This study describes the occurrence of a molecular interference affecting the determination of phosphorus by the molecular absorption of phosphorus monoxide (PO) at 213.647 nm using high-resolution continuum source graphite furnace molecular absorption spectrometry with direct solid sample analysis (HR CS SS-GF MAS). The study shows how the observation of the background signal provided by the software, which typically goes unnoticed as it is not well understood what is represented by it, provides valuable information for method development. In this case, the background signal hints at the formation of a concomitant polyatomic molecule in all solid samples investigated that is more volatile than PO and that can cause disturbances in the absorption of the target molecule. This information is paramount to properly optimize the temperature program. The most effective modifier to achieve quantitative PO molecule formation and better thermal stability consisted of a mixture of Au and Ca. The pyrolysis temperature was set at 1500 °C to minimize the influence of the interference mentioned above. The vaporization temperature was set at 2200 °C. Following this procedure, certified reference materials of leaf samples (NIST 1547, NIST 1570a, and NIST 1573a) could be accurately analyzed simply using external calibration with P aqueous solutions. Macauba and eucalyptus real samples were also analyzed, showing P concentrations of 455 ± 39 and 400 ± 35 μg g⁻¹, respectively. The limit of detection of the method was found to be 0.078 μg (n = 5), which translates into 78 μg g⁻¹ when using one mg of the sample, which seems appropriate for this type of sample.

中文翻译：

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使用高分辨率连续谱源石墨炉分子吸收光谱法和直接固体分析法了解通过PO分子测定磷中的多原子干扰

这项研究描述了使用高分辨率连续谱源石墨炉分子吸收光谱法和直接固体样品分析法通过213.647 nm处一氧化磷（PO）的分子吸收来影响磷测定的分子干扰的发生（HR CS SS-GF MAS ）。这项研究表明，对软件提供的背景信号的观察通常不会引起注意，因为人们对它所代表的含义不太了解，从而为方法开发提供了有价值的信息。在这种情况下，背景信号暗示了在所有研究的固体样品中伴随有多原子分子的形成，该多原子分子的挥发性比PO高，并且可能引起目标分子吸收的干扰。此信息对于正确优化温度程序至关重要。实现定量PO分子形成和更好的热稳定性的最有效的改性剂是Au和Ca的混合物。将热解温度设置为1500°C，以最大程度地减少上述干扰的影响。汽化温度设定为2200℃。按照此步骤，只需使用P水溶液进行外部校准，就可以准确地分析叶子样品的认证参考材料（NIST 1547，NIST 1570a和NIST 1573a）。还对Macauba和桉树真实样品进行了分析，显示P浓度为455±39和400±35μgg 汽化温度设定为2200℃。按照此步骤，只需使用P水溶液进行外部校准，就可以准确地分析叶子样品的认证参考材料（NIST 1547，NIST 1570a和NIST 1573a）。还对Macauba和桉树真实样品进行了分析，显示P浓度为455±39和400±35μgg 汽化温度设定为2200℃。按照此步骤，只需使用P水溶液进行外部校准，即可准确分析经过认证的叶子样品的参考材料（NIST 1547，NIST 1570a和NIST 1573a）。还对Macauba和桉树真实样品进行了分析，显示P浓度为455±39和400±35μgg^-1。发现该方法的检出限为0.078μg（ n = 5），当使用1 mg样品时，转化为78μgg ^-1，这似乎适用于此类样品。