Nischkauer Winfried, Izmer Andrei, Neouze Marie-Alexandra, Vanhaecke Frank, Limbeck Andreas
1 Institute of Chemical Technologies and Analytics, TU Wien, Vienna, Austria.
2 Department of Analytical Chemistry, Ghent University, Ghent, Belgium.
Appl Spectrosc. 2017 Jul;71(7):1613-1620. doi: 10.1177/0003702817693240. Epub 2017 Jan 1.
A combination of analyte pre-concentration using dispersed particle extraction (DPE) and dried-droplet laser ablation inductively coupled mass spectrometry (LA-ICP-MS) was developed with the aim to quantify Pt and Pd in urban particulate matter with an aerodynamic diameter ≤2.5 µm (PM). The PM aerosol was collected on cellulose ester filters during a sampling period of three days, with sampling intervals of 4 h only. Each of the filters was chemically digested, and the resulting solution was pre-concentrated using DPE. Droplets taken from the pre-concentrated sample were deposited on polymeric disks and dried. These dry spots were then analyzed by means of LA-ICP-MS. This approach allowed ICP-MS analysis of solutions with high content of dissolved sorbent particles coming from the DPE procedure. Furthermore, spectral interferences arising from sample-inherent matrix elements as well as solvent-related interferences could be removed by the proposed approach. The method was validated by determining the Pt concentration in Bureau Communautaire de Référence certified reference material (BCR CRM) 723 road dust certified reference material and a good agreement with the certified value was obtained. The temporal variation of Pt during the three-day sampling period is discussed, with respect to automotive traffic. The daily average of Pt measured in the air corresponds to typical values observed in urban areas in Central Europe. Although the pre-concentration of palladium is feasible with dispersed particle extraction, the method detection limits achieved here did not allow to quantify this element in the CRM or in the PM samples. The source for these high method detection limits for palladium are blank values arising from the filter material as well as the digestion procedure of the PM samples. Instrumental sensitivity of the approach would, however, suggest that palladium quantification is possible, provided the abovementioned blank issues are controlled better.
采用分散颗粒萃取（DPE）和干滴激光烧蚀电感耦合质谱（LA-ICP-MS）相结合的方法，旨在定量分析空气动力学直径≤2.5μm的城市颗粒物（PM）中的铂（Pt）和钯（Pd）。在三天的采样期内，以仅4小时的采样间隔，将PM气溶胶收集在纤维素酯滤膜上。每个滤膜进行化学消解，所得溶液用DPE进行预浓缩。从预浓缩样品中取出的液滴沉积在聚合物圆盘上并干燥。然后通过LA-ICP-MS分析这些干斑。这种方法允许对来自DPE程序的含有高含量溶解吸附剂颗粒的溶液进行ICP-MS分析。此外，所提出的方法可以消除样品固有基体元素产生的光谱干扰以及与溶剂相关的干扰。通过测定欧盟标准物质与测量研究院（BCR）认证参考物质723道路灰尘认证参考物质中的Pt浓度对该方法进行了验证，并获得了与认证值的良好一致性。讨论了三天采样期内Pt相对于汽车交通的时间变化。空气中Pt的日平均值与中欧城市地区观察到的典型值相对应。虽然用分散颗粒萃取对钯进行预浓缩是可行的，但这里实现的方法检测限不允许在CRM或PM样品中对该元素进行定量。钯的这些高方法检测限的来源是滤膜材料以及PM样品消解过程产生的空白值。然而，该方法的仪器灵敏度表明，只要能更好地控制上述空白问题，就有可能对钯进行定量分析。
