SUMMARY
Instrumental analysis of odor is challenging due to the chemical diversity of many important odorants, the high sensitivity required to achieve human odor thresholds, and the dynamic nature of the odor itself. Conventional sensor-based and chromatographic technologies are poorly suited to the task. In this paper, we apply a novel direct mass spectrometric technique—selected ion flow tube mass spectrometry (SIFT-MS)—to the chemical analysis of odor. The SIFT-MS technique provides comprehensive real-time odor analysis through detection and quantitation of all odorants, including aldehydes, amines, organosulfur compounds, and volatile fatty acids. In the case study described, SIFT-MS is utilized to monitor specific odor compounds at a gelatin factory in Christchurch, New Zealand. Odor composition from various steps in the gelatin manufacturing process was determined using SIFT-MS in scan mode. Over a period of several years, the gelatin manufacturer made improvements to their plant to reduce fugitive odors, and sources were re-analyzed. In this investigation, SIFT-MS analysis was utilized to evaluate the effectiveness of an odor neutralization technology based on UV photolysis at the plant.