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1.
用基于气体分子扩散理论研制的被动采样器 (Passivesampler) ,结合Saltzman法 ,离子色谱法 (IC)分析、测定室内空气环境中的NO2 ,利用风洞实验装置进行模拟曝露实验 ,着重研究捕集液的种类、浓度和风洞内NO2 初始浓度、湿度对捕集NO2 能力的影响以及采样器的材料、结构与采样性能的关系。结果表明 ,本文研制的采样器在空气中曝露数个小时后 ,测定空气中NO2 浓度可达n×1 0 μg/L ,与用NOx 分析仪直接测定结果比较误差在 2 0 %以内。本采样器体积小、质量小、结构简单 ,不仅适用于生活环境中NO2 的测定 ,也适用于NO2 个人曝露量的测定  相似文献   

2.
研制了酸度在线检测装置,并应用于溶液酸度在线检测,溶液酸度在线检测装置,设有防污过滤器,自动采样器,蠕动泵,小型管道pH传感器和控制电路等,其特点为防污除油,随机自动采样,定时检测,全部管道化,可单独使用和计算机控制系统联网,适用于溶液酸在线分析,测定精度〈pH0.05。  相似文献   

3.
小型管道PH传感器的研制及其手自动化在线监测中的应用   总被引:1,自引:0,他引:1  
研制了数种结构简单,实用的小型管玻璃膜PH传感器和小型管道PVC膜PH传感器,并将其与普通的酸度计和自动采样器等合理组合,构成了自动采样酸度在线监测装置,该装置与计算机自动化控制系统联网,已用于稀土萃取分离槽液的酸度自动化在线监测,结果满意。  相似文献   

4.
研制了数种结构简单、实用的小型管道玻璃膜pH传感器和小型管道PVC膜pH传感器,并将其与普通的酸度计和自动采样器(自制)等合理组合,构成了自动采样酸度在线监测装置,该装置与计算机自动化控制系统联网,已用于稀土萃取分离槽液的酸度自动化在线监测,结果满意。  相似文献   

5.
专利     
《化学分析计量》2011,(1):64+70
一种水体化学需氧量快速测定装置公开号:CN101900681A公开日:2010.12.01申请人:哈尔滨工业大学摘要一种水体化学需氧量快速测定装置,属于化学分析仪器,解决现有的光催化COD测定装置采用粉末TiO2和附着于反应器壁的TiO2薄膜做为催化剂,粉末TiO2易凝聚、难分离、易失  相似文献   

6.
建立了基于点热源比较瞬时法的热导率测量装置,该装置适合于非电解质和电解质溶液,并可以使实验快速进行,用该装置测定12个原油分在不同温度下的热导率,克服了由于原油中存在极性组分而影响实验结果的困难,关联了馏分热导率与温度,以及馏分的平均分子量,密度,运动粘度和折射率等基本物理性质之间的关系,结果满意。  相似文献   

7.
东洋大学开发出了可检测多酚以及儿茶素等抗氧化物质的传感器芯片,该芯片主要用于测定食品的抗氧化物质含量。检测抗氧化物质时,除了传感器芯片之外还需要有测定装置。相应的测定方法与以前方法不同。该装置传感器芯片与测定装置组合在一起,便于携带,可以像pH计一样轻松地进行测定。  相似文献   

8.
为了提高邻苯二甲酸酯(PAEs)气体采样器的采样效率,研制了PAEs专用气体采样器并对其稳定性和采样效率进行评价。结果表明:该采样器流量的准确性高、稳定性好,可长时间连续采样,连续运行10 h流量降幅低于1%。采用树脂吸附法和滤膜截留法分别收集气固两相PAEs,样品具有代表性,气固两相PAEs回收率均大于85%。采样器适用范围广,可根据气体中PAEs浓度选装1~3层吸附塔,采样效率大于99%,完全满足气体采样效率要求。  相似文献   

9.
建立水中17种氯代有机物的大体积固相萃取–气相色谱检测方法。样品以3.0 mL/min的流量经大体积样品采样器Cleanert PS固相萃取柱富集,真空抽干后用10.0 mL丙酮洗脱,挥干洗脱液,用1.0 mL正己烷定容,在选定的色谱条件下进行分析。17种氯代有机物的质量浓度在0~100μg/L内与色谱峰面积呈良好的线性关系,相关系数均大于0.999,方法检出限为0.002 5~0.074μg/L。样品加标回收率为81.0%~116.0%,测定结果的相对标准偏差为0.56%~6.80%(n=6)。该方法快速、灵敏、准确,重现性好,具有一定的实用价值,适用于水中17种氯代有机物的同时测定。  相似文献   

