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Quantitative determination of total aliphatic isocyanates on skin and surfaces using the map reagent.

Youngs F; Bello D; Woskie S; Streicher R; Liu Y
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana. Fairfax, VA: American Industrial Hygiene Association, 2001 Jun; :70-71
There is increasing interest in the effects of dermal exposure to isocyanates. One of the limitations with determining dermal exposures has been the lack of a suitable analytical method for the quantification of isocyanates sampled from skin and work surfaces. Sample preparation and analysis were performed according to NIOSH draft Method 5525 for total aliphatic isocyanates in air with some modifications. The pads, impregnated with polypropylene glycol, were obtained from a commercial source. Once a surface or area of skin has been wiped, the pad is placed in the field in a solution of 1-(9-anthracenylmethyl) piperazine (MAP) in methylene chloride for immediate extraction and reaction. Samples are subsequently acetylated to react with excess MAP reagent then processed through a 0.45um filter and a reversed-phase, solid phase extraction (SPE) cartridge. The SPE cartridge significantly reduces interferences from surface and skin wipe samples. The compounds of interest are eluted from the SPE cartridge with acetonitrile and methanol. The analytical method LOD has been conservatively estimated to be 10 ng for both HDI and IPDI. Laboratory spiking of pads was performed to determine extraction efficiency. Pads were spiked with oligomers of HDI isocyanurate (n=24) and IPDI (n=21) at seven different concentrations, ranging from 0.067 to 3.1 and 0.041 to 1.1 ug NCO, respectively. Recoveries for HDI and IPDI were found to be concentration dependent. Correction factors for the recovery of HDI and IPDI were determined from the regression equations of spiked versus recovered oligomer. The HDI oligomer showed an average recovery of 79% while the IPDI oligomer showed an average recovery of 66%. The skin and surface wipe method described here is shown to be a sensitive and reliable approach for the quantification of total aliphatic isocyanates.
Skin-exposure; Isocyanates; Work-areas; Sampling-methods; Analytical-methods; Analytical-processes; Analytical-chemistry; Aliphatic-compounds
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American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana
Page last reviewed: March 25, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division