Analysis of organic micropollutants and other molecules

Organic micropollutants, although present at trace concentrations, pose significant environmental and human health risks. Their monitoring is crucial, as these substances—including pesticides, pharmaceuticals, and endocrine disruptors—can persist in the environment and bioaccumulate in living organisms. Their presence in water, soil, and air can disrupt ecosystems, impact biodiversity, and induce long-term toxic effects, even at low concentrations. Furthermore, organic micropollutants may enter the food chain, posing risks such as chronic diseases and hormonal imbalances. Regular monitoring helps identify pollution sources, assess the effectiveness of emission reduction strategies, and ensure the protection of ecosystems and public health. It also provides a crucial foundation for scientific research aimed at understanding their dispersion mechanisms, impacts, and the development of effective remediation technologies.

GC-MS System

Gas chromatography coupled with mass spectrometry (GC-MS) is a powerful analytical technique for the separation, identification, and quantification of compounds in a sample. In GC, compounds are vaporised and injected into an inert gas stream, which transports them through a separation column. Separation occurs based on each compound’s affinity for the column’s stationary phase. The separated compounds then enter the MS, where they are ionised and fragmented. The masses and abundances of the resulting ions are recorded, generating a unique mass spectrum for each compound, allowing precise identification.

HPLC-MS/MS System

High-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) is an advanced analytical technique for the separation, identification, and quantification of chemical compounds. In this method, samples are first separated via HPLC, where they are dissolved in a mobile phase and passed through a column containing a stationary phase. The separated compounds are then ionised and introduced into the mass spectrometer, where precursor ions are generated. These ions undergo a second fragmentation stage within the mass analyser, producing fragment ions that allow precise identification. HPLC-MS/MS combines high-resolution chromatographic separation with the sensitivity and specificity of mass spectrometric detection.

The study and chemical characterisation of microplastics are essential to understanding their environmental and health impacts. These ubiquitous particles, found in both marine and terrestrial environments, can adsorb chemical pollutants, increasing their toxicity. Chemical characterisation enables the identification of polymers and additives, facilitating the assessment of their persistence and degradation in the environment. Furthermore, understanding microplastic interactions with living organisms is crucial for evaluating ecotoxicological risks.

Chemical Characterisation of Microplastics via Pyrolysis-GC-MS (Py-GC-MS)

Microplastic analysis via pyrolysis-GC-MS (gas chromatography coupled with mass spectrometry) involves the thermal decomposition of samples under anoxic conditions to produce volatile fragments. These fragments are then separated by gas chromatography. The separated compounds are detected and identified using mass spectrometry, allowing for the precise characterisation of polymers present in microplastics. This technique is particularly effective for qualitative and quantitative identification of microplastics in various environments, offering high sensitivity and specificity for distinguishing different degraded plastics. 

By adjusting pyrolysis temperatures, this method also allows for the potential identification of additives (e.g., UV stabilisers, hardening agents) present in plastics via thermal desorption.