Resumen

BELLATO, Ana Cláudia S.; MENEGARIO, Amauri A.  y  GINE, Maria Fernanda. Boron isotope dilution in cellular fractions of coffee leaves Evaluated by Inductively Coupled Plasma Mass Spectrometry with direct injection nebulization (DIN-ICP-MS). J. Braz. Chem. Soc. [online]. 2003, vol.14, n.2, pp. 269-273. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532003000200014.

Enriched ¹⁰B (94.14 atom %) was supplied to coffee plantlets for three months. Then boron isotope ratios were determined in the leaf cell compartments, cell wall, nuclei and chloroplast, after a sub-cellular fractionation procedure. The isotopic measurements were performed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) provided with a direct injection nebulizer (DIN), introducing a sample volume of 50 mL. Isotopic ratios from 1.002 to 1.326 were determined with precision characterized by RSD lower than 1.5% for the enriched cell fractions with B concentrations ranging from 3.3 to 10.8 mg g^-1. The detection limit (3s) was 0.5 ng B mL^-1. The average enrichments in ¹⁰B atom % found in the cell walls, nuclei and chloroplasts were 46.7, 44.5 and 48.8, respectively.

Palabras llave : isotope dilution; inductively coupled plasma mass spectrometry; biological cell fractionation; boron isotope ratios; plant analysis.