Elemental analysis of carrageenans isolated from Hypnea musciformis red algae of Karachi coast using SEM-EDX

The carrageenans with high molecular weight, crude and dialysed polysaccharide fractions obtained from Hypnea musciformis red algae of Karachi coast in Pakistan. The elemental composition was determined by using SEM-EDX technique which is one of the modern, reliable and accurate techniques. After analyzing multiple mineral elements were detected in different quantities. The numbers of elements found in crude extracts were greater than that in the dialysed extracts. All extracts contained the higher concentrations of C followed by O (except dialysed acidic extract). Among other elements, Cl and K were present in the highest amounts (>25.0%) in dialysed acidic extracts. However, Al was detected in low concentrations in only crude aqueous and acidic extracts. The mineral concentrations ranges were 30.34-52.46%, 17.00-43.46%, 0.63-4.05%, 0.49-3.35%, 0-0.33%, 0.74-17.92%, 0.59-25.31%, 0.58-25.46%, 1.10-6.72%, 0-2.60% for C, O, Na, Mg, Al, S, Cl, K, Ca and Zn in these crude and dialyzed extracts respectively. The study confirmed the presence of major elements such that Na, Mg, Ca, K and Zn in high quantities. However, there was no toxic element identified like Cd, Hg and Pb which show that these carrageenans are safer to utilize in food and pharmaceutical industries.