Abstract A flow injection photochemical vapor generation atomic absorption spectrometry (FI-PVG-AAS) system was developed for selenium determination. The variables of influence of the photochemical generation process were evaluated and optimized. Sample already reduced to the Se(IV) state and mixed with the photochemical reagent (1.5% w/w HCOOH) was irradiated for 3 s. Selenium derivatives were transferred to an externally heated atomization cell by an argon-hydrogen mixture and selenium determined at 196.0 nm. Nitrogen was used as the carrier of the flow injection system. Nitrate is one of the most relevant interferents for the photochemical generation process; it is a very frequent concomitant as nitric acid is added for sample digestion or preservation. Hence, its removal before the vapor generation stage was studied. It was found that up to 3.0% w/w HNO3, it can be eliminated in the reduction stage of Se(VI) to Se(IV) with hydrochloric acid. For higher concentrations (up to 21% w/w HNO3), prior to the reduction step, the addition of 40% w/w H2CO and evaporation almost to dryness was successful for the abatement of the interference. The performance of the method was studied and its applicability evaluated with a Trace Element in Water Certified Reference Material (24.3 μg L−1 – Se, 2.8% w/w HNO3) and a spiked rice-flour microwave-assisted digest (103.1 μg L−1 – Se, 18.5% w/w HNO3).

中文翻译：

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减少硝酸盐对光化学蒸汽产生法测定硒的干扰

摘要 研制了流动注射光化学气相发生原子吸收光谱法（FI-PVG-AAS）系统，用于硒的测​​定。对光化学生成过程的影响变量进行了评估和优化。样品已还原为 Se(IV) 状态并与光化学试剂 (1.5% w/w HCOOH) 混合，然后照射 3 秒。通过在 196.0 nm 处测定的氩氢混合物和硒将硒衍生物转移到外部加热的雾化池中。氮气用作流动注射系统的载体。硝酸盐是光化学生成过程中最相关的干扰物之一；这是一种非常常见的伴随物，因为添加硝酸用于样品消解或保存。因此，研究了它在蒸汽发生阶段之前的去除。发现最多3个。0% w/w HNO3，可在 Se(VI) 还原为 Se(IV) 的阶段用盐酸消除。对于更高浓度（高达 21% w/w HNO3），在还原步骤之前，添加 40% w/w H2CO 并蒸发至几乎干燥可成功消除干扰。研究了该方法的性能并使用水中有证标准物质中的痕量元素（24.3 μg L-1 – Se，2.8% w/w HNO3）和加标米粉微波辅助消解物（103.1 μg L -1 – Se，18.5% w/w HNO3)。