Determination of isocyanates in air

Guglya, Elena B.

doi:10.1007/bf02757805

Cited by 18 publications

(17 citation statements)

References 111 publications

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“…1 As reported, diisocyanates 2 are low molecular weight significantly toxic compounds that violently react with water and other chemicals to cause explosions; however, they are highly valuable in the manufacturing industry of polyurethane-based products such as foams, elastomers and coatings. These products are used everywhere in people's daily life because of their durability against chemical damage, colorfastness, and abrasive resistance.…”

Section: Introductionmentioning

confidence: 99%

“…Both instrumental and continuous monitoring methods have been developed in this regard as reviewed by Guglya. 2 As shown in Table S1, for the instrumental methods, 7 such as high performance liquid chromatography (HPLC), 8, 9 capillary gas chromatography (CGC) with flame ionization 10, 11 and ion chromatography with UV detection, 12, 13 the derivatization and extraction steps are quite time-consuming. Moreover, such offline strategies provide significant statistical differences as compared to online protocols.…”

Section: Introductionmentioning

confidence: 99%

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2,4-Toluene diisocyanate detection in liquid and gas environments through electrochemical oxidation in an ionic liquid

Lü

Rehman

Chi

et al. 2016

Analyst

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The electrochemical oxidation of 2,4-toluene diisocyanate (2,4-TDI) in an ionic liquid (IL) has been systematically characterized to determine plausible electrochemical and chemical reaction mechanisms and to define the optimal detection methods for such a highly significant analyte. It has been found that the use of an IL as the electrolyte allows the oxidation of 2,4-TDI to occur at a less positive anodic potential with no side reactions as compared to traditional acetonitrile based electrolytes. UV-Vis, FT-IR, Cyclic Voltammetry and Electrochemical Impedance Spectroscopy (EIS) studies have revealed the unique mechanisms of dimerization of 2,4-TDI at the electrode interface by self-addition reactions, which can be utilized to improve the selectivity of detection. The study of 2,4-TDI redox chemistry further facilitates the development of a robust amperometric sensing methodology by selecting a hydrophobic IL ([C4mpy][NTf2]) and by restricting the potential window to only include the oxidation process. Thus, this innovative electrochemical sensor is capable of avoiding the two most ubiquitous interferents in ambient conditions (i.e. humidity and oxygen), thereby enhancing the sensor performance and reliability for real world applications. The method was established to detect 2,4–TDI in both liquid and gas phases. The limits of detection (LOD) values were 130.2 ppm and 0.7862 ppm, respectively, for the two phases, and are comparable to the safety standards reported by NIOSH. The as-developed 2.4-TDI amperometric sensor exhibits a sensitivity of 1.939 μA/ppm. Moreover, due to the simplicity of design and the use of an IL both as a solvent and non-volatile electrolyte, the sensor has the potential to be miniaturized for smart sensing protocols in distributed sensor applications.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

2,4-Toluene diisocyanate detection in liquid and gas environments through electrochemical oxidation in an ionic liquid

Lü

Rehman

Chi

et al. 2016

Analyst

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“…Mono-functional NCO are used as intermediates in the production of herbicides, crop-protection agents and anti-diabetic drugs. 1 However, the most important class of NCO for industrial purposes is the di-functional NCO. Diisocyanates, for example, are widely used in the manufacture of polyurethane products such as fl exible and rigid foams, fi bres, coatings such as paints and varnishes, and elastomers.…”

Section: Introductionmentioning

confidence: 99%

Characterisation of Derivatised Monomeric and Prepolymeric Isocyanates by Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight Mass Spectrometry and Structural Elucidation by Tandem Mass Spectrometry

Warburton

Clench

Ford

et al. 2005

Eur J Mass Spectrom (Chichester)

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Isocyanates are an important class of compounds in occupational hygiene monitoring due mainly to their behaviour as respiratory sensitisers. Here, we demonstrate the application of matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) and MALDI tandem mass spectrometry (MS-MS) to the analysis of derivatised isocyanate monomers and prepolymers. The aim of the work has been to gauge the selectivity obtainable from the direct analysis of isocyanate mixtures without prior separation. Monomeric and prepolymeric isocyanate mixtures were analysed as their 1-(2-methoxyphenyl) piperazine derivatives and the potential of MALDI time-of-flight (ToF)-MS for an NCO monitoring program was assessed. The results obtained demonstrated the possibility of direct mixture analysis by this method. MALDI-MS-MS was used for the elucidation of fragment structures in the prepolymer samples. The developed methodology was then applied to the analysis of swabs from an occupational hygiene monitoring scheme and enabled the identification of the isocyanate species detected.

