微波消解结合ICP-OES和ICP-MS测定奇亚籽中多种矿物质元素的含量

建立奇亚籽中K (钾)、Na (钠)、Ca (钙)、Mg (镁)、Fe (铁)、Mn (锰)、Zn (锌)、Cu (铜)、P (磷)、B (硼)、Pb (铅)、Cd (镉)、As (砷)、Cr (铬)、Al (铝)、Ni (镍)16种矿物质元素的方法。样品经微波消解,以电感耦合等离子发射光谱(ICP-OES)测定K、Na、Ca、Mg、Fe、Mn、Zn、Cu、P、B含量,电感耦合等离子质谱(ICP-MS)测定Pb、Cd、As、Cr、Al、Ni含量。结果表明,此方法的ICP-OES检出限范围在0.00850~0.10200 mg/L,定量限范围在0.0283~0.3400 mg/L;ICP-MS检出限范围在0.00471~0.11330 mg/L,定量限范围在0.0157~0.3777 mg/L。线性相关系数均为r＞0.999,加标回收率为90.4%~99.8%,相对标准偏差为0~4.1%。同时用国家标准物质大米(GBW10045(GSB-1))和小麦(GBW10011(GSB-2))评价了方法的准确性,测定结果在标准值范围内。奇亚籽中含有丰富的P、K、Ca、Mg,其中P含量最高,为6860 μg/g,Ca含量为4085 μg/g,K含量为2798 μg/g,Mg含量为2515 μg/g;Fe、Zn、Al、Mn、Cu、Na、B含量(由高到低)在5~100 μg/g。同时检测出重金属危害元素Pb、Cd、Cr、Ni,其中Pb含量符合食品安全国家标准GB 2762-2017的限量要求,未能检测出As。该方法污染小、简便、高效、准确度高,适用于奇亚籽等植物类样品中多种化学元素的测定。

Determination of Multiple Mineral Elements in Chia Seeds by Microwave Digestion Combined with ICP-OES and ICP-MS

To establish the determination method of 16 mineral elements(K,Na,Ca,Mg,Fe,Mn,Zn,Cu,P,B,Pb,Cd,As,Cr,Al,Ni),the samples were digested by microwave. The contents of K,Na,Ca,Mg,Fe,Mn,Zn,Cu,P and B were determined by ICP-OES and the contents of Pb,Cd,As,Cr,Al and Ni were determined by ICP-MS. The results showed that the detection limit of ICP-OES was 0.00850~0.10200 mg/L and the limit of quantitation was 0.0283~0.3400 mg/L. The detection limit of ICP-MS was 0.00471~0.11330 mg/L and the limit of quantitation was 0.0157~0.3777 mg/L. The linear correlation coefficients were r>0.999,the recovery rate was more than 90.4%~99.8%,and the relative standard deviation was 0~4.1%. The accuracy of the method was evaluated by the national standard materials rice(GBW10045(GSB-1)and wheat(GBW10011(GSB-2)and showed that it was within the standard value range. The results showed that there were abundant P,K,Ca and Mg in Chia seeds,among which the content of P was the highest,6860 μg/g,followed by Ca 4085 μg/g,K 2798 μg/g and Mg 2515 μg/g. And the contents of Fe,Zn,Al,Mn,Cu,Na and B(from high to low)of 5~100 μg/g. At the same time,the harmful elements Pb,Cd,Cr and Ni of heavy metals were detected. Among them,the content of Pb met the limit requirements of national food safety standard GB 2762-2017,and As could not be detected. The method was simple,convenient,efficient and accurate. It was suitable for the determination of many chemical elements in plant samples such as chia seeds.