『Abstract
A novel approach for implementation of sequential extraction
methods using a multisample, solid-phase extraction manifold (SPExMan)
successfully addresses several chronic problems typical of sequential
extraction methods, including (1) sample loss during supernatant
removal and (2) the time- and work-intensive nature of sequential
extraction protocols. Supernatant is removed from SPExMan reaction
vessels through an integrated filter base, eliminating the possibility
of sample loss during supernatant collection. Vacuum manifold
filtration makes it possible to filter multiple samples simultaneously.
These two features of the design result in minimal residual volume
between steps, eliminating the need for wash steps in between
principle extraction steps and for residual volume correction.
The SPExMan system was evaluated for the SEDEX method of quantifying
different forms of phosphorus in sediments. Results from three
different sediment samples analyzed via the classical centrifuge/syringe
filtration SEDEX method and the SPExMan-SEDEX method agree well,
indicating that the SPExMan design is robust for performance of
sequential extraction methods, and that SPExMan-SEDEX data can
be directly compared with classical SEDEX data. Overall, sample
throughput is greatly increased by the SPExMan approach. Materials
chosen for the SPExMan system are compatible with a wide range
of chemical extractants, including corrosives and organic solvents.』
Acknowledgments
Introduction
Materials and procedures
Description of SPExMan and reaction vessel parts and design
SPExMan-SEDEX detailed protocol
Evaluation of data quality and comparison to classical SEDEX
data
Assessment
Discussion
Comments and recommendations
References