A simple approach for the determination of heavy metals in airborne particulate matter (PM10) by Laser Ablation-Inductively Coupled Plasma Mass Spectrometry

The coupling of Laser Ablation (LA) with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is applied for the qualitative and quantitative determination of element in many areas of analytical chemistry (Di Franco et al., 2011; Giannossa et al., 2015). The aim of this work is the development of a method for the determination of heavy metals suspended by LA-ICP-MS in airborne inhalable particulate matter, sampled with an impactor high volume air sampler on quartz fiber filters. The easy, rapid, non-destructive method is proposed as a rapid screening procedure for this peculiar environmental specimen. The un-necessity of a preparative/extracting or diluting step and the absence of the stressing conditions generally included in that step (temperature, microwave power, strong acids) dramatically reduces the probability of interferences or underestimating errors (Rauch et al., 2001; Wang et al., 1999). On the other hand, a major statistical study is needed in planning instrumental conditions and data collecting, in order to ensure valuable and reproducible numerical data. We propose a cross-calibration procedure which uses the results obtained on some of the specimens of the sample batch, analysed after acidic digestion and interpolated on a aqueous standard solution calibration curve, as reference points for the direct quantification of the remaining samples, analysed under laser ablation. Real samples from a traffic city site and a rural site, taken as blank, were analysed and compared with acidic digestion analysis. The method was proved to be affordable, reliable and rapid to set. The method is also low environmental impact as it does not involve the use of harmful chemicals