Table 6 Summary of the derivatisation reagents and suitable detections methods used for sampling isocyanates. The advantages and disadvantages with respective reaction are also summarised together with the matrices used for sampling airborne isocyanates and sampling method used in respective study
Derivatisation reagent | Advantages | Disadvantages | Sample | Sampling method | Analytical detection | Isocyanates | Ref |
|---|---|---|---|---|---|---|---|
9-(N-Methylaminomethyl)anthracen (MAMA) | Structure independent (UV) | Light sensitive Interference with amines and alcohols during derivatisation Slow reaction rate | Air (breathing zone) | In-house made, identical to ISO-CHEK (three stage filter cassette) | HPLC-DAD-FL | IPDI monomer, HDI monomer, IPDI polyisocyanate, 3 polyisocyanate forms of HDI | (Reeb-Whitaker et al. 2012) |
Air | Impinger | HPLC-UV | TDI, 2,4-TDA, 2,6-TDA | (Persson et al. 1993) | |||
1-(2-methoxyphenyl)-piperazine (1-2MP) | Signal independent for electrochemical detection (EC) Commercially available internal standards | Underestimation of air-levels during long time sampling Interference with amines and alcohols during derivatisation | Air | Impinger | HPLC-EC and UV | Monomeric | (NIOSH 8/15/94 1994) |
Air | Glass fibre filters | TPMLC | 2,4-TDI, 2,6-TDI, MDI | (Molander et al. 2000) | |||
Air | Impinger, ISO-CHECK, IOM samplers (filter based sampling mainly for particles) | LC-MS, HPLC-UV-FL, HPLC-PDA UV, HPLC-DAD | Mono- and polymeric HDI | (Thomasen et al. 2011) | |||
Air | Impinger | HPLC/MS/MS | ICA, aliphatic isocyanates, alkenyl isocyantes, structural isomers | (Boutin et al. 2004) | |||
Air (breathing zone) | In-house made, identical to ISO-CHEK | HPLC | IPDI monomer, HDI monomer, IPDI polyisocyanate, 3 polyisocyanate forms of HDI | (Reeb-Whitaker et al. 2012) | |||
Personal air, urine | Inhalable dust sampling heads, polystyrene containers | HPLC, negative ion CI MS | MDI, HDI, TDI, IPDI, urinary metabolites of HDI, TDI, MDI, IPDI | (Creely et al. 2006) | |||
Air | Glass fibre filters, bubblers | LC-MS/MS | ICA, linear aliphatic isocyanates, alkenyl isocyanates, HDI, IPDI, 2,4-TDI, 2,6-TDI, MDI, PHI | (Boutin et al. 2006) | |||
Air | Impregnated filters | LC-MS/MS | 2,4-TDI, 2,6-TDI, NDI, MDI, IPDI, PHI, MIC, ICA | (Sennbro et al. 2004) | |||
Air | Glass fibre filter in IOM sampler | LC-MS/MS | HDI based isocyanates | (White 2012) | |||
Air | IOM sampler, impregnated filter | LC/UV/MS | MDI | (Vangronsveld et al. 2010) | |||
Air | Impregnated filters | LC/ESI/MS | TDI | (Mattsson et al. 2008) | |||
1-(9-Antracenylmethyl)piperazine (MAP) | Increased chromatographic performance Quantifies polyisocyanates Near universal UV response factor Sensitive UV detection Compatible with Ph gradient solution | Variable fluorescent yield per NCO Stability of derivatives uncertain Not commercially available MAP artefact peaks | Air | Impregnated filters, impinger, or both | HPLC-UV-FL | Total | (NIOSH 2003) |
Air | Impregnated filters, impinger, or both | HPLC-UV-FL | Monomeric and oligomeric HDI | (Woskie 2004) | |||
Di-n-butylamine (DBA) | No interference with amines and alcohols during derivatisation Can be used in higher concentrations to avoid underestimation Quantifies isocyanates and amines Faster reaction times Commercially available internal standards | Non-routine, expensive analysis Quantifying polyisocyanates requires standards | Air | Impinger and filter | LC-MS/MS | - | (Marand et al. 2005) |
Air | Impinger | HPLC-ESI-MS/MS | HDI and its oligomers | (Pronk 2006) | |||
Air | Impinger | LC-MS/MS | 2,4-TDI, 2,6-TDI. NDI, MDI, IPDI, PHI, MIC, ICA | (Sennbro et al. 2004) | |||
Air | Denuder-impactor | LC-MS/MS | ICA, MIC, EIC, PIC, PHI, HDI, 2,4-TDI, 2,6-TDI, IPDI, MDI | (Dahlin et al. 2008b) | |||
1-(2-pyridyl)piperazine (2-PP) | Separation of isocyanates (mainly monomers) | Polyisocyanates difficult to separate | Gaseous and/or aerosol samples drawn from a emission source | Multicomponent sampling train | HPLC-UV | 2,4-TDI, HDI, MDI, MIC | (EPA 1997) |
Air | Glass fibre filters | HPLC-UV/FL | HDI, 2,4-TDI, 2,6-TDI | (Occupational Safety and Health Administration (OSHA) 1989a) | |||
Air | Glass fibre filters | HPLC-UV/FL | MDI | (Occupational Safety and Health Administration (OSHA) 1989b) | |||
Air | Glass fibre filters | HPLC-UV/FL | 2,4-TDI, 2,6-TDI | (British Standard Institution 2012) | |||
Extracts from solids, soils, filters, foams, collected in impinger solutions | Â | HPLC-DAD/MS | 2,4-TDI, 2,6-TDI, HDI, HDI biuret, HDI trimer, 2,4-MDI, 4,4-MDI | (US EPA 2004) | |||
Air | Filter | HPLC-UV/FL | Di-isocyanates | (Sigma-Aldrich 1994) | |||
Tryptamine | Structure independent reaction | Slow reaction rate Matrix interference when using UV detectors | Air | Impinger | HPLC-FL/EC | - | (NIOSH 1998) |
Air, urine | Impinger | HPLC-EC/UV | HDI | (Mirmohammadi et al. 2010) | |||
9-anthracenylmethyl-1-piperazinecarboxylate (PAC) | No chromatographic losses of isocyanate species No response factor variability between isocyanates | Impurities may give high blank of cleavage product Slow reaction rate | Air | Impinger | HPLC-UV-FL | HDI, PHI, MDI, 2,4-TDI | (Roh et al. 2000) |
Ferrocenoyl piperazide (FP) | Sensitivity | No data on reactivity or stability | Air | Impingers | LC-EC/MS | - | (Seiwert et al. 2004) |