Sequential and Simultaneous Determination of Cd, Fe and Ni in Toothpastes Employing Slurry Sampling High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry

• Published in: Analytical letters Vol. 55; no. 8; pp. 1192 - 1206
• Main Authors: Silva, Arlene Santos, Brandão, Geovani Cardoso, Ferreira, Sergio Luis Costa, dos Santos, Ana Maria Pinto
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 24.05.2022; Taylor & Francis Ltd
• Subjects: Absorption spectroscopy; Atomic absorption analysis; Atomizing; Cadmium; High resolution; high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS); Iron; multielemental determination; Nickel; Palladium; Pyrolysis; Response functions; Sampling; Scientific imaging; Slurries; slurry sample; Spectrometry; Toothpaste
• ISSN: 0003-2719; 1532-236X
• DOI: 10.1080/00032719.2021.1991941

Here is reported an analytical method for the multielemental determination of Cd, Fe and Ni in toothpaste employing slurry sampling high-resolution continuum source electrothermal atomic absorption spectrometry (HR-CS ET AAS). Using a single sample aliquot, Cd was determined at 228.802 nm, and, sequentially, Fe (232.036 nm) and Ni (232.003 nm) were simultaneously determined. Pyrolysis and atomization temperatures were 800 and 1500 °C for Cd, respectively. An atomization temperature of 2600 °C was used for Fe and Ni. A Pd and Mg mixture was used as the chemical modifier for standards and samples. The procedure for the slurry preparation was optimized using multivariate methodology with a multiple response function while employing a sample mass of about 250 mg. The optimized conditions were: 0.8 mol L −1 HNO 3 , 0.5% (m/v) Triton X-100 and a sonication time of 15 min. Using aqueous standards for the calibration, limits of detection and quantification were of 3.2 and 10.8 ng g −1 for Cd, 2.2 and 7.4 µg g −1 for Fe, and 0.044 and 0.148 µg g −1 for Ni. The precision estimated as relative standard deviation (n = 5) was 6.1% for Cd, 3.5% for Fe and 4.4% for Ni. The method accuracy was evaluated by standard addition and recovery tests and the recoveries varied from 93 to 114%. The method was applied for the analysis of five toothpaste samples of different brands. The concentrations ranged from 52.0 to 73.6 µg g −1 for Fe, and < 0.148 to 0.227 µg g −1 for Ni. For Cd, the concentrations were below the limit of detection.