Investigation of the ability of MDHS method 25 to determine urethane-bound isocyanate groups.
Streicher RP; Arnold JE; Cooper CV; Fischbach TJ
Am Ind Hyg Assoc J 1995 May; 56(5):437-442
A study was conducted on the ability of Method 25 for the Determination of Hazardous Substances (MDHS-25) of the Health and Safety Executive of the United Kingdom to identify and quantitate free isocyanate containing intermediates created during the formation of polyurethane. The MDHS-25 procedure involved derivatization of isocyanate species with 1-(2- methoxyphenyl)piperazine (MOPP) followed by analysis with high performance liquid chromatography with tandem ultraviolet/electrochemical detection. Model urethane species, containing two and three toluene-diisocyanate (TDI) units and terminal MOPP derivatized isocyanate groups, derived from 2,4- toluene-diisocyanate (584849) (2,4-TDI) and ethylene-glycol (107211) were prepared. Neither the ultraviolet nor the electrochemical detection response was found to be proportional to the number of isocyanate groups present in the model compounds. The authors conclude that MDHS-25 is unable to identify or quantitate TDI/urethane intermediates containing MOPP derivatized isocyanate groups. The authors propose that a derivatizing reagent be used which would give derivatized isocyanate species whose detector responses result from the derivatized isocyanate moiety.
NIOSH-Author; Isocyanates; Analytical-chemistry; Chemical-analysis; Analytical-methods; Laboratory-techniques; Urethanes; Quantitative-analysis; Industrial-hygiene
Robert J. Streicher, Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering, 4676 Columbia Parkway, Cincinnati, OH 45226
American Industrial Hygiene Association Journal