To achieve these objectives extensive analytical chemistry for the improved detection of carbon, in the form of nanoplastics, is required. More specifically, Inductively coupled plasma mass spectrometry (ICP-MS) was optimized for the sensitive and selective detection of carbon. This resulting a novel analytical technique which makes use of reversed phase (RP) high performance liquid chromatography (HPLC), operated with a 100% aqueous mobile phase, coupled to inductively coupled plasma – mass spectrometry (ICP-MS) for the determination of organic compounds via selective monitoring of 12C or 13C. This marks the first time that ICP-MS has been used with RP HPLC for carbon detection, thus opening up a new range of analytical capabilities for trace level organic compound detection. To demonstrate proof of principal, this new analytical technique was used for the determination of methanol and ethanol in alcoholic beverage samples diluted 1:100 and injected directly onto a reversed phase C18 column without any further sample preparation. The instrumental limit of detection (LOD) for methanol was 0.001% v/v. Thus, corresponding to a carbon LOD of 0.3 μg C per mL solution. This water-based separation method represents a significant development for green analytical chemistry, as organic solvent wastes are completely eliminated. Moreover, the application of sensitive and selective carbon-based ICP-MS detection following RP separations highlights the method’s potential to be applied for a wide range of food and environmental analyses applications.
The next step in this project involved coupling a hydrodynamic chromatography (HDC) column, suitable for sizing nanoparticles, to ICP-MS, and optimizing it to be used for the detection of nanoplastic particles ranging in size from 50 to 1000 nm. This approach has the potential to rapidly screen environmental and food samples for the presence of nanoplastic particles within this range. This is anticipated to allow for our improved understanding of nanoplastic pollution and behaviour. Ultimately enabling scientists to study their impact on human and animal health, as well as their impact on the environment.
