Accurate and Precise Zinc Isotope Ratio Measurements in Urban Aerosols

Autor(es)

Gioia, Simone ^[1] ; Weiss, Dominik ^{[2, 3]} ; Coles, Barry ^[2] ; Arnold, Tim ^[2] ; Babinski, Marly ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geociencias, Ctr Pesquisas Geocronol, BR-05508080 Sao Paulo - Brazil

^[2] Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, London SW7 2AZ - England

^[3] Nat Hist Museum, London SW7 5PB - England

• Tipo de documento: Artigo Científico
• Fonte: Analytical Chemistry; v. 80, n. 24, p. 9776-9780, DEC 15 2008.
• Citações Web of Science: 37

Resumo

We developed an analytical method and constrained procedural boundary conditions that enable accurate and precise Zn isotope ratio measurements in urban aerosols. We also demonstrate the potential of this new isotope system for air pollutant source tracing. The procedural blank is around 5 ng and significantly lower than published methods due to a tailored ion chromatographic separation. Accurate mass bias correction using external correction with Cu is limited to Zn sample content of approximately 50 ng due to the combined effect of blank contribution of Cu and Zn from the ion exchange procedure and the need to maintain a Cu/Zn ratio of approximately 1. Mass bias is corrected for by applying the common analyte internal standardization method approach. Comparison with other mass bias correction methods demonstrates the accuracy of the method. The average precision of delta(66)Zn determinations in aerosols is around 0.05% per atomic mass unit. The method was tested on aerosols collected in Sin Paulo City, Brazil. The measurements reveal significant variations in delta(66)Zn(Imperial) ranging between -0.96 and -0.37% in coarse and between -1.04 and 0.02% in fine particular matter. This variability suggests that Zn isotopic compositions distinguish atmospheric sources. The isotopic light signature suggests traffic as the main source. We present further delta(66)Zn(Imperial) data for the standard reference material NIST SRM 2783 (delta 66Z(Imperial) = 0.26 +/- 0.10%). (AU)

• Processo FAPESP: 06/59846-2 - Estudo da composição dos aerossóis e da assinatura isotópica de Pb, Cu e Zn como traçadores das fontes de poluição atmosférica na cidade de São Paulo e Cubatão
• Beneficiário: Simone Maria Costa Lima Gioia
• Modalidade de apoio: Bolsas no Exterior - Pesquisa