title: Improvement in the GC-MS method for determining urinary toluene-diamine and its application to the biological monitoring of workers exposed to toluene-diisocyanate.
abstract: OBJECTIVE
  To develop a simple and sensitive GC-MS method for determining toluene-diamine (TDA) in urine and to apply the method for biological monitoring of workers exposed to toluene-diisocyanate (TDI).
  
  
  METHODS
  After acid hydrolysis of 0.1 ml of urine, diluted tenfold with water, for 1.5 h, the free TDA formed was extracted with dichloromethane, and the heptafluorobutyric anhydride derivative was determined by GC-MS. We applied the method to the biological monitoring of 18 workers who were using an 80:20 mixture of 2,4-TDI and 2,6-TDI.
  
  
  RESULTS
  2,6-TDA and 2,4-TDA were simply determined in 7 min by GC-MS. TDA levels in post-shift urine were well correlated with personal exposure levels of TDI. The correlation was improved by correction with creatinine or specific gravity in the 2,6-isomer, but not in the 2,4-isomer because of low exposure levels. From the correlation equation, the 2,6-TDA level (corrected with creatinine), corresponding to the TDI level of 5 ppb, was calculated to be 31.6 mug/g Cre. TDAs in pre-shift urine also correlated significantly with the personal exposure levels of TDIs, although the slope of the correlations for pre-shift samples was 60%-70% of those for post-shift samples. The correlation between 2,4-TDA and 2,6-TDA levels was significant, although the levels of the 2,4-isomer were less than one-tenth of the 2,6-isomers in both air (personal exposure) and urine.
  
  
  CONCLUSIONS
  The present method is simple and practicable and can be useful for biological monitoring of TDI workers.
authors.affiliation: Occupational Poisoning Center, Clinical Research Center for Occupational Poisoning, Tokyo Rosai Hospital 13-21, Omoriminami-4, Ota-Ku, Tokyo 143-0013, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sakai
authors.forename: Yoko
authors.initials: Y
authors.lastname: Morita
authors.forename: Jaehoon
authors.initials: J
authors.lastname: Roh
authors.forename: Hyoungryoul
authors.initials: H
authors.lastname: Kim
authors.forename: Yangho
authors.initials: Y
authors.lastname: Kim
mesh_terms: D000395:Air Pollutants, Occupational / Q000633:toxicity*; D015415:Biomarkers / Q000652:urine; D003404:Creatinine / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D016273:Occupational Exposure; D010655:Phenylenediamines / Q000652:urine*; D013046:Specific Gravity; D014051:Toluene 2,4-Diisocyanate / Q000633:toxicity*
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D010655:Phenylenediamines; D014051:Toluene 2,4-Diisocyanate; D003404:Creatinine; C025235:2,6-diaminotoluene; C010914:2,4-diaminotoluene