乙酰丙酮荧光法在线监测环境空气中的甲醛

我国现行环境空气中甲醛的标准测定方法普遍难以满足当前大气监测中对痕量浓度水平甲醛的监测需要。在乙酰丙酮分光光度法的基础上改进得到的乙酰丙酮荧光法具有更低的检出限和更高的灵敏度，适用于大气中痕量浓度水平甲醛的监测。基于乙酰丙酮荧光法设计了甲醛在线监测系统，并对其主要性能指标进行了评估测试。测试结果显示，该系统的吸收效率为98.9%~100.1%，检出限为0.045 4×10^-9，精密度为0.44%，线性误差为-0.55%，线性范围为0.0~80.0×10^-9，响应时间为282 s，单日零点漂移为-0.04×10^-9~1.33×10^-9，单日跨度漂移为-0.90×10^-9~3.45×10^-9。测试结果表明，其各项性能指标均能满足当前对大气环境中痕量浓度水平甲醛的监测需求。

On-line Monitoring Gaseous Formaldehyde in Ambient Air by Acetylacetone Fluorescence Method

There are several standard monitoring methods for formaldehyde in China, but all these methods can not meet the needs of the trace level formaldehyde monitoring. Based on the acetylacetone spectrophotometry, the improved acetylacetone fluorescence method has lower detection limit and higher sensitivity, which is suited for the trace level formaldehyde monitoring. An on-line formaldehyde monitoring system was designed based on acetylacetone fluorescence method, and its main performance indicators were evaluated and tested. The results showed that the absorption efficiency was between 98.9% and 100.1%, the detection limit was 0.045 4×10^-9 (volume fraction, unless otherwise specified), the relative deviation of precision was 0.44%, the linear error of accuracy was -0.55%, the linear range was between 0.0 and 80.0×10^-9, the response time was 282 s, the zero drift was between -0.04×10^-9 and 1.33×10^-9, and the span drift was between -0.90×10^-9 and 3.45×10^-9, all the above indicators can meet the needs of trace level formaldehyde monitoring.