Elemental composition of PM can be determined by means of various spectroscopic techniques such as Atomic Absorption Spectrometry (AAS), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Laser-Induced Breakdown Spectroscopy (LIBS), Neutron Activation Analysis (NAA), Particle-Induced X-ray Emission (PIXE), X-Ray Fluorescence (XRF). The first two are the most used and standardized techniques for PM characterization . AAS is a technique that measures the absorption of specific wavelengths of light by atoms in the gaseous state. It is widely used for the determination of specific elements in PM . AAS can be performed using flame, graphite furnace, or hydride generation systems, depending on the elements of interest and their concentrations. ICP-MS is a highly sensitive technique that combines inductively coupled plasma as the excitation source with mass spectrometry for the determination of element based on their mass to charge ratios. It allows for simultaneous analysis of a wide range of elements, with detection limits at the level of ng L -1 . ICP-MS offers excellent sensitivity, precision, and accuracy, making it suitable for elemental analysis of PM in various environmental and biological samples. LIBS is a technique that utilizes a laser pulse to generate a plasma confined in the volume containing PM both in the solid and the gas phase, making it suitable for online measurements. Following the emission of light in LIBS, the subsequent step involves analysing the emitted light using optical spectrometry to determine the elemental composition . LIBS offers rapid analysis, requires minimal sample preparation, and can be combined with machine learning and chemometrics method for PM source apportionment . NAA is another technique employed for PM characterization. It involves bombarding the sample with neutrons to induce radioactive isotopes. The emitted gamma rays from these isotopes are measured and used to determine the elemental composition. NAA provides high sensitivity and can analyse a wide range of elements, including trace elements (detection limits ranging from 0.1 to 1x10 6 ng g -1 ) PIXE employs ion beams to induce X-ray emissions from the sample, enabling the identification and quantification of its constituent elements. Qualitative and quantitative analysis provide crucial data regarding the chemical composition of PM . PIXE employs a range of ions to induce X-ray emissions, and the selection of the appropriate ion based on the unique demands of the analysis. Protons (H + ), helium ions (He + or α-particles), and their use are predominant in PIXE due to their versatility and wide applicability . Alternative ions like heavy ions (e.g., carbon, oxygen, argon) or secondary ions (e.g., Li+, Be+) may be harnessed, albeit less commonly. The choice of these ions is to meet specific factors such as the elements under investigation, the composition of the sample, and the desired depth of analytical penetration. XRF is a non-destructive analytical technique that measures the fluorescent X-rays emitted when a sample is irradiated with X-rays. By detecting and analysing these emitted X-rays, XRF provides multi element information of PM composition. It is widely used for both qualitative and quantitative analysis of PM, determining major and trace elements. The accessibility, low maintenance costs, and versatility of XRF laboratory and portable instrumentation combined with possibility of in situ analysis make it an attractive option for a wide range of application like geological exploration, environmental monitoring, and archaeology. XRF is considered a green analytical technique because it typically requires fewer chemicals and generates less waste compared to the other wet chemical methods. Furthermore, XRF instrumentation and operation are cost-effective with respect to other analytical techniques.