Validation of a Solvent-Free Sampler for the Determination of Low Molecular Weight Aliphatic Isocyanates Under Thermal Degradation Conditions

During the thermal degradation of 1,6-hexamethylenediiso- cyanate-based (HDI) car paint, the eight most abundant isocyanates generated are isocyanic acid, methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, pentyl isocyanate, hexyl isocyanate, and 1,6-hexamethylenediisocyanate. For the first time, a method using solvent-free samplers is proposed and validated for the simultaneous sampling of all these isocyanates. The sampling efficiency during thermal degradation of car paint can be affected by the formation of dust and aerosols and by the emission of many chemicals, such as isocyanic acid, anhydrides, amines, and alcohols that consume the reagent or interfere in the derivatization procedure. Sampling was performed using cassettes containing two 1-(2-methoxyphenyl)piperazine (MOPIP)-coated glass fiber filters (MFs) (∼4.9 mg per filter) and compared with bubblers containing 15 mL of MOPIP solution in toluene (1.0 mg/mL−1) and with bubblers backed with MFs. A DIN 53436 laboratory scal...