Original scientific paper
Spectrophotometric determination of lead in the form of chlorocomplexes
Zdenka Skurić
; Škola narodnog zdravlja »Andrija Štampar« Medicinskog fakulteta Sveučilišta u Zagrebu
K. Weber
; Škola narodnog zdravlja »Andrija Štampar« Medicinskog fakulteta Sveučilišta u Zagrebu
Abstract
A modification of the spectrophotometric method for the determination of lead in solutions is presented. The complexes are prepared in 4.0 M NaCl aqueous solutions. The absorption curves of the complexes (PbCl3)Na and (PbCl4)Na2 in the ultraviolet spectral region are determined at different NaCl concentrations (Fig. 1). It is believed that 4.0 M NaCl solution produces only the (PbCl4)Na2 complex. The analytical regression line for this complex - the absorbance (E) as the function of the lead concentration (c) - is determined at the wavelength of 268 nm which corresponds to the maximum of the absorption band (Fig. 3). The equation of this line (1) is put forward. Evidence has been obtained that NaCl may satisfactorily replace HCl in the development of the complexes (Fig. 2). The analytical procedure described is applied in the determination of atmospheric lead oxide within a wide concentration range. The results are compared with those obtained with the atomic absorption method (Table 2). The analysis of the effect of foreign cations and anions on the results obtained by the method described (Tables 3 and 4) has shown that this analytical procedure cannot be performed in the presence of Cu++ or Fe+++. A large number of other ions, Fe++ included, do not interfere with the analysis. A method for the determination of lead in biological material is in preparation.
Keywords
Hrčak ID:
167980
URI
Publication date:
25.6.1974.
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