Elsevier

Autor: Borges, Aline Rocha, Becker, Emilene M., Lequeux, Céline, Vale, Maria Goreti R., Ferreira, Sergio Luis Costa, Welz, Bernhard
Jazyk: portugalština
Rok vydání: 2011
Předmět:
Zdroj: Repositório Institucional da UFBA
Universidade Federal da Bahia (UFBA)
instacron:UFBA
DOI: 10.1016/j.sab.2011.04.004
Popis: Acesso restrito. Texto completo disponível no PORTAL de PERIÓDICOS da CAPES. p. 529-535. Submitted by JURANDI DE SOUZA SILVA (jssufba@hotmail.com) on 2012-01-30T16:14:57Z No. of bitstreams: 1 C__Documents and Settings_rep...t.default_Cache_2_09_B7AD5d01.pdf: 166059 bytes, checksum: edfd1817a0e8cb830a054f6d83342bd6 (MD5) Made available in DSpace on 2012-01-30T16:14:58Z (GMT). No. of bitstreams: 1 C__Documents and Settings_rep...t.default_Cache_2_09_B7AD5d01.pdf: 166059 bytes, checksum: edfd1817a0e8cb830a054f6d83342bd6 (MD5) Previous issue date: 2011-04 The determination of cadmium (Cd) in fertilizers is of major interest, as this element can cause growth problems in plants, and also affect animals and humans. High-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) with charge-coupled device (CCD) array detection overcomes several of the limitations encounteredwith conventional line source AAS, especially the problem of accurate background measurement and correction. In this work an analytical method has been developed to determine Cd in fertilizer samples by HR-CS GF AAS using slurry sampling. Both a mixture of 10 μg Pd+6 μg Mg in solution and 400 μg of iridium as permanent modifier have been investigated and aqueous standards were used for calibration. Pyrolysis and atomization temperatures were 600 °C and 1600 °C for the Pd-Mg modifier, and 500 °C and 1600 °C for Ir, respectively. The results obtained for Cd in the certified referencematerial NIST SRM695 (Trace Elements in Multi-Nutrient Fertilizer) of 16.7±1.3 μg g−1 and 16.4±0.75 μg g−1 for the Pd–Mg and Ir modifier, respectively, were statistically not different from the certified value of 16.9±0.2 μg g−1 on a 95% confidence level; however, the results obtained with the Ir modifier were significantly lower than those for the Pd–Mg modifier for most of the samples. The characteristic mass was 1.0 pg for the Pd–Mg modifier and 1.1 pg Cd for the Ir modifier, and the correlation coefficients (R2) of the calibration wereN0.99. The instrumental limits of detection were 7.5 and 7.9 ng g−1, and the limits of quantification were 25 and 27 ng g−1 for Pd–Mg and Ir, respectively, based on a sample mass of 5 mg. The cadmium concentration in the investigated samples was between 0.07 and 5.5 μg g−1 Cd, and hence below the maximum value of 20 μg g−1 Cd permitted by Brazilian legislation.
Databáze: OpenAIRE