title: Use of Raman spectroscopy to identify carbon nanotube contamination at an analytical balance workstation.
abstract: Carbon nanotubes (CNTs) are cylindrical molecules of carbon with diverse commercial applications. CNTs are also lightweight, easily airborne, and have been shown to be released during various phases of production and use. Therefore, as global CNT production increases, so do concerns that CNTs could pose a safety threat to those who are exposed to them. This makes it imperative to fully understand CNT release scenarios to make accurate risk assessments and to implement effective control measures. However, the current suite of direct-reading and off-line instrumentation used to monitor the release of CNTs in workplaces lack high chemical specificity, which complicates risk assessments when the sampling and/or measurements are performed at a single site where multiple CNT types are handled in the presence of naturally occurring background particles, or dust. Herein, we demonstrate the utility of Raman spectroscopy to unequivocally identify whether particulate matter collected from a multi-user analytical balance workstation comprised CNTs, as well as, whether the contamination included CNTs that were synthesized by a Ni/Y-catalyzed electric-arc method or a Co/Mo-catalyzed chemical vapor deposition method. Identifying the exact CNT type generated a more accurate risk assessment by knowing the metallic impurities involved, and it also led to the identification of the users who handled these CNTs, a review of their handling techniques, and an improved protocol for safely weighing CNTs.
authors.affiliation: a Department of Chemistry and Biochemistry , Alan G. MacDiarmid NanoTech Institute, The University of Texas at Dallas , Richardson , Texas.
authors.forename: Elizabeth I
authors.initials: EI
authors.lastname: Braun
authors.affiliation: a Department of Chemistry and Biochemistry , Alan G. MacDiarmid NanoTech Institute, The University of Texas at Dallas , Richardson , Texas.
authors.forename: An
authors.initials: A
authors.lastname: Huang
authors.affiliation: a Department of Chemistry and Biochemistry , Alan G. MacDiarmid NanoTech Institute, The University of Texas at Dallas , Richardson , Texas.
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Tusa
authors.affiliation: a Department of Chemistry and Biochemistry , Alan G. MacDiarmid NanoTech Institute, The University of Texas at Dallas , Richardson , Texas.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Yukica
authors.affiliation: a Department of Chemistry and Biochemistry , Alan G. MacDiarmid NanoTech Institute, The University of Texas at Dallas , Richardson , Texas.
authors.forename: Paul
authors.initials: P
authors.lastname: Pantano
mesh_terms: D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D037742:Nanotubes, Carbon / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis; D016272:Occupational Health; D018570:Risk Assessment; D013059:Spectrum Analysis, Raman / Q000379:methods*; D017132:Workplace
chemical_list: D004391:Dust; D037742:Nanotubes, Carbon
keywords: Nanomaterial occupational hygiene; nanomaterial workplace exposure; nanosafety; safely handling nanopowders