将秀珍菇样品用超纯水清洗后烘干至恒重,粉碎过0.149 mm筛。称取适量样品(约0.5 g),加入硝酸5 mL及过氧化氢1 mL进行微波消解。将溶液蒸至近干,残渣用硝酸(0.5+99.5)溶液溶解,并定容至25 mL。取上述4种元素的标准溶液制备标准曲线,采用高分辨连续光源和低噪声线阵电荷耦合式检测器,按选定的仪器工作条件进行钙、铁、镁、锌4种元素的火焰原子吸收光谱顺序测定。按所提出的方法用于实际样品分析,加标回收率在95.5%~104%之间,测定值的相对标准偏差(n=6)均小于3%。

Sample of Pleurotus geesteranus was washed with extrapure water and dried to constant weight. It was then crushed and pulverised to pass through sample sieve with bore diameter of 0.149 mm. An appropriate portion of the sample powdar (ca. 0.5 g) was taken and dissolved in 5 mL of HNO3 and 1 mL of H2O2 by microwave assisted digestion. The solution obtained was evaporated to near dryness and the residue was taken and made up to 25 mL with HNO3(0.5+99.5) solution. Standard curves were prepared with standard solutions of the 4 elements (i.e., Ca, Fe, Mg and Zn). The 4 elements in the sample solution were determined by FAAS under the optimized working condition of the instrument. By using high resolution continuous light source and lownoise linear array CCD, sequential determinations of the 4 elements were accomplished. The proposed method was used in the analysis of substantial sample giving values of recovery by standard addition method in the range of 95.5%-104% and values of RSD′s (n=6) less than 3%.