Porous extraction paddle: a solid-phase extraction technique for studying the urine metabolome.
BACKGROUND
A method was needed to accomplish solid-phase extraction of a large urine volume in a convenient way where resources are limited, towards a goal of metabolome and xenobiotic exposome analysis at another, distant location.


METHODS
A porous extraction paddle (PEP) was set up, comprising a porous nylon bag containing extraction particles that is flattened and immobilized between two stainless steel meshes. Stirring the PEP after attachment to a shaft of a motor mounted on the lid of the jar containing the urine accomplishes extraction. The bag contained a mixture of nonpolar and partly nonpolar particles to extract a diversity of corresponding compounds.


RESULTS
Elution of a urine-exposed, water-washed PEP with aqueous methanol containing triethylammonium acetate (conditions intended to give a complete elution), followed by MALDI-TOF/TOF-MS, demonstrated that a diversity of compounds had been extracted ranging from uric acid to peptides.


CONCLUSIONS
The PEP allows the user to extract a large liquid sample in a jar simply by turning on a motor. The technique will be helpful in conducting metabolomics and xenobiotic exposome studies of urine, encouraging the extraction of large volumes to set up a convenient repository sample (e.g. 2 g of exposed adsorbent in a cryovial) for shipment and re-analysis in various ways in the future, including scaled-up isolation of unknown chemicals for identification. Copyright © 2016 John Wiley & Sons, Ltd.
Department of Pharmaceutical Sciences and Barnett Institute, Bouve College, Northeastern University, Boston, MA, 02115, USA.
Gang
G
Shao
Department of Engineering, College of Engineering, Northeastern University, Boston, MA, 02115, USA.
Michael
M
MacNeil
Department of Pharmaceutical Sciences and Barnett Institute, Bouve College, Northeastern University, Boston, MA, 02115, USA.
Yuanyuan
Y
Yao
Department of Pharmaceutical Sciences and Barnett Institute, Bouve College, Northeastern University, Boston, MA, 02115, USA.
Roger W
RW
Giese