In general, biological samples are easily solubilized in the
presence of tetramethylammonium hydroxide (TMAH) at room
temperature, and do not require the use of energy such as
microwaves or ultrasound or other heating devices, which avoids
volatile analyte loss before analysis. This reagent is a strong
organic base (pH 13.4–14.7) with the chemical formula
(CH3)4NOH, and is soluble in water or alcohols; it is able
to solubilize different kinds of tissues (No´ brega et al., 2006).
Sample treatment using TMAH has been reported for preparation
of biological samples as an alternative to conventional digestion
for the determination of metallic ions by atomic spectrometric
methods