Related Experiment Video
Updated: May 6, 2026

Capturing Actively Produced Microbial Volatile Organic Compounds from Human-Associated Samples with Vacuum-Assisted Sorbent Extraction
Published on: June 1, 2022
Changes in volatile compounds of human urine as it ages: their interaction with water
Jae Kwak1, Claude C Grigsby, Brittany R Smith
1Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Air Force Research Laboratory, 711th Human Performance Wing/RHXBC, Wright-Patterson AFB, OH 45433, USA.
Abstract:
The urinary odors are commonly perceived as unpleasant. While numerous studies have identified the volatile organic compounds (VOCs) released from urine, the odorants responsible for the urine odor are not well characterized. Furthermore, anecdotal reports suggest that the odor of aged urine is different from that of fresh urine. However, no study has yet to investigate the specific VOCs released from aged urine. In this study, we analyzed and compared the VOCs released from fresh and aged urine samples, investigating the changes in the urinary VOCs as urine aged. We found an overall decrease in concentration of many urinary VOCs, and concluded this was due to the urine evaporating as it aged. On the contrary, some highly water-soluble compounds such as short and branched-chain organic acids and trimethylamine, increased. Their increased release is most likely due to the loss of water and the subsequent release of water-soluble VOCs as urine ages. We suggest that these VOCs may contribute to the odor of the aged urine.
Related Concept Videos
Urine: Physical and Chemical Properties
The concentration of these solutes varies, with urea being the most abundant nitrogenous waste product. Other solutes include sodium, chloride, potassium, phosphate,...
Urine Studies I: Urinalysis
Volatilization
Formation of Dilute Urine
Filtrate Osmolarity in the PCT
Initially, as the filtrate passes through the proximal convoluted tubule (PCT), its...
Physiology of the Genitourinary System III: Urine Concentration and Dilution
Physiology of Urine Formation
Glomerular Filtration
The first stage in urine formation is glomerular filtration. Each kidney contains approximately 1 million nephrons, the functional units of filtration, with a...

