Adsorption of hormones from serum by carbon embedded depth filters

A composite filter pad formed by embedding activated carbon powder in fibrous matrix was applied for removal of hormones from human serum. Enhanced adsorption was demonstrated through direct comparison between the stacked filter pads and the powered carbon packed in a column both having an equal weight of carbon. In addition, the composite structure offers the advantage of eliminating the carbon fines mixed in the filtrant, avoiding the flow channeling, and providing favorable rate of adsorption. The adsorption of both thyroid hormones T3 (triiodothyronine) and T4 (thyroxine), and steroid hormone, cortisol, by the carbon filter were studied. The effect of pH on hormone adsorption by activated carbon was verified as an important environmental factor, minimum adsorption occurs at the neutral pH. It was found that T4 carrying one more iodine atom than T3 is less effectively adsorped by carbon adsorption from the serum under competitive condition due most likely to their size differences. The filter pad containing 70% activated carbon as adsorbent was fabricated in disk form and stacked in a column for processing bulk volume of biological fluid. Such a device provides an effective means for removal of hormones from biological solutions.