Air Pollutants, Occupational--analysis Air Pollution, Indoor--analysis Caprylates--analysis Carboxylic Acids--analysis Chromatography, High Pressure Liquid--standards Environmental Monitoring--methods Fluorocarbons--analysis Humans Mass Spectrometry--standards National Institute for Occupational Safety and Health, U.S. Occupational Exposure--analysis Reference Standards Sensitivity and Specificity Specimen Handling--methods Surface-Active Agents--analysis Threshold Limit Values United States United States Occupational Safety and Health Administration