Green analytical chemistry (GAC) aim to reduce the environmental impact of analytical methods and practices1. According to GAC, some of the aspects that should be considered are (1) the selection of reagents and solvents that are less toxic, biodegradable, renewable, or recyclable, (2) the minimization of waste generation and the proper disposal or treatment of the waste and (3) the reduction of energy consumption and the use of renewable or alternative sources of energy.

During last decades, the chemists in Tallinn University of Technology have developed capillary electrophoresis (CE) technique that uses narrow tubes to separate charged molecules in an electric field. The advantages of CE compared to the other methods of chemical analysis its profound correspondence to the principles green analytical chemistry namely: high resolution and efficiency, speed of analysis, Low sample and reagent consumption and ability to separate different types of molecules, including neutral, amphoteric, and chiral compounds. Using alternative solvents such as ionic liquids, supercritical fluids, or deep eutectic solvents, which can have lower toxicity and higher recyclability than conventional solvents.

During recent years, the analytical chemists in the Tallinn University of Technology have advanced CE technology even further towards to the needs of green analytical chemistry. The research group under supervision of Assistant Prof. Jekaterina Mazina-Šinkar has developed miniaturized and portable CE instruments. This instrument is a variation of CE that uses portable and miniaturized devices that can be operated in situ, in the field or in remote locations, which can reduce the need for sample transportation and storage.

Some of the advantages of PCE over ordinary CE are lower power consumption and battery operation, smaller size and weight of the instrument, higher flexibility and mobility for different applications and lower cost and maintenance requirements.

In recent publications, the scientists from Dr Mazina-Šinkar’s group demonstrate the application of the instrument for determination of the rape drug in situ and possibilities of the use of the instrument in citizen science.

Now the group address some of the challenges of PCE compared to CE: lower resolution, limited sample preparation and handling capabilities and environmental interferences and instabilities. Developing reliable and robust methods that can cope with interferences and instabilities due to temperature, humidity, and vibration will help to improve the performance of the portable instrument. Also the group plans to implement quality assurance and control procedures that ensure the accuracy and precision of the results.

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(1)M Kaljurand, M Růžička, J Gorbatsova, J Mazina-Šinkar, Evaluation of different operating modes of an autosampler for portable capillary electrophoresis, Journal of Chromatography A, 1705, 464201, 2023.

(2)M Růžička, M Kaljurand, J Gorbatšova, J Mazina-Šinkar, Autosampler for portable capillary electrophoresis, Journal of Chromatography A 1685, 463619 1, 2022.

(3)M Kaljurand, J Mazina-Šinkar, Portable capillary electrophoresis as a green analytical technology, TrAC Trends in Analytical Chemistry, 116811, 2022.