标准编号：ISO 16702:2007
中文名称：工作场所的空气质量 用1-（2-甲氧基苯基）哌嗪和液相色谱法测定空气中有机异氰酸酯基团的总量
英文名称：Workplace air quality — Determination of total organic isocyanate groups in air using 1-(2-methoxyphenyl)piperazine and liquid chromatography
发布日期：2007-12
标准范围
This International Standard gives general guidance for the sampling and analysis of airborne organicisocyanate (NCO) compounds in workplace air.This International Standard is appropriate for a wide range of organic compounds containingisocyanate functional groups, including isocyanate monomers and prepolymers. Examples of aromaticmonomers include toluene diisocyanate (TDI) (both 2,4- and 2,6-diisocyanatotoluene), naphthyl diisocyanate(NDI) (1,5-diisocyanatonaphthalene) and methylenebis(4-phenylisocyanate) [MDI, systematicallynamed as di-(4-isocyanatophenyl)methane]. Examples of aliphatic monomers include isophoronediisocyanate (IPDI, systematically named as 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane),methylenebis(cyclohexylisocyanate) (hydrogenated MDI, HMDI) and 1,6-diisocyanatohexane (HDI) (alsoknown as 1,6-hexamethylenediisocyanate). Monomers containing a single isocyanate moiety (e.g. methylisocyanate, ethyl isocyanate, phenyl isocyanate, hexyl isocyanate) are produced during thermal degradationof polyurethanes, i.e. flame bonding and laser cutting. Isocyanate polymers, also called polyisocyanates,homopolymers, oligomers or prepolymers, are derived from the diisocyanate monomers by self-condensationor reaction with polyols. Polymeric diisocyanates are widely used in the polyurethanes, paints and coatings,and adhesives industries.This International Standard is appropriate for measuring any product containing free isocyanate groups. It wasdeveloped primarily for the commonly used MDI, HDI, and TDI, and their oligomers and polymers[1]. It hasalso been used for IPDI, HMDI, and NDI, and their oligomers and polymers. The exposure limit forisocyanates in the UK requires measurement of total isocyanate groups, i.e. monomeric diisocyanates,oligomeric, prepolymeric and polymeric diisocyanates and monoisocyanates. Because there are a wide rangeof isocyanate structures and molecular masses, the chromatographic conditions used will need to be variedaccording to the isocyanate formulation being determined. If both isocyanates and amines are believed to bepresent, and both need to be determined, a standard which enables the simultaneous determination of bothamines and isocyanates may be more appropriate[2]. This method has also been modified to allowdetermination of mono-isocyanates produced during thermal degradation[3], the use of mass spectrometricdetection[4] and other sampling equipment, e.g. 37 mm filters and other filter cassettes, but thesemodifications are not covered in this International Standard. If a modified version of this method is being used,it is the responsibility of the user to demonstrate that the modifications are valid.The method is used to determine time-weighted average concentrations of organic isocyanates in workplaceatmospheres, and is suitable for sampling over periods in the range 0,5 min to 8 h. The method is designedfor personal monitoring, but can also be used for fixed location monitoring by suitable modification.The method is suitable for the measurement of airborne organic isocyanates in the concentration range fromapproximately 0,1 μg/m3 to 140 μg/m3 for a 15 l sample volume. The qualitative and quantitative detectionlimits for isocyanate, defined as three times and 10 times the standard deviation of six blank determinations,have been found to be typically between 0,001 μg and 0,004 μg of isocyanate per sample, respectively(EC detection). For a 15 l air sample, these values correspond to qualitative and quantitative detection limits of0,07 μg/m3 and 0,3 μg/m3, respectively.
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