The carbonyl compounds concentratio

The carbonyl compounds concentrations emitted by
the incense were normalized by the incense mass. The
normalized carbonyl compounds concentrations are
shown in Fig. 3. The figures of two incense categories
(i.e. traditional and aromatic) do not differ significantly
for formaldehyde, acetaldehyde, acetone and methacrolein.
However, aromatic incense types generally have
lower acrolein, butyraldehyde and propionaldehyde
concentrations than traditional ones.