Abstract
Background. Selected ion flow tube mass spectrometry allows trace gas quantification in exhaled breath and in the air/vapor above liquids (headspace) down to the 10 parts-per-billion level. During selected ion flow tube mass spectrometry investigation of the volatile compounds emitted by urine, high acetone levels were incidentally identified in the headspace of urine from healthy female volunteers around their mid-cycle. Hence, this study was designed to measure urine headspace acetone levels throughout the menstrual cycle. Methods. Using selected ion flow tube mass spectrometry we measured daily urine headspace acetone concentrations of seven ovulating (group 1) and three postmenopausal volunteers (group 2). Results. A several-fold increase in urine headspace acetone level was detected 2–3 days after the predicted day of ovulation in 5 of the 7 volunteers in group 1. No such rise was detected in group 2. Conclusion. This study provides the basis for future research to understand the reason for and the potential utility of this phenomenon.