A reactive and sensitive diffusion sampler for the determination of aldehydes and ketones in ambient air
A reactive and sensitive diffusion sampler for the determination of aldehydes and ketones in ambient air
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用于测定环境空气中醛类和酮类的反应灵敏扩散采样器
DOI：
10.1016/s1352-2310(98)00427-0
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发表时间：
1999
影响因子：
5
通讯作者：
Shuji Hasegawa
中科院分区：
文献类型：
--
作者：
S. Uchiyama;Shuji Hasegawa
我们开发了一种适用于低浓度有机羰基化合物(醛和酮)的采集和分析的扩散进样装置(DSD-羰yl)。该采样装置由聚四氟乙烯(PPTFE)多孔管暴露部分、聚丙烯(PP)管分析部分和2，4-二硝基苯肼(DNPH)包覆硅胶(DNPH-SiO_2)吸收部分三部分组成。醛和酮通过PPTFE管以分子扩散的方式扩散到DSD-羰基上，并与DNPH发生特异性反应，生成稳定的DNPH-衍生物。通过改变DSD-羰基的姿势，通过将吸收剂从曝光部分移动到分析部分来控制收集。用乙腈直接从DSD-羰基的分析部分洗脱DNPH-衍生物，并用高效液相色谱(HPLC)进行分析。DSD-羰基的优点如下：(1)DSD-羰基可用于大气中多种浓度的醛和酮，因为DSD-羰基暴露部分具有可变的扩散面积；(2)DNPH-衍生物从DNPH-硅胶中洗脱，不受空气污染。(3)采样器与泵连接即可用于主动采样。主要醛、酮的检出限为0.072~0.13 ppb，定量限为0.24~0.42 ppb。实验室空气中主要醛和酮浓度的变异系数(CV)在2.5-3.0%之间。甲醛法与活性取样法(美国环保局IP-6A法)具有良好的相关性(R2=0.995)。对甲醛、乙醛和丙酮的吸收速率分别为0.078、0.062和0.079nmolppb-1h-1。使用DSD-羰基可以高灵敏度和高精度地估计大气中的醛和酮，单位为百万分之(Ppb)。
We developed a diffusive sampling device (DSD-carbonyl) for organic carbonyl compounds (aldehydes and ketones) which is suitable for collection and analysis of low concentration levels. This sampling device is composed of three parts, an exposure part made of a porous polytetrafluoroethylene (PPTFE) tube, an analysis part made of polypropylene (PP) tubing and an absorbent part made of 2,4-dinitrophenylhydrazine (DNPH) coated silica gel (DNPH-silica). Aldehydes and ketones diffuse to the DSD-carbonyl through PPTFE-tube by the mechanism of molecular diffusion and react specifically with DNPH to form a stable DNPH-derivatives. Collection is controlled by moving the absorbent from the exposure part to the analysis part by changing the posture of the DSD-carbonyl. DNPH-derivatives were eluted from an analysis part of DSD-carbonyl with acetonitrile directly and analyzed by high performance liquid chromatography (HPLC). The advantages of the DSD-carbonyl are the following: (1) The DSD-carbonyl can be used in a wide range of concentration of aldehydes and ketones in atmosphere, as the DSD-carbonyl exposure part has a variable diffusion area, (2) DNPH-derivatives are eluted from DNPH-silica without contamination of air. (3) The sampler can be applied to active sampling by connecting it with a pump. The limit of detection (LOD) for concentrations of major aldehydes and ketones ranged from 0.072 to 0.13ppb, and the limit of quantitation (LOQ) ranged from 0.24 to 0.42ppb. The coefficient variation (CV) for concentrations of major aldehydes and ketones ranged from 2.5 to 3.0% in laboratory air. The DSD-carbonyl method and active sampling method (US EPA method IP-6A) showed a good correlation (formaldehyde, r2=0.995). The uptake rates for formaldehyde, acetaldehyde, and acetone were estimated as 0.078, 0.062 and 0.079nmolppb-1h-1, respectively. It is possible to estimate atmospheric aldehydes and ketones at parts per billion (ppb), with high sensitivity and precision, by using DSD-carbonyl.