (ii) The sample was allowed to digest by heating the bomb in the oven for 3 h at 150 uC, followed by cooling.…”

Acoplamento cromatografia gasosa - espectrometria de absorção atômica em estudos de especiação: uma revisão

“…Não está no escopo deste artigo a discussão do pré-tratamento de amostras com vistas à especiação, uma vez que boas revisões podem ser encontradas na literatura [106][107][108][109] . Entretanto, deve-se apontar que extrações assistidas por microondas com o uso de soluções ácidas diluídas [110][111][112][113][114] , assim como a microextração em fase sólida (SPME) [115][116][117][118][119] , vem mostrando ser procedimentos bastante promissores.…”