权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of droplet surface applied passive monitoring device for low concentration VOC

液滴表面应用的低浓度VOC被动监测装置研制

基本信息

批准号：
10558085
负责人：
KORENAGA Takashi
金额：
$ 6.14万
依托单位：
University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

We developed the new environmental monitoring instrument of high performance passive sampling by the droplet method based on the research reports given by Dasgupta, et al. We also improved the instrument for producing large droplets. The pumping method of gas-absorbed solution needed high accuracy at very low flow rates for absorption on a flow droplet surface. We used a plunger pump for the absorbed solution and made the stable continuous flow.On the basic experiment for volatile organic compounds (VOC), especially HCHO, passive sampling instruments, constructed instruments were carried out in the same wind tunnel experiment for nitrogen dioxide, and optimized for sampling conditions, for example, a HCHO-absorbed solution flow rate, droplet diameter, temperature, moisture, wind velocity, and so on.A new, simple, sensitive and in-field fluorimetric method for the determination of formaldehyde is proposed. The reaction of formaldehyde with hydralazine in acidic medium, heating on a boiling water-bath for 25 min, produces s-triazolo [3,4-α] phthalazine (Tri-P). the fluorescence intensity of the product formed (Tei-P) was determined at λ em=389 nm with λ ex=236 nm. The fluorescence intensity is linear over a formaldehyde concentration range of 1.2-33.0 μ gl-1. The proposed method was applied successfully to the determination of formaldehyde sampled from the atmosphere using the liquid droplet technique. Formaldehyde vapor in a wind tunnel and that in the droplet. The detection limit for formaldehyde was 2.0 μ gl-1 with RSDs varying from 3 to 12% in ambient air, using a droplet correction solution (boric acid and hydralazine). The effect of interfering substances on the determination shows that most cations and anions did not interfere. The results obtained were satisfactory compared with a reference method.

根据Dasgupta等人的研究报告，我们研制了一种新型的高效无源液滴采样仪。我们还改进了产生大液滴的仪器。气体吸收溶液的泵送方法需要在很低的流速下对流滴表面的吸收有很高的精度。在对挥发性有机化合物(VOC)，特别是甲醛的基础实验基础上，搭建了被动采样仪，在相同的二氧化氮风洞实验中，对甲醛吸收液的流量、液滴直径、温度、湿度、风速等采样条件进行了优化，建立了一种新的、简单、灵敏的现场荧光分析方法。在酸性介质中，甲醛与肼氮在沸水浴中加热25min，生成S-三唑并[3，4-α]二氮杂氮(Tri-P)。在λem=3 89 nm和λex=2 36 nm处测定了产物(TeI-P)的荧光强度。甲醛浓度在1.20-33.0μ·g~(-1)范围内，荧光强度呈线性关系。该方法成功地应用于液滴技术测定大气中的甲醛。风洞中的甲醛蒸气和液滴中的甲醛蒸气。使用液滴校正溶液(硼酸和肼)，甲醛的检出限为2.0μgl-1，环境空气中的相对标准偏差从3%到12%不等。干扰物质对测定的影响表明，大多数阳离子和阴离子不干扰测定。与参考方法比较，结果令人满意。