Hexamethylene tetramine (hexamine) in phenol‐formaldehyde and urea‐formaldehyde moulding compounds can be determined by non‐aqueous titration in acetic acid solution with perchloric acid. Phenolic compounds may be dissolved directly in glacial acetic acid and the hexamine may be titrated. However, hexamine must first be extracted from dry urea‐formaldehyde samples with chloroform before titration as the resin interferes with the titration. Nuclear magnetic resonance spectroscopy may also be used to determine the hexamine content of the extracted solution.

Concern about biological terrorism has greatly increased in the 21st century, and correspondingly, so has the need for accurate detection and identification of biological hazards, such as Bacillus anthracis. Optical techniques have been shown to be useful for this purpose. Use of fluorescence lifetimes as a function of emission wavelength for different materials using point- detection methods appears to be an additional viable option. Although the lifetimes range only between 2 and 6 ns, most biological materials tested in this study were distinguishable. A preliminary database has been compiled for use in a possible future detection system.

The well-known paper chromatography method of quantitation by weighing cut out spot areas has been applied to thin layer chromatograms by a simple technique.Separation of phenol and 4,4'-diphenylolpropane was achieved by thin layer chromatography on a 0.2-mm layer of Silica Gel H'(Merck reagent) using two elutions with benzene-methanol-ethyl acetate (90:2:8)' for development. The

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