环境空气中气态与颗粒态左旋葡聚糖的分析方法

An analytical method for gas and particulate phases of levoglucosan in ambient air

实验通过优化c(Lev)样品采集与前处理,结合高效阴离子交换色谱-脉冲安培法(HPAEC-PAD)分析,建立了气、颗粒两相中Lev的快速分析方法。结果表明,使用中流量主动采样器同时采集气态与颗粒态中Lev时,聚氨酯海绵(PUF)和XAD树酯组成的PUF/XAD/PUF系统(PXP)采集气相样品效果最好;使用水相超声法可有效提取气、颗粒两相样品中的Lev;3个不同浓度梯度(0.02、0.1、1.0 mg/L)的空白加标样的回收率为95.8%~123.0%,且平行样相对标准偏差(RSD)<5%。本方法野外大气采样与分析结果显示:广州大气中气相与颗粒相Lev的均值分别为7.15 ng/m 3和27.9 ng/m 3(两相比值(G/P)=0.25),温度(T)是影响Lev气/颗粒两相分配系数(K p)的主要因素之一。

In this paper,a rapid analysis method for levoglucosan(Lev)in gas and particulate phases has been established by optimizing the method of Lev sample collection,pretreatment,and combining with high-performance anion exchange chromatography-pulse amperometry(HPAEC-PAD)analysis.The results showed that when using the medium flow active sampler to collect Lev in the gas and particulate phases,the PUF/XAD/PUF(PXP)composed of polyurethane foam(PUF)and XAD resin was the best for collecting gas phase samples;aqueous ultrasound method can be effectively employed to extract Lev from gas and particulate two-phase samples;the recoveries of three blank spiked samples with different concentration gradients(0.02,0.1,1.0 mg/L)were 95.8%~123.0%,and the relative standard deviation(RSD)of parallel samples was<5%.Based on analysis of the results obtained from field atmospheric sampling through applying the aforementioned method,mean values of the gas and particulate phases Lev in the Guangzhou atmosphere were 7.15 ng/m 3 and 27.9 ng/m 3,respectively(ratio of Lev in gas phase to particulate phase was 0.25),and the temperature(T)is one of the predominant factors influencing Lev gas/particulate two-phase partitioning coefficient(K p).