| Title: | Belt-Mounted Micro-Gas-Chromatograph Prototype for Determining Personal Exposures to Volatile-Organic-Compound Mixture Components |
| Author(s): | Wang J; Nunovero N; Nidetz R; Peterson SJ; Brookover BM; Steinecker WH; Zellers ET; |
| Address: | "Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States. Center for Wireless Integrated MicroSensing and Systems , University of Michigan , Ann Arbor , Michigan 48109 , United States. Department of Environmental Health Sciences , University of Michigan , Ann Arbor , Michigan 48109 , United States. Department of Mechanical Engineering , University of Michigan , Ann Arbor , Michigan 48109 , United States. Targeted Compound Monitoring, LLC , Beavercreek , Ohio 45440 , United States" |
| DOI: | 10.1021/acs.analchem.9b00263 |
| ISSN/ISBN: | 1520-6882 (Electronic) 0003-2700 (Linking) |
| Abstract: | "We describe a belt-mountable prototype instrument containing a gas chromatographic microsystem (muGC) and demonstrate its capability for near-real-time recognition and quantification of volatile organic compounds (VOCs) in moderately complex mixtures at concentrations encountered in industrial workplace environments. The muGC comprises three discrete, Si/Pyrex microfabricated chips: a dual-adsorbent micropreconcentrator-focuser for VOC capture and injection; a wall-coated microcolumn with thin-metal heaters and temperature sensors for temperature-programmed separations; and an array of four microchemiresistors with thiolate-monolayer-protected-Au-nanoparticle interface films for detection and recognition-discrimination. The battery-powered muGC prototype (20 x 15 x 9 cm, approximately 2.1 kg sans battery) has on-board microcontrollers and can autonomously analyze the components of a given VOC mixture several times per hour. Calibration curves bracketing the Threshold Limit Value (TLV) of each VOC yielded detection limits of 16-600 parts-per-billion for air samples of 5-10 mL, well below respective TLVs. A 2:1 injection split improved the resolution of early eluting compounds by up to 63%. Responses and response patterns were stable for 5 days. Use of retention-time windows facilitated the chemometric recognition and discrimination of the components of a 21-VOC mixture sampled and analyzed in 3.5 min. Results from a 'mock' field test, in which personal exposures to time-varying concentrations of a mixture of five VOCs were measured autonomously, agreed closely with those from a reference GC. Thus, reliable, near-real-time determinations of worker exposures to multiple VOCs with this wearable muGC prototype appear feasible" |
| Keywords: | "Air Pollution, Indoor/*analysis *Breath Tests/instrumentation Chromatography, Gas *Environmental Monitoring/instrumentation Humans Volatile Organic Compounds/administration & dosage/*analysis;" |
| Notes: | "MedlineWang, Junqi Nunovero, Nicolas Nidetz, Robert Peterson, Seth J Brookover, Bryan M Steinecker, William H Zellers, Edward T eng R01 OH010297/OH/NIOSH CDC HHS/ Research Support, N.I.H., Extramural 2019/03/07 Anal Chem. 2019 Apr 2; 91(7):4747-4754. doi: 10.1021/acs.analchem.9b00263. Epub 2019 Mar 19" |
