title: Variability in surface infrared reflectance of thirteen nitrile rubber gloves at key wavelengths for analysis of captan.
abstract: The aim of this study was to investigate the surface variability of 13 powder-free, unlined, and unsupported nitrile rubber gloves using attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectrophotometry at key wavelengths for analysis of captan contamination. The within-glove, within-lot, and between-lot variability was measured at 740, 1124, 1252, and 1735 cm(-1), the characteristic captan reflectance minima wavelengths. Three glove brands were assessed after conditioning overnight at relative humidity (RH) values ranging from 2 +/- 1 to 87 +/- 4% and temperatures ranging from -8.6 +/- 0.7 to 59.2 +/- 0.9 degrees C. For all gloves, 1735 cm(-1) provided the lowest background absorbance and greatest potential sensitivity for captan analysis on the outer glove surface: absorbances ranged from 0.0074 +/- 0.0005 (Microflex) to 0.0195 +/- 0.0024 (SafeSkin); average within-glove coefficients of variation (CV) ranged from 2.7% (Best, range 0.9-5.3%) to 10% (SafeSkin, 1.2-17%); within-glove CVs greater than 10% were for one brand (SafeSkin); within-lot CVs ranged from 2.8% (Best N-Dex) to 28% (SafeSkin Blue); and between-lot variation was statistically significant (p < or = 0.05) for all but two SafeSkin lots. The RH had variable effects dependent on wavelength, being minimal at 1735, 1252, and 1124 cm(-1) and highest at 3430 cm(-1) (O-H stretch region). There was no significant effect of temperature conditioning. Substantial within-glove, within-lot, and between-lot variability was observed. Thus, surface analysis using ATR-FT-IR must treat glove brands and lots as different. ATR-FT-IR proved to be a useful real-time analytical tool for measuring glove variability, detecting surface humidity effects, and choosing selective and sensitive wavelengths for analysis of nonvolatile surface contaminants.
authors.affiliation: Department of Health Science and Human Ecology, University of California, San Bernardino, 5500 University Plaza, San Bernardino, California 92407-2397, USA. phalen@csusb.edu
authors.forename: R N
authors.initials: RN
authors.lastname: Phalen
authors.forename: Shane S
authors.initials: SS
authors.lastname: Que Hee
mesh_terms: D002215:Captan / Q000032:analysis*; D020724:Elastomers / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000032:analysis*; D017575:Gloves, Protective; D006813:Humidity; D007202:Indicators and Reagents; D009570:Nitriles / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D020724:Elastomers; D005659:Fungicides, Industrial; D007202:Indicators and Reagents; D009570:Nitriles; D002215:Captan