The samples were pipetted into 2 mL glass vials. The vials
were full so as to leave no headspace and sealed with Teflonlined
silicon septa and screw caps. One drop of enzyme catalase
was also added to each sample to decompose any residual
hydrogen peroxide and prevent hydrogen peroxide from reacting
with organic substrates during the analysis. Hydrogen peroxide
was measured by the standard iodometric titration method.
Residues of formaldehyde and methanol were determined by
gas chromatography (Perkin-Elmer SIGMA 3 equipped with an
FID Detector (HP 4890)). A pack column (5% diphenyl and
dimethylpolysiloxane) of 60 m and 0.53 m was used.
For the toxicity test, all samples were diluted 16 times before
analysis. Then the toxicity of the solutions was evaluated by
The CellTiter 96® AQueous Non-Radioactive Cell Proliferation
Assay, a colorimetric method for determining the number
of viable cells in proliferation or chemosensitivity assays.