不同溶剂及稀释度对聚氨脂清漆中苯提取效率的影响
Effects of Different Solvents and Dilution Ratios on Benzene Extraction Efficiency in Polyurethane Varnish
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摘要:
目的 考察不同溶剂及稀释度对聚氨脂清漆中苯的提取效率。 方法 用二硫化碳、正己烷、乙酸乙酯、四氢肤喃和甲醇为稀释溶剂,对清漆试样分别按(1+2、1+4、1+6、1+8、1+10)稀释,加入10 μg/mL苯标准后用气相色谱法氢火焰离子化检测器(FID),以聚乙二醇硝基苯改性(FFAP)型毛细管色谱柱分离、测定。 结果 苯的检出限为0.008 4 μg/mL,定量限为0.028 μg/mL,苯在二硫化碳介质中能达到很好的基线分离,不同稀释度的二硫化碳介质中苯的回收率范围为80.9%~96.1%,相对标准偏差(RSD)为1.15%~9.52%,适宜的稀释度应>(1+8),试样的总标准差均<自身浓度的5%;准确度的置信限为0.96。 结论 稀释度过小可导致试样回收率和重复性降低,在最佳条件下试样中苯有良好的精密度和足够的准确度。 Abstract:Objective To examine the efficiency of different solvents and dilution ratios on extracting benzene from polyurethane varnish. Methods Using carbon disulfide, n-hexane, ethyl acetate, tetrahydro-furan, and methanol as diluting solvent candidates, samples were diluted in selected proportions (1+2, 1+4, 1+6, 1+8, 1+10), then added with 10 μg/mL standard benzene solvent. Determination was performed by capillary gas chromatography with free fatty acid phase (FFAP) capillary column and hydrogen flame ionization detector (FID). Results Good baseline separation was achieved by selecting carbon disulfide as solvent and the related detection limit for benzene was 0.008 4 μg/mL, and the quantitative limit was 0.028 μg/mL. The recoveries of benzene with varying carbon disulfide proportions were between 80.9%-96.1%, the relative standard deviation (RSD) was in the range of 1.15%-9.52%, the appropriate dilution level should be greater than (1+8). The general standard deviations of samples were all less than 5% of their concentrations with the confidence limit of 0.96. Conclusion Sample recovery and reproducibility could be reduced by lower dilution level. The benzene determination in described optimal dilution ratio provides ideal precision and sufficient accuracy.
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