No abstract

No abstract

Volatile species of Zn were generated by merging acidified aqueous samples and sodium tetrahydroborate(III) solution in a continuous flow system. The gaseous analyte was subsequently introduced via a stream of Ar carrier into the inlet tube of the plasma torch. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for detection. The operating conditions (chemical and physical parameters) and the concentrations of different inorganic (hydrochloric, nitric) and organic acids (acetic, citric, oxalic, tartaric) were evaluated for the efficient generation of Zn vapour. A detection limit (3sigma(blank)) of 4.6 ng mL(-1) was achieved. The precision (RSD) of the determination was 6.9% at a level of 250 ng mL(-1) and 4.7% for 1000 ng mL(-1) (n = 10). The efficiency of the generation process was estimated to be close to 50% in HCl. The possible interferent effect of transition metals (Cd, Co, Cu, Cr, Fe, Mn, Ni), hydride forming elements (As, Ge, Pb, Sb, Se) and Hg on Zn signal was examined. The method was validated by the determination of Zn in a certified reference material (CRM), NIST 1643d trace elements in water.

No abstract

No abstract

No abstract

A novel method has been developed to determine As-containing animal feed additives including roxarsone (ROX), p-arsanilic acid (p-ASA) and nitarsone (NIT), as well as other organic As species (dimethylarsonic acid (DMAA) and monomethylarsonic acid (MMAA)) by ion-pairing high-performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry (IP-HPLC-HG-AFS). A simple isocratic reversed-phase (RP) HPLC method with a mobile phase containing citric acid and sodium hexanesulfonate (pH 2.0) was developed using a C(18) column. The use of an organic solvent free mobile phase turns this methodology into an environmentally friendly alternative. Several ion pair forming agents, such as sodium hexanesulfonate, tetrabutylammonium bisulfate and perfluoroheptanoic acid, were studied. The limits of detection for As species were calculated in standard solution and resulted to be 0.2, 0.5, 0.6, 1.6, and 1.6 μg As L(-1) for MMAA, DMAA, p-ASA, ROX and NIT, respectively. This method exhibited convenient operation, high sensitivity and good repeatability. It was applied to As speciation in different samples including arugula, dog food, dog urine and chicken liver.

No abstract