Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to measure the concentrations of cobalt, tantalum, titanium, vanadium and chromium in solutions of tungsten carbide. The main advantage of the method described here lies in the speed, convenience and effectiveness of the dissolution procedure. Aliquots of powdered tungsten carbide were dissolved in a solution of 5% aqua...

This manuscript describes a new protocol for determination of Pa/Th/U in marine sediments. It is based on microwave-assisted digestion and represents an important reduction of working time over conventional hot-plate digestion methods, and the use of HClO(4) is avoided. Although Th and U are completely dissolved with a first microwave step, around 40% of (231)Pa remains undissolved, and a short...

Foram comparados vários procedimentos de preparo de amostras, isto é, decomposição total de uma mistura HNO3/H2O2 em placa de aquecimento, decomposição parcial por meio de solubilização em aqua regia e diluição com solução de HNO3 de baixa concentração, para determinação do conteúdo total de Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, P, Pb, Sr e Zn em bebidas energéticas utilizando espectrometria de e...

We compared zinc, copper and cadmium concentrations and the operationally defined geochemical partitioning of the three metals in sediments enriched with biofilm versus sediments without obvious biofilm present (reference) sampled from five locations within the Fraser River Delta, British Columbia, Canada. Two-way ANOVA's with site and biofilm (enriched or reference) as the two factors were app...

Computer circuit board scrap was first treated with one part concentrated nitric acid and two parts water at 70 degrees C for 1 h. This step dissolved the base metals, thereby liberating the chips from the boards. After solid-liquid separation, the chips, intermixed with some metallic flakes and tin oxide precipitate, were mechanically crushed to liberate the base and precious metals contained ...

OBJECTIVE The levels of 10 heavy metals (arsenic, bismuth, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc) in gray Portland cement (GPC), white Portland cement (WPC), gray MTA (GMTA), and white MTA (WMTA) were analyzed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). STUDY DESIGN One gram of each material was digested with 80 degrees C "aqua-regia" (7 ...

Spatial variations and mobility of mercury (Hg) Hg associations with other potentially toxic elements (PTEs) were studied in soil samples from Alaba, the largest e-waste recycling site Nigeria West Africa. Total concentration was determined surface various locations using cold vapour atomic absorption spectrometry (CVAAS) following microwave-assisted acid extraction, while sequential extraction...

Studying and understanding the complexity interactions of different factors influencing stream sediment quality is necessary for development successful water management strategies. This study aims to evaluate level contamination by potentially toxic elements (PTEs) (As, Co, Cr, Cu, Mn, Ni, Pb, V, Zn) sediments Nile River. During spring 2019, river were sampled at 23 sites along For each sample,...