10.
利用快速定氮装置测定氮   总被引:7,自引:0,他引:7  
一般化验室普遍使用的全量蒸馏装置 [1] (直接加热吸收 ) ,具有准确、重现性好的特点 ,但操作费时。半微量蒸馏装置 [2 ] (水蒸气加热吸收 )具有快速方便的特点 ,但对高含量的含氮样品 ,测定精密度稍差。以上两种装置需用冷凝管通水冷却 ,加热蒸馏吸收和滴定均分二步进行 ,比较麻烦和费时。作者装配的加热抽气吸收测定氮的装置 ,集加热蒸馏吸收滴定于一体 ,不用冷凝管 ,测定速度较快 ,但在操作过程中需经常更换反应瓶 ,而且 Na OH浓度过大 ,容易腐蚀玻璃瓶。本文将水蒸气加热蒸馏装置和抽气吸收滴定装置结合起来 ,组成一套快速可连续测定…  相似文献   

11.
Olansandan  Amagai T  Matsushita H 《Talanta》1999,50(4):851-863
A simple and reliable method was developed for analysis of 18 volatile organohalogen compounds (VOHCs) both indoors and outdoors, consisting of VOHC collection by a passive sampler, extraction with toluene by mechanical shaking, and automatic separation analysis by capillary gas-chromatography with electron capture detector (GC/ECD). The passive sampler is a porous polytetrafluoroethylene (PTFE) tube (30.30+/-0.37 mm net collection length, 5.0 mm inside diameter, 0.990 g weight) uniformly packed with activated charcoal (194.4+/-3.8 mg). The procedure was applied to a field survey on indoor and outdoor VOHC pollution in Shizuoka, Japan. Ten VOHCs, including trichloroethylene, tetrachloroethylene, chloroform, carbon tetrachloride, and p-dichlorobenzene, were detected from indoor and outdoor air samples. The ratios of maximum to minimum VOHC concentrations, both outdoors and indoors, were large. The indoor and outdoor concentrations of 1,1-dichloroethylene, dichloromethane, 1,1,1-trichloroethylene, carbon tetrachloride and trichloroethylene were found to be similar. Indoor concentrations of trihalomethanes, p-dichlorobenzene and tetrachloroethylene were higher than those of outdoors.  相似文献   

12.
The solid phase microextraction (SPME) device with the polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was used as a passive sampler for ambient ozone. Both O-2,3,4,5,6-(pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) and 1,2-di-(4-pyridyl)ethylene (DPE) were loaded onto the fiber before sampling. The SPME fiber assembly was then inserted into a PTFE tubing as a passive sampler. Known concentrations of ozone around the ambient ground level were generated by a calibrated ozone generator. Laboratory validations of the SPME passive sampler with the direct-reading ozone monitor were performed side-by-side in an exposure chamber at 25 °C. After exposures, pyriden-4-aldehyde was formed due to the reaction between DPE and ozone. Further on-fiber derivatizations between pyriden-4-aldehyde and PFBHA were followed and the derivatives, oximes, were then determined by portable gas chromatography with electron capture detector. The experimental sampling rate of the SPME ozone passive sampler was found to be 1.10 × 10−4 cm3 s−1 with detection limit of 58.8 μg m−3 h−1. Field validations with both SPME device and the direct-reading ozone monitor were also performed. The correlations between the results from both methods were found to be consistent with r = 0.9837. Compared with other methods, the current designed sampler provides a convenient and sensitive tool for the exposure assessments of ozone.  相似文献   

13.
A passive “badge-type” sampling device for the determination of gaseous ammonia was developed. The collection substrate is phosphoric acid. The sampler can be used for outdoor and indoor sampling of ammonia in the concentration range from 0.05 μg/m3 to 10 mg/m3. The performance was tested in the laboratory and in the field against an annualar denuder, a filter pack and an impinger technique. The intercalibration showed that the passive sampler compares very well with active samplers (r2=0.99; k=1.05). The average reproducibility of the sampler was 8%. Hence the badge sampler is well suited for the determination of ammonia in a wide range of concentrations and particularly for application under rural background conditions. The sampling rate of the device was calculated according to a simple multi-layer model.  相似文献   

14.
A passive air sampler, using 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole, was evaluated for the determination of formaldehyde in indoor environments. Chromatography paper cleaned using a 3% hydrogen peroxide solution was experimentally determined as being the optimum absorption filter for the collection of formaldehyde (0.05 microg cm(-2) formaldehyde). From a linear-regression analysis between the mass of formaldehyde time-collected on a passive air sampler and the formaldehyde concentration measured by an active sampler, the sampling rate of the passive air sampler was 1.52 L h(-1). The sampling rate, determined for the passive air sampler in relation to the temperature (19 - 28 degrees C) and the relative humidity (30 - 90%), were 1.56 +/- 0.04 and 1.58 +/- 0.07 L h(-1), respectively. The relationship between the sampling rate and the air velocity was a linear-regression within the observed range. In the case of exposed samplers, the stability of the collected formaldehyde decreased with increasing storage time (decrease of ca. 25% after 22 days); but with the unexposed samplers the stability of the blank remained relatively unchanged for 7 days (decrease of ca. 37% after 22 days). The detection limits for the passive air sampler with an exposure time of 1 day and 7 days were 10.4 and 1.48 microg m(-3), respectively.  相似文献   

