Analysis of the content and speciation of aluminum in Enteromorpha prolifera

The method of continuous extraction and inductively coupled plasma emission spectroscopy (ICP-OES) was adopted. The raw material was Enteromorpha prolifera from Zhejiang coast. Based on the analysis of aluminum content in Enteromorpha prolifera from different sea areas, the distribution and existing forms of aluminum in E. prolifera were mainly investigated, and the extraction conditions were optimized.The optimized extraction parameters are as follows: E. prolifera was comminuted to 20-30 mesh, extracted for 60 min with 0.8 mol / L HCl solution at 60 °C, extracted for 60 min with 0.8 mol / L NaOH solution at 70 °C. The results showed that the total aluminum content of E. prolifera was as high as 1585.25-1776.48 mg/kg, mainly organic aluminum and active aluminum.Organic aluminum is mainly soluble polysaccharide-bound aluminum (Al_osu), small molecular protein aluminum (Al_pros), seaweed gel-bound aluminum (Al_swg), large molecular protein aluminum (Al_pro), and fibrous aluminum (Al_ofi), which account for 1.77%-2.70%, 12.65%-17.11%, 39.76%-42.08%, 20.31%-22.23%, and 11.99%-14.51% of the total aluminum, respectively. Active aluminum is mainly hydroxyl aluminum (Al(OH)²⁺, Al³⁺, etc.), AlF and soluble organic aluminum (Al_osm), accounting for 8.57%-11.38% of the total aluminum. The above experimental results can provide scientific basis for the evaluation of food safety and the establishment of aluminum limit standard of E. prolifera.