Sample preparation and analysis of solid- bound pharmaceuticals

Pharmaceuticals and personal-care products used by humans are often excreted or washed down drains to wastewater treatment plants, where they can be bound to particulate in sludge or discharged into local waters and eventually bind to sediments. Similarly, antibiotics and hormones that are used in farm animal operations can become bound to manure, soil that is amended with this manure, and also on air particulate originating from those farms. When pharmaceuticals are bound to particles, it is less likely that they will undergo biotransformation. However, these compounds can desorb and become more bioavailable should conditions change, making this process favorable. Therefore, it is important for researchers to report the fraction of pharmaceuticals that are bound to solids in environmental studies instead of just concluding that the pharmaceutical has been biodegraded or otherwise removed from the system.