采用DNPH衍生法和高效液相色谱(HPLC)技术对生物柴油发动机尾气中的羰基化合物(醛、酮)进行了捕集和分离测定.优化了液相色谱的分离条件,考察了臭氧对检测结果的影响以及采样柱的洗脱效率。结果表明.采用梯度淋洗可以得到较好的分离效果。尾气中的臭氧会导致检测精度降低17%,乙腈的洗脱效率可达90%以上,DNPH衍生法是醛、酮类物质分析测定较为理想的方法。
The carbonyl compounds, which were aldehyde and alkone, from hiodiesel engine exhausts were trapped and then separated and measured with the DNPH and HPLC technology. The separation condition of liquid chromatography was optimized, the influences of ozone on aldehyde and ketone emission were analyzed, and the elution efficiency of sampling column was studied. The result shows that the good separation effect is acquired by using the gradient elution. , The precision of measurement is reduced by 17% due to the ozone existence in the exhaust. With the technology, the elution efficiency of methyl cyanide is beyond 90%. Accordingly, the DNPH is the feasible method to measure the aldehyde and ketone emission.