Preparation of ashless cellulose paper standards for rapid determination of multi-element concentrations in airborne fine particulate matter using laser ablation inductively coupled plasma mass spectrometry

Abstract

In this study, we developed ashless cellulose filter papers as calibration standards in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to rapidly determine multi-element concentrations in airborne fine particulate matter (PM_2.5). To achieve this, the papers were treated by immersion in standard solutions, followed by evaporation of the solutions. The homogeneity of the paper standards was studied, and the results demonstrated that the elements were homogeneously distributed at the paper centers with slight fluctuations (i.e., relative standard derivation ≦ 8%). The instrument signal drift and instability were compensated using a pseudo internal standard (¹⁹⁷Au). The limits of detection established for LA-ICP-MS were obtained by the ablation of 11 lines on the procedural blank filter paper containing 0.5% HNO₃, with values ranging from 0.01 (Sr) to 0.49 μg g⁻¹ (Fe). The accuracy of the LA-ICP-MS determinations was validated using certified reference materials (CRMs) and analyzed using six line scans. The results showed acceptable analytical errors (<13%). Thus, our method was applied to analyze actual PM_2.5 samples. Moreover, the sources of PM_2.5 in Hangzhou were also investigated. Additionally, this method has considerable potential for multi-element analysis in other airborne dusts.