Chemistry Reference
In-Depth Information
5
Greening Sampling Techniques
José Luis Gómez Ariza and Tamara García Barrera
Departamento De Química Y Ciencia De Los Materiales 'Profesor José Carlos Vílchez Martín',
Universidad De Huelva, Huelva, Spain
Sampling is a very critical operation in analysis which can dramatically affect final results. Preservation
and stabilization reagents such as acids, solvents and buffers, as well as filters, containers and
refrigeration/cryogenic conditions, represent important environmentally detrimental toxic inputs. Since
billions of samples are annually collected for environmental, health or food quality monitoring, the use
of environmental friendly sampling practices can have important consequences. This paper reviews
the more significant proposal for this purpose under the concept of Green Analytical Chemistry. The
application of direct techniques of analysis that avoid sample collection, transport, pretreatment or
preparation, such as ion-selective electrodes, portable X-ray fluorescence spectrometers or remote
analysis techniques represent some examples of new trends in Green Analytical Chemistry. Other
approaches are centered on solventless techniques for sample extraction, especially supercritical fluid
extraction (SFE), membrane extraction systems, and solid phase extraction (SPE). The reduction
of reagents and solvent volumes together with the increase of rate samples in flow-through solid
phase spectroscopic, hollow-fiber GC/HPLC/CE and nanoparticle-based analytical approaches also
represent relevant contributions in this field. Further options in green sampling is related the use of
sensitive probes that work in streams, at in vivo samples and in-field analysis. Finally, automation of
analysis contributes to labor and energy consumption and can be combined with the above approaches
for green analysis and friendly environmental sampling, although many further studies are still required
in this area.
