posted on 2024-01-04, 08:29authored byHyunjoo Park, Eunyoung Kim, Taehyun Jun, Sang-Hyun Pyo, Shin-Hyun Kim
Furfural is an intermediary
toxic aldehyde compound produced
during
heat-induced food processing and storage. Furfural is also formed
by the degradation of cellulosic insulation in oil-immersed electric
potential transformers, whose level is an important indicator of aging
for replacement. In this study, we report a new means to detect the
trace level of furfural in a colorimetric manner. Furfural is reacted
with dinitrophenylhydrazine (DNPH) in acid solutions. The colorless
furfural-DNPH compound turns orange-colored as the solution changes
to basic. The delocalization of the π-electron in the DNPH-aldehyde
derivatives at the basic condition causes the shift of the absorption
peak from 318 to 470 nm, which renders the solution orange-colored.
The color and absorbance are saturated in 20 min of incubation. There
is high linearity between the absorbance and the concentration of
furfural in the range of 0–0.2 mM, which enables the quantitative
detection of furfural. The limit of detection is estimated to be as
low as 1.76 μM for the absorbance analysis and 10 μM for
the naked eyes. The colorimetric assay protocol is applicable to the
detection of various aromatic aldehydes, which show strong π-electron
delocalization and is not applicable to aliphatic aldehydes due to
lack of delocalization. This simple assay can be conducted in typical
96-well microplates using a microplate reader, which provides a low-cost
and high-throughput screening. Therefore, we believe that our method
is potentially applicable for the quantitative detection of aromatic
aldehydes in various samples from foods, electronic devices, and so
on.