食用蓝藻螺旋藻和葛仙米中金属元素的分析

采用硝酸和高氯酸(4∶1)混合酸消化2种可食用蓝藻螺旋藻和葛仙米,原子吸收光谱法检测螺旋藻和葛仙米中的K、Na、Mg、Ca、Zn、Fe、Cu、Mn、Cr、Pb和Cd共11种金属元素含量。结果表明,2种蓝藻中矿质元素含量均较高,特别是Ca含量高达61 905.132mg·kg~(-1);而有害重金属Cr,Po和Cd含量均远低于国家规定标准,表明这2种食用蓝藻均无重金属富集或污染。本结果显示,螺旋藻和葛仙米是极好的天然富钙营养食品,可作为人体矿质元素和微量元素缺乏症的补给品.

Content determination of the Metal Elements in the Edible Algae Spirulinaand Nostoc sphaeroides

The dry powder from two kinds of edible cyanobacteria Spirulinaand Nostoc sphaeroides were first digested by using nitric acid and perchloric acid(4∶1)mixed acid and then the contents of K,Na,Mg,Ca,Zn,Fe,Cu,Mn,Cr,Pb,Cd in Spirulinaand Nostoc sphaeroides were determined by using flame atomic absorption spectrometry.The results showed that the mineral element contents in the two kinds of cyanobacteria were abundant,for example,Ca content in Spirulina was as high as 61 905.132 mg kg~(-1).However,heavy metal element contents in Spirulinaand Nostoc sphaeroides were far below the national standard stipulated by the government of China,indicating that no enrichment of heavy metal or pollution occurs in them.Our results also suggest that Spirulinaand Nostoc sphaeroides can be excellent nutrition foods of natural rich calcium and can be used as an effective tonic of human who is in the deficiency of mineral elements and trace elements.This study may be helpful for evaluating of the edible and medicinal values of Spirulinaand Nostoc sphaeroides.