Evaluation of Total Isocyanate-in-Air Method Using 1-(2-Methoxyphenyl)piperazine and HPLC

An epidemiology study of lung function changes of toluene diisocyanate foam workers in the United Kingdom

“…The integrated exposures are considered to be reliable above 4 ppbh; however, below this level, instrumental``noise'' may account for part of the exposure recorded, particularly in those areas where TDI would not have been expected. This was con®rmed by 31 concurrent MCM and high-performance liquid chromatography (HPLC) samples [3] taken in areas where persons from the lowexposure and handling groups were working; recorded TDI concentrations were below the levels of detection (0.1 ppb) for the HPLC method. Given some observed baseline``noise'' on the MCMs, which has a higher detection limit (1 ppb), the assigned exposures for such subjects may have been overestimated.…”

Application of tryptamine as a derivatizing agent for airborne isocyanate determination. Part 4. Evaluation of major high-performance liquid chromatographic methods regarding airborne isocyanate determination with specific investigation of the competitive rate of derivatization

“…In order to satisfy the increasing demand for monitoring both monomeric and polymeric isocyanates, Bagon et al 5 have devised a dual-detection HPLC method using 1-(2-methoxypheny1)piperazine (MPP) as the derivatizing agent. Polymeric components of a particular isocyanate are identified by the ratio of the responses from both the amperometric oxidation and UV detectors.…”

“…As both reactions proceed concurrently at different rates, the combined rate kinetics can be expressed by equation ( 5) with the time variable, t , being considered as a constant (5) By appropriately integrating equation ( 5 ) as shown in equation (6), the relative rate (klk') for the competitive derivatization reaction9910 is finally obtained [equation ( 7…”

Application of Tryptamine as a Derivatizing Agent for the Determination of Airborne Isocyanates.Part 7. Selection of Impinger Solvents and the Evaluation Against Dimethyl Sulfoxide Used in US NIOSH Regulatory Method 5522

“…The expected accuracy of recoveries based on a maximum bias of 5% pump error is 5 + 2 RSD t (i.e., smaller than 25%), which meets the NIOSH criterion specified in the NIOSH Standards Completion Program. 6,8 Also, considering the standard deviations, the relative recoveries using butyl acetate and octane for sampling compared with that of DMSO as the impinger solvent are excellent, as shown in Table 3. The results confirm that these solvents are comparable in to DMSO employed in NIOSH Method 5522.…”