This research investigated the current methods of characterization of ions and metals in particulate matter pollutants from different emission sources. The study was conducted through the Proknow-C methodology, in which a portfolio that includes scientific and review articles was selected. The document addresses different methodologies currently used to quantify diverse ions and metals (IIMM) found in particulate matter (PM), specifically focused on PM₁₀ and PM_2.5. The investigation was made going through the types of filters used to capture the pollutant, the equipment and the corresponding characterization techniques. Results show the Proknow-C method is a reliable way to analyze PM pollution research, revealing the state of art for metals and ions types, characterization technologies, current situations and trends. Sulfate, nitrate, and ammonium ions are found in concentrations between 70 and 80% of the PM. Among the main metals found are chromium, nickel, lead, cadmium, iron, manganese, coper, and zinc. The main detection method found in the studied research was inductively coupled plasma mass spectrometry. It was also found that geographic information systems are a good tool for integrating special data with PM and air pollution, which could accelerate the diagnosis and thus the actions to give solution to the problem.

The carbonaceous particles represent a significant fraction in the particulate matter (PM) and are considered an environmental hazard due to their effects on climate and health. The main goal in this research is to identify and analyze the scope that have been achieved so far on the characterization and measurement of the carbonaceous fraction present in PM, a great contribution to global pollution and thus to the deterioration of public health. The ProKnow-C methodology was used to build a bibliographic portfolio and perform a bibliometric and systemic analysis of the information found in the chosen databases. The contribution of these carbonaceous compounds to PM is very significant, reaching values up to 50%. The most used methods for the determination of organic and elemental carbon are thermo-optical reflectance and transmittance. Positive Factorization models are used worldwide to determine potential sources of particulate matter emissions. Even though various studies have been developed to understand these carbonaceous substances, there are several limitations in the measurements and limited knowledge on the subject. The positive outcomes and future possibilities were analyzed as well.

Particulate matter (PM), particle pollution that can travel long distances, is a big concern because it contains liquid droplets or microscopic solids resulting in significant health issues such as respirational and cancer problems. Therefore, the characterization of these particles is very significant as a hazard to public health. PM can be identified by X-ray diffraction (XRD) and Raman spectroscopy (RS), both powerful and non-destructive technologies. RS, in particular, allows the identification of black carbon, considered one of the pollutants with the greatest influence on climate change. Another important technology for the evaluation of inorganic and organic functional groups present in PM compounds is the Fourier transform infrared spectroscopy (FTIR). X-ray fluorescence (XRF) provides elemental analysis, revealing, in many cases, the original source of the sample. In order to understand the current state of the art, the Proknow-C method was applied to track the most recent information on PM characterization. Aspects such as sample collection, filter material, characterization parameters, PM components, and the advantages and limitations of each technique are discussed. PM minerals are found to be composed of silicates, oxides, sulfates, and carbonates. The elemental components of PM are classified into five categories: marine aerosol, mineral material, anthropogenic elements, organic carbon, and elemental carbon. The XRD technique is a powerful, fast, and non-destructive tool to identify various minerals present in PM. On the other hand, the XRF technique requires minimal sample treatment, but its sensitivity is limited for the determination of trace metals and some relevant environmental elements. FTIR spectroscopy is able to identify and quantify all organic functional groups present in atmospheric PM. Despite its advantages, a proper choice of calibration method is crucial to ensure its effectiveness. RS is fast and simple, although it only detects Raman-active functional groups. These are some of the advantages and limitations of these techniques addressed in the following review article.

Medellín, a densely populated city in the Colombian Andes, faces significant health and environmental risks due to poor air quality. This is linked to the atmospheric dynamics of the valley in which it is located (Aburrá Valley). The region is characterized by a narrow valley and one of the most polluted areas in South America. This is a comparative study of the chemical composition of PM_2.5 (particles with diameter less than 2.5 µm) in Medellín between two periods (2014–2015 and 2018–2019) in which temporal trends and emission sources were evaluated. PM_2.5 samples were collected from urban, suburban, and rural stations following standardized protocols and compositional analyses of metals (ICP-MS), ions (ion chromatography), and carbonaceous species (organic carbon (OC) and elemental carbon (EC) by thermo-optical methods) were performed. The results show a reduction in average PM_2.5 concentrations for the two periods (from 26.74 µg/m³ to 20.10 µg/m³ in urban areas), although levels are still above WHO guidelines. Urban stations showed higher PM_2.5 levels, with predominance of carbonaceous aerosols (Total Carbon—TC = OC + EC = 35–50% of PM_2.5 mass) and secondary ions (sulfate > nitrate, 13–14% of PM_2.5 mass). Rural areas showed lower PM_2.5 concentrations but elevated OC/EC ratios, suggesting the influence of biomass burning as a major emission source. Metals were found to occupy fractions of less than 10% of the PM_2.5 mass; however, they included important toxic species associated with respiratory and cardiovascular risks. This study highlights progress in reducing PM_2.5 levels in the region, which has been impacted by local policies but emphasizes current and future challenges related mainly to secondary aerosol formation and carbonaceous aerosol emissions.

Plant leaves are natural receptors of atmospheric pollutants and have recently been used in the field of environmental biomonitoring due to their usefulness for large-scale measurements and low cost. Despite growing research in this area, the is no standardized methodology for the characterization of organic and inorganic compounds on the leaf surface, which hinders researchers in selecting appropriate techniques. This study aims to address this gap by answering the question: “What are the methodologies for the characterization and analysis of organic and inorganic compounds in the phyllosphere or on the leaf surface?” For this purpose, a systematic review was conducted to compile and compare the methodologies applied to characterize, observe, or analyze the particular matterial on the leaf surface, thereby facilitating informed methodological decisions in future environmental studies. To achieve this, a literature review was conducted for the period between 2014 and 2024 using the ProKnow-C methodology (Knowledge Development Process—Constructivist) in order to identify and characterize the methods employed for the analysis of compounds on the leaf surface. A total of 135 articles were analyzed, identifying China as the country with the highest number of publications and 2024 as the year with the greatest scientific production on the topic, demonstrating a significant growth in research interest in this field. The methods identified were grouped into five main categories, with gravimetric techniques being the most frequently used. The review highlights the lack of standardized methods in the reviewed studies, which hinders reproducibility and comparability. Through the compilation, a methodological reference was created that provides a basis for options in future studies, depending on the type of compound being analyzed and the specific research context, contributing to future efforts toward method standardization.