Determination of unreacted 2,4-toluene diisocyanate ( XXXX ) and 2,6-toluene diisocyanate (2,6TDI) in foams at ultratrace level by using HPLC-CIS-MS-MS.

@entity20312 @entity61821 @entity10225 @entity1091 @entity7446
@entity10225 can cause @entity7446 . By using available HPLC-UVF methods, @entity10225 can be quantified only at levels above 1% of the Permissible Exposure Limits (PEL). Once sensitized, workers can react to concentrations below these limits of detection (LOD) making these methods insufficiently sensitive to adequately evaluate trace amounts of @entity10225 present in air or in materials at safe levels for sensitized workers. This article describes a novel method for isocyanate analysis allowing the quantification of @entity61821 and 2,6TDI monomers at very low concentrations using HPLC-CIS-MS-MS. The method's sensitivity increases with a decrease in the alkali radius. The LOD is 0.039 ng mL(-1) for @entity61821 and 0.100 ng mL(-1) for 2,6TDI in solution when @entity1091 is the alkali adduct, which is 20 times more sensitive than HPLC-UVF method. This new method allows determination in foam at levels of 0.078 ng g(-1) for @entity61821 and 0.200 ng g(-1) for 2,6TDI respectively, for a 0.5 g foam sample. This is more than 100 times more sensitive than other methods for determining free monomers in solid materials. Analytical reproducibility and precision are better than 92% and 93% for both @entity20312 monomers. The use of HPLC-UVF conventional method failed to detect unreacted @entity10225 in foam samples, but TDI monomers were quantified by HPLC-CIS-MS-MS.
