Developing a standard sample of oil products in a water-soluble matrix based on the Pickering emulsion of dielectric oil

Summary

Monitoring water body pollution with oil products involves using standard samples that adequately reproduce the matrix of a real water sample. Existing commercial standard samples (GSO 7117-94, SO NPVM) are either in tableted or liquid form based on dielectric oil. They lack the stage of extraction of oil products from the aqueous phase resulting in a systematic error of analysis. In the study, a standard sample in the form of the Pickering emulsion stabilized by hydrophobic Aerosil R972 and polysorbate Tween-60, based on GK hydrocracking dielectric oil, was developed. The optimal sample composition (72.47% water, 26.4% oil, 1.04% Aerosil R972, 0.09% Tween-60) was matched by systematic varying the phase ratio and stabilizer concentrations. Analytical certification was carried out using the fluorimetric method in a Fluorat-02 analyzer. The developed sample provides for a relative measurement error of 1.9% for oil product concentrations while calibrated with a hexane solution of GC oil – significantly lower than commercially available analogs (41–74%). The metrological stability has been confirmed by storing in the dark at 4–20 °C for at least three months. The sample reproduces the complete analytical cycle (dissolution – extraction – measurement), making it a valuable tool for calibrating fluorimeters used to monitor wastewater of machine building and metalworking plants.

Key words

standard sample , Pickering emulsion , Aerosil , fluriomentry , water matrix , dielectric oil , analytical certification