Abstract
Mineral oils are a variety of colorless, odorless products derived from crude oil, that
are made up of a complex mixture of compounds. These compounds are collectively
known as mineral oil hydrocarbons (MOH) and can be classified into two major
classes: mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic
hydrocarbons (MOAH). Mineral oil is used in various industries, including the
pharmaceutical, cosmetic and food industries. Therefore, consumers may be exposed
to mineral oil. Consuming certain mineral oil hydrocarbons has adverse effects on
human health; MOSH entails unbranched and branched hydrocarbon chains that can
bioaccumulate in human tissues and it is speculated to be harmful to the liver, while
MOAH consists of aromatic species, which have the potential to be carcinogenic.
Since MOSH and MOAH have distinct health effects, separating and quantifying them
is necessary. There is thus a need for the development of effective analytical
techniques for the detection and quantification of MOSH and MOAH, to safeguard
human health. Currently, solid-phase extraction (SPE), liquid chromatography (LC),
and high-performance liquid chromatography (HPLC) are used to separate MOSH and
MOAH fractions, while gas chromatography (GC-FID) is used for quantification. Using
these approaches is either costly, requires a large solvent volume, or is timeconsuming.
This project developed a cost-effective method for the selective extraction
of mineral oil, separating saturated and aromatic species, using a 3D-printed flow
system to perform droplet-based liquid-liquid extraction with designer solvents.
A 3D-printed flow device was developed with dimensions of 30, 50, and 4 mm, two
1.1 mm inlets, a T-junction mixing point, and a single 0.8 mm channel that leads to the
outlet. The device was designed with Fusion360 and printed with polypropylene using
a Prusa 3Mk+ 3D printer. A deep eutectic solvent containing silver
trifluoromethanesulfonate was successively synthesised, confirmed with Fourier
transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR), and
was used as the acceptor phase. An in-line phase separator was incorporated into the
flow system to improve automation...