Bello D, Streicher R P, Woskie S R
University of Massachusetts Lowell, Department of Work Environment, 01854, USA.
J Environ Monit. 2002 Jun;4(3):351-60. doi: 10.1039/b110613a.
This paper evaluates the performance of the NIOSH draft method 5525 for analysis of monomeric and TRIG aliphatic isocyanates in autobody repair shops. It was found that an optimized pH gradient enhanced noticeably the resolution and, therefore, identification of aliphatic isocyanates. Samples proved to be very stable for at least a year when stored at -13 degrees C in the freezer, and no major stability problems were found for the MAP reagent. The detector response factor RSD for selected MAP ureas was 40% in the fluorescence (FLD), 3% in the UV at 254 nm (UV254), and 1% in the UV at 370 nm (UV370). The mean FLD/UV254 and UV254/UV370 detector response ratios of standards were 31.7 (RSD = 37.8) and 17.1 (RSD = 5.4), respectively. The FLD/UV254 ratio in bulks varied from 0.41 to 1.97 times the HDI monomer ratio. The mean UV254/UV370 ratio in bulks was 16.1 (range 14.1 to 19.2, N = 38). Mean (range) recovery of 92 (91.2-93.2)% was found for the N3300 (isocyanurate) spiked on 25 mm quartz fiber filters in the range 0.07 to 2.2 microg NCO ml(-1). Mean (range) recovery for impingers was 100.7 (91.7-106.0)% for N3300 in the concentration range of 0.018 to 2.5 microg NCO ml(-1) and 81.0 (76.1-89.1)% for IPDI in the concentration range of 0.016 to 1.87 microg NCO ml(-1). Analytical method precision was 3.4% and mean bias 7.4% (range = 0-25%). The NIOSH draft method 5525 provides flexibility, enhanced sensitivity and specificity, powerful resolution, and very small compound-to-compound variability in the UV254, resulting in a more reliable identification and quantification of aliphatic isocyanates.
本文评估了美国国家职业安全与健康研究所（NIOSH）方法草案5525用于分析汽车车身修理店中单体和三聚体脂肪族异氰酸酯的性能。研究发现，优化的pH梯度显著提高了脂肪族异氰酸酯的分离度，从而有助于其鉴定。当样品在-13℃的冷冻箱中储存时，至少一年内都非常稳定，且未发现MAP试剂存在重大稳定性问题。选定的MAP脲在荧光检测器（FLD）中的响应因子相对标准偏差（RSD）为40%，在254nm紫外检测器（UV254）中为3%，在370nm紫外检测器（UV370）中为1%。标准品的平均FLD/UV254和UV254/UV370检测器响应比分别为31.7（RSD = 37.8）和17.1（RSD = 5.4）。散装样品中的FLD/UV254比值是六亚甲基二异氰酸酯（HDI）单体比值的0.41至1.97倍。散装样品中的平均UV254/UV370比值为16.1（范围为14.1至19.2，N = 38）。在0.07至2.2μg NCO ml⁻¹范围内，加标在25mm石英纤维滤膜上的N3300（异氰脲酸酯）的平均回收率（范围）为92（91.2 - 93.2）%。吸收管中N3300在0.018至2.5μg NCO ml⁻¹浓度范围内的平均回收率（范围）为100.7（91.7 - 106.0）%，异佛尔酮二异氰酸酯（IPDI）在0.016至1.87μg NCO ml⁻¹浓度范围内的平均回收率为81.0（76.1 - 89.1）%。分析方法的精密度为3.4%，平均偏差为7.4%（范围 = 0 - 25%）。NIOSH方法草案5525具有灵活性、更高的灵敏度和特异性、强大的分离度，并且在UV254中化合物与化合物之间的变异性非常小，从而能够更可靠地鉴定和定量脂肪族异氰酸酯。
