Determination of Isotopic Ratios and Metal Concentrations in Nicotiana tabacum (Tobacco)

ABSTRACT

Isotopic (δD, δ¹³C, and δ¹⁸O) and metal concentrations are reported for leaves, nervure, stems, and roots of N. tabacum grown in three parcels differentiated by the isotopic composition of irrigated water (deuterium enriched water, tap water, and deuterium depleted water). A linear correlation was observed between isotopic values (δD and δ¹⁸O) of water extracted from nervures and leaves with the isotopic composition of the irrigation water. The ¹³C-depletion in leaves was observed for all three groups in roots and stems. For the evaluation of heavy metals in N. tabacum, transfer factor values were determined. The highest values of the cadmium transfer factor, between 12.83 and 14.11 for nervure and leaves, were obtained for plants irrigated with enriched deuterium water. Also, transfer factors exceeding one were obtained for zinc in stems, nervure, and leaves from the first group. The correlations between heavy metals were made by using Pearson correlation. From cluster analysis, three groups were obtained that were differentiated by arsenic, lead, and iron concentration from every tissue. Principal component analysis demonstrated the presence of three components with a cumulative variance of 87.426%.

KEYWORDS:

• ICP-MS
• inductively coupled plasma-mass spectrometry
• IRMS
• isotope ratio mass spectrometry
• N. tabacum