Eichornia crassipes is an atypical plant in the various regions of the Caribbean’s Central America e South American Countries. This plant causes severe problems in the aquatic environment of these places. Thus, it is necessary to remove this plant from the aquatic ecosystem causing immense environmental benefit. One alternative is transforming this plant into a solid low-cost phase for analytical methodologies and enabling cost reduction in the analysis of environmental pollutants. Toxic metal elements like lead have not function in the human body. It is crucial to determine lows concentrations of metals in water, foods, and beverages to assess daily consumption permissibility. Flame atomic absorption spectrometry (FAAS), compared to more sensitive equipment, is low-cost, easy-to-operate equipment, above all high precision and specificity. Their lack of sensitivity can be overcome with a preconcentration methodology. This work aims to transform the leaves of Eichornia crassipes into a new green solid-phase and find the best extraction conditions for Pb (II) determination by solid phase extraction (SPE) online with FAAS. The leaves of the plant were collected, washed with water, dried at room temperature, oven, milled, and sifted. The solid-phase extraction parameters, such as pH, type of eluent, sample flow rate, amount of sorbent, and eluent flow rate, were optimized. An experimental factorial design 2⁴ was applied with the sample flow, eluent flow, column mass, and volume of complexing agent. The two-dimensional central and rotating composite design was applied to the variables that obtained significance through experimental design. The elimination of a complexing agent allowed the methodology to become more compatible with the principles of green chemistry. The enrichment factor and the limit of detection were 48.5 and 2.35 $\mathrm{\mu }$g L⁻¹, respectively. The method was validated with SRM 1515 certified reference material. The SPE-FAAS online methodology with a minicolumn of Eichhornia crassipes is a simple, fast, economical, safe, and eco-friendly alternative for the determination of Pb(II).

凤眼莲是加勒比海中美洲和南美国家各个地区的非典型植物。这种植物在这些地方的水生环境中引起严重的问题。因此，有必要将其从水生生态系统中移出，从而带来巨大的环境效益。一种替代方法是将该工厂转变为低成本的固体分析方法阶段，并能够降低环境污染物分析的成本。诸如铅之类的有毒金属元素在人体中不起作用。确定水，食品和饮料中的低金属含量以评估每日消费许可至关重要。与更敏感的设备相比，火焰原子吸收光谱法（FAAS）是低成本，易于操作的设备，尤其是高精度和高特异性。他们的敏感性不足可以通过预浓缩方法来克服。这项工作旨在改变凤眼莲变成一种新的绿色固相，并通过FAAS在线通过固相萃取（SPE）找到用于测定Pb（II）的最佳萃取条件。收集植物的叶子，用水洗涤，在室温下干燥，烘箱，研磨并过筛。优化了固相萃取参数，例如pH，洗脱液类型，样品流速，吸附剂量和洗脱液流速。实验性析因设计2 ⁴将样品流量，洗脱液流量，色谱柱质量和络合剂体积应用于样品中。将二维中心旋转组合设计应用于通过实验设计获得意义的变量。消除络合剂使该方法与绿色化学原理更加兼容。富集因子和检出限分别为48.5和2.35$\mathrm{\mu }$g L ^-1。该方法已通过SRM 1515认证参考材料验证。SPE-FAAS在线方法与小柱凤眼莲是测定Pb（II）的简单，快速，经济，安全和环保的替代方法。