title: Simultaneous determination of Cd, Cu, Mn, Ni, Pb and Zn in nail samples by inductively coupled plasma mass spectrometry (ICP-MS) after tetramethylammonium hydroxide solubilization at room temperature: comparison with ETAAS.
abstract: A simple method is described for the determination of Cd, Cu, Mn, Ni, Pb and Zn in nails by using inductively coupled plasma mass spectrometry (ICP-MS) or electrothermal atomic absorption spectrometry (ETAAS). Prior to analysis, 10-20 mg of nail samples were accurately weighed into (15 mL) conical tubes. Then, 1 mL of 25% (w/v) tetramethylammonium hydroxide (TMAH) solution was added to the samples, incubated at room temperature overnight and then further diluted to 10 mL with 1% (v/v) HNO(3). After that, samples were directly analyzed. Rhodium was used as internal standard for ICP-MS analysis. Method detection limits (3 s, n=20) were 0.1, 3.0, 1.0, 4.5, 1.5, 5.0 ng g(-1) for Cd, Cu, Mn, Ni, Pb and Zn, respectively for ICP-MS, and 24, 26, 30, 143, 130 and 1000 ng g(-1), respectively for ETAAS. The key issue addressed here is the elimination of the acid digestion prior to analysis. Moreover, with the use of the proposed method there is a considerable improvement in the sample throughput comparing to the traditional methods using microwave-assisted acid sample digestion prior to analysis. For validation purposes, six ordinary nail samples were solubilized and then directly analyzed by ICP-MS and ETAAS, with no statistical difference between the two techniques at 95% level on applying the t-test.
authors.affiliation: Laboratório de Toxicologia e Essencialidade de Metais, Depto. de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto-USP, Avenida do Café s/n, Monte Alegre 14040-903, Ribeirão Preto-SP, Brazil.
authors.forename: Bruno L
authors.initials: BL
authors.lastname: Batista
authors.forename: Jairo L
authors.initials: JL
authors.lastname: Rodrigues
authors.forename: Juliana A
authors.initials: JA
authors.lastname: Nunes
authors.forename: Luciano
authors.initials: L
authors.lastname: Tormen
authors.forename: Adilson J
authors.initials: AJ
authors.lastname: Curtius
authors.forename: Fernando
authors.initials: F
authors.lastname: Barbosa
mesh_terms: D002104:Cadmium; D003300:Copper; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D007854:Lead; D008345:Manganese; D013058:Mass Spectrometry; D019216:Metals, Heavy / Q000032:analysis*; D009262:Nails / Q000737:chemistry*; D009532:Nickel; D013054:Spectrophotometry, Atomic / Q000379:methods* / Q000592:standards; D015032:Zinc
chemical_list: D019216:Metals, Heavy; D002104:Cadmium; D007854:Lead; D008345:Manganese; D003300:Copper; D009532:Nickel; D015032:Zinc