The study of chemical reactions on a very short time scale, often using pulsed lasers.

Unit of time equal to one quadrillionth of a second (10-15s) or one thousandth of a nanosecond.

A laser that emits ultra-fast radiation (ultrashort pulses of light).

Experimental technique used for the study of photochemical reactions. It allows following the time evolution of intermediate species which play an important role in the formation of the reaction products.

A device so constructed that appropriate measurements (as of absorbance) may be made on a flowing liquid.

A probe molecule which reacts selectively with formaldehyde to form a cyclic compound called DDL.

The luminescence of a substance when excited by light or other forms of electromagnetic radiation. In most cases, fluorescence occurs when a molecule absorbs light photons from an ultraviolet (or visible) light source (this is known as excitation) and then rapidly emits light photons back, as it returns to its ground state. Fluorescence phenomena are therefore based on the property of molecules to absorb light at a particular wavelength and to subsequently emit light of longer wavelength after a brief interval.

Measurement based on detecting the light emitted as a result of fluorescence.

Fluorescence spectroscopy is used by scientists in order to identify and analyze fluorescent samples at very low concentration (in the parts per billion range) and also to draw information on the structure, formulation, and stability of the fluorescent substances. Fluorescence spectra are produced when ions or molecules absorb electromagnetic radiation at short wavelengths (higher energy), which then radiate back at longer wavelengths (lower energy).

The simplest aldehyde, H2CO, and a central building block in the synthesis of many other compounds. At standard temperature and pressure it is a flammable, poisonous, colourless gas with a suffocating odour. Formaldehyde was discovered by Wilhelm Von Hofmann and Alexander Butlerov in 1867. It was not until 1892, though, when Friedrich Von Stradonitz managed to isolate and purify this substance.

A 10% solution of formaldehyde in water used as a disinfectant or to preserve biological specimens.