Determinação voltamétrica de metais em águas e fluidos biológicos empregando mineralização de amostras com radiação ultravioleta

Abstract

#Este artigo é dedicado ao Sr. Antônio Augusto Bolli pelos seus 80 anos de vida, criatividade, inventividade e dedicação ao trabalho. This work describes the optimization of pretreatment steps for the destruction of organic matter in samples of waters and biological fluids, by using an UV irradiation system with a high power UV radiation source (400 W). The efficiency of the system constructed for the photo-decomposition of samples of model waters, natural waters and biological fluids was investigated by performing recovery experiments of the metallic species Zn(II), Cd(II), Pb(II), Cu(II), Al(III) and Fe(III). The use of UV irradiation allowed the liberation of metals bound to the organic matrix and the determination of the total content of elements in the samples.

Determination of metallic contaminants in human recombinant erythropoietin (EPO) formulations by adsorptive cathodic stripping voltammetry and UV photo-decomposition of samples

“…16 In order to investigate the influence of this parameter, we submitted the spiked EPO samples to the UV irradiation process in a home-made UV digestor, which contained a high-pressure mercuy lamp of 400 W routinely used for public illumination. 15 As it can be seen in Table 3, lower recovey values (85-96%) were obtained for Al, Cr and Ni in spiked EPO samples irradiated under the optimized conditions (Table 2) by using a 400 W radiation source. The results in Table 3 show that the Hg lamp power influences the decomposition efficiency of diluted EPO samples.…”

“…13,14 However, in complex matrices, such as EPO formulations, metallic species are normally bound to the organic components of the matrix. 15 The UV irradiation for the photo-decomposition of samples is often employed in combination with the voltammetric determination of metals. Since the method normally uses small amounts of reagents (few mL of acids and H 2 O 2 ) for the photodecomposition, it eliminates the matrix interference without contaminating the sample before the analysis.…”

“…Comparative UV photo-decomposition experiments were performed in a home-made UV digestor with a high-pressure mercury lamp of 400 W used for public illumination, as described elsewhere. 15 All UV photodecomposition experiments were performed at 85 ± 3 °C. …”

“…Similar results have already been obtained in the photo-decomposition of undiluted urine samples by using the same home-made UV irradiation system described elsewhere. 15 …”

Analytical chemistry in Brazil: healthy and growing

“…The authors demonstrated that using a high power ultraviolet radiation source (400 W) it was possible to liberate metals bound to the organic matrix for the determination of the total contents of elements in the samples. 19 Preliminary steps before sample digestion are also important. Santos et al 20 investigated the effects of grinding and sieving of bivalves, coffee and cowpea beans before multi-element analysis.…”