Abstract

The Moringa oleifera tree, including the leaves, flowers, pods, and seeds, is highly nutritious and useful for the prevention and control of various diseases. Here we have probed the micronutrients in Moringa oleifera leaves using laser-induced breakdown spectroscopy (LIBS). The time-resolved and time-integrated LIBS data reveal the presence of Ca, Mg, K, C, Si, Fe, Al, Ti, Sr, Na, H, O, and Li. The plasma temperature and electron number density required for the elemental composition analysis were estimated to be (6375 ± 500) K from the Saha-Boltzmann plot and (1.0 ± 0.2) $\times$ 10¹⁷ cm⁻³ from the Stark broadened H_α line, respectively. Elemental analysis of the samples was performed using one-line calibration free LIBS (CF-LIBS). The results reveal that C is the major element together with Ca, Mg, K, Fe Na, Al, Ti, Sr, and Li as micronutrients. The concentrations of the micronutrients determined by CF-LIBS were validated by inductively coupled plasma – optical emission spectrometry (ICP-OES). LIBS has been demonstrated to be a practical candidate for the detection of potentially toxic elements (Li, Al, Si, and Sr) as well as for the compositional analysis.

摘要

辣木树，包括叶子、花朵、豆荚和种子，营养丰富，可用于预防和控制各种疾病。在这里，我们使用激光诱导击穿光谱 (LIBS)探测了辣木叶中的微量营养素。时间分辨和时间积分的 LIBS 数据揭示了 Ca、Mg、K、C、Si、Fe、Al、Ti、Sr、Na、H、O 和 Li 的存在。根据 Saha-Boltzmann 曲线，估计元素组成分析所需的等离子体温度和电子数密度为 (6375 ± 500) K 和 (1.0 ± 0.2)$\times$距斯塔克加宽的 H _α线分别为10 ¹⁷  cm ^{-3 。}使用单线无校准 LIBS (CF-LIBS) 对样品进行元素分析。结果表明，C 是主要元素，Ca、Mg、K、Fe Na、Al、Ti、Sr 和 Li 作为微量元素。CF-LIBS 测定的微量营养素浓度通过电感耦合等离子体-光学发射光谱法 (ICP-OES) 进行验证。LIBS 已被证明是检测潜在有毒元素（Li、Al、Si 和 Sr）以及成分分析的实用候选者。