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“…Furthermore, isocyanates have a mutagenic potential through their ready reaction with proteins and DNA to form adducts [5]. A number of different amine reagents have been explored for the sampling of isocyanates, including 1-(2-methoxyphenyl)-piperazine (1-2MP), dibutylamine (DBA), and 9-(N-methylaminomethyl)-anthracene (MAMA) [6 -9], while numerous liquid chromatographic (LC) methods with electrochemical, ultraviolet (UV) or mass spectrometric (MS) detection have been presented for the determination of the isocyanate derivatives [7]. solution containing an amine reagent and/or a filter impregnated with the amine reagent, resulting in the formation of stable, non-volatile urea derivatives of any organic isocyanate present [6].…”

Section: Introductionmentioning

confidence: 99%

Determination of 1-(2-methoxyphenyl)-piperazine derivatives of airborne diisocyanates by packed capillary liquid chromatography with pre-column large-volume enrichment

Molander¹,

Thomassen

Lundanes

et al. 2001

J. Sep. Science

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A reliable, sensitive, and robust two‐valve column‐switching temperature‐programmed packed capillary liquid chromatography method with on‐column ultraviolet detection has been developed and validated for the simultaneous determination of 2,4‐toluene‐diisocyanate, 2,6‐toluene‐diisocyanate, hexamethylene‐diisocyanate, and 4,4‐methylene‐bisphenyl‐diisocyanate in workroom air, based on an established 1‐(2‐methoxyphenyl)‐piperazine derivatization filter sampling method. The isocyanate derivatives were enriched on a 0.32×30 mm 5 μm Inertsil C8 pre‐column using a non‐eluting solvent composition of acetonitrile‐10 mM ammonium formate (pH 4.0) (4 : 96, v/v) at a flow rate of 50 μL/min, prior to back‐flushing on a 0.32 × 250 mm 3‐μm Hypersil ODS column, using a mobile phase composition of acetonitrile‐10 mM ammonium formate (pH 6.0) (40 : 60, v/v) at a flow rate of 5 μL/min. Injection volumes up to 1.0 mL were loaded onto the pre‐column. An initial temperature of 80°C provided beneficial selectivity effects as compared to ambient temperature, providing baseline separation of the 2,6‐toluene‐diisocyanate and hexamethylene‐diisocyanate derivatives. Temperature programming from 80 to 95°C provided efficient elution of late eluting 4,4‐methylene‐bisphenyl‐diisocyanate. The method was validated using spiked filters with 5 to 250 ng of the 2,4‐toluene‐diisocyanate derivative, yielding a coefficient of correlation of 0.997 when using an injection volume of 1.0 mL. The within‐assay (n = 4) and between‐assay (n = 4) precisions were in the range 2.7–29.0 and 2.0–18.0%, respectively, and the within‐ and between‐assay recoveries of the isocyanate derivatives were 92.3–97.8 and 95.4–96.7% for all concentrations except for the lowest level. The mass limit of detection of the isocyanate derivatives for the LC method was in the range 0.12–0.25 ng, corresponding to a concentration limit of detection of 12–23 ng/m3 total isocyanate groups in air using a 15‐L air sampling volume, with 20% sample exploitation, 100% sampling efficiency, and 50% recovery at low concentrations.

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Determination of isocyanates in air

Cited by 18 publications

References 111 publications

2,4-Toluene diisocyanate detection in liquid and gas environments through electrochemical oxidation in an ionic liquid

2,4-Toluene diisocyanate detection in liquid and gas environments through electrochemical oxidation in an ionic liquid

Characterisation of Derivatised Monomeric and Prepolymeric Isocyanates by Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight Mass Spectrometry and Structural Elucidation by Tandem Mass Spectrometry

Determination of 1-(2-methoxyphenyl)-piperazine derivatives of airborne diisocyanates by packed capillary liquid chromatography with pre-column large-volume enrichment

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