应用氢化物发生-微波等离子体原子发射光谱分析食用菌中总砷含量

建立氢化物发生-微波等离子体原子发射光谱（microwave plasma-atomic emission spectroscopy，MP-AES）测定食用菌中总砷含量的分析方法。食用菌样品经湿法消解后采用预还原混合溶液（50 g/L硫脲＋10 g/L碘化钾）将砷（V）还原砷（III），采用多模式样品导入系统将砷（III）转变为气态三氢化砷，采用MP-AES进行测定。选择As 188.979 nm为MP-AES的分析谱线避开光谱重叠干扰，应用快速线性干扰校正模型校正背景干扰。砷的检出限为0.93 μg/L，不同种类食用菌中总砷含量在0.087～0.482 mg/kg之间。分析方法用于国家标准参考物质GBW10022（蒜粉）中的总砷分析，测定结果与GBW10022（蒜粉）的认定值一致，验证本实验的准确性。本实验为测定食用菌中总砷含量提供快速、准确、可靠的高通量分析方法。MP-AES使用氮气发生器从空气中产生的氮气为等离子体工作气，具有运行成本低的明显优势。

Total Arsenic Analysis in Edible Fungi with Hydride Generation-Microwave Plasma-Atomic Emission Spectroscopy

An analytical method for the determination of the total arsenic (As) concentration of edible fungi using hydride generation-microwave plasma-atomic emission spectroscopy (MP-AES) was established. After wet digestion of edible fungi samples, arsenic (V) was reduced to arsenic (III) using a pre-reducing solution (containing 50 g/L thiourea and 10 g/L potassium iodide). As (III) was transformed into gaseous arsenic trihydride using a multimode sample introduction system and detected by HG-MP-AES. The spectral line of As at 188.979 nm was selected as the analytical line to avoid spectral overlap interference. The background interference was corrected by using the fast linear interference correction model. The limit of detection for As was determined to be 0.93 μg/L. Total As levels of the different varieties of edible fungi samples tested ranged from 0.087 to 0.482 mg/kg. The results of this method for total arsenic in the standard reference material GBW10022 (garlic powder) were consistent with the certified value, indicating that this method is accurate. To sum up, MP-AES proved to be a fast, accurate and reliable high-throughput method for the determination of total arsenic in edible fungi samples. MP-AES used nitrogen generated from air with a nitrogen generator as the plasma working gas, reducing the cost.