15.
A simple and cost effective permeation passive sampler equipped with a polydimethylsiloxane (PDMS) membrane was designed for the determination of time-weighted average (TWA) concentrations of volatile organic compounds (VOCs) in air. Permeation passive samplers have significant advantages over diffusive passive samplers, including insensitivity to moisture and high face velocities of air across the surface of the sampler. Calibration constants of the sampler towards 41 analytes belonging to alkane, aromatic hydrocarbon, chlorinated hydrocarbon, ester and alcohol groups were determined. The calibration constants allowed for the determination of the permeability of PDMS towards the selected analytes. They ranged from 0.026 cm2 min−1 for 1,1-dichloroethylene to 0.605 cm2 min−1 for n-octanol. Further, the mechanism of analyte transport across PDMS membranes allowed for the calibration constants of the sampler to be estimated from the linear temperature programmed retention indices (LTPRI) of the analytes, determined using GC columns coated with pure PDMS stationary phases. Statistical analysis using Student's t test indicated that there was no significant difference at the 95% probability level between the experimentally obtained calibration constants and those estimated using LTPRI for most analyte groups studied. This correlation allows the estimation of the calibration constants of compounds not known to be present at the time of sampler deployment, which makes it possible to determine parameters like total petroleum hydrocarbons in the vapor phase.  相似文献   

16.
A rapid and simple sampling technique for use in conjunction with commercial ion mobility spectrometric detectors is described. The technique may be used for the detection of chemical warfare agents in the field. A plastic syringe with a steel needle was attached to the nozzle of the detector, and the syringe shortened to reduce the dead volume in the interface. After heating samples of protective clothing in closed headspace vials to 70 °C for three minutes, the detector with the syringe and needle (called HS-LCD) was used to penetrate the vial and the overpressure was transferred to the detector via the simple interface. The detector response was registered in realtime. To demonstrate the possibilities with this technique, the HS-LCD sampler was tested in the field at relatively low temperatures on pieces of protective clothing contaminated by the chemical warfare agent simulants methyl salicylate and dipropylene glycol methyl ether. A significant improvement in detector response was observed utilising this technique compared to using the detector to survey the material in the open air. This improvement is believed to increase with decreasing ambient temperature and with decreasing analyte volatility. A more comprehensive list of possible interferents should be tested in the future.  相似文献   

17.
A passive sampler method has been developed for ozone monitoring. The method involves a badge type passive sampler and is applied to the analysis of ozone exposure as an indoor and outdoor air pollutants. The passive sampler used in this experiment consists of glass fiber filter coated with NaNO(2), Na(2)CO(3) and ethylene glycol, and diffusion filter to remove the wind effects and several spacer effects. The principle component of coating is nitrite ion, which in the presence of ozone is oxidized to nitrate ion on the filter medium and then analyzed by ion chromatography. The results from laboratory and field tests show excellent correlation between the passive method and standard ozone monitoring system, integrated over the same time period. The wind tunnel parameters that were examined show that determination of relative humidity (ranging from 30 to 80%), temperature (ranging from 10 to 20 degrees C) and wind velocity ( ranging from 0.5 to 1.5 m s(-1)) at typical ozone levels (1-40 ppb) do not influence sampler performance. The detection limit attained 0.1 ppb is adequate for the determination of ozone in indoor and outdoor areas. A statistical comparison with a reference method was done in order to demonstrate the validation of the developed method. The accuracy of the proposed method, expressed as a percent relative error, when compared with a standard reference method, is found to be better than about +/-3.5%. The standard errors of the difference was measured in terms of relative standard deviation (R.S.D.) and it was found that the R.S.D. of the passive sampler for O(3) sampler ranged from 2.0 to 6.0%.  相似文献   

18.
    
A passive badge-type sampling device for the determination of gaseous ammonia was developed. The collection substrate is phosphoric acid. The sampler can be used for outdoor and indoor sampling of ammonia in the concentration range from 0.05 g/m3 to 10 mg/m3. The performance was tested in the laboratory and in the field against an annualar denuder, a filter pack and an impinger technique. The intercalibration showed that the passive sampler compares very well with active samplers (r2=0.99; k=1.05). The average reproducibility of the sampler was 8%. Hence the badge sampler is well suited for the determination of ammonia in a wide range of concentrations and particularly for application under rural background conditions. The sampling rate of the device was calculated according to a simple multi-layer model.Dedicated to Professor Dr. Dieter Klockow on the occasion of his 60th birthday  相似文献   

19.
A simple, highly sensitive analytical method for measuring many kinds of carbonyls in air using a passive sampler containing a sorbent (silica gel) coated with 2,4-dinitrophenylhydrazine has been developed. The carbonyls collected by the sampler were extracted with a solvent, and the extracts were subjected to high-performance liquid chromatography (HPLC; UV detection) without first being concentrated. In this method, the volume injection is examined, and is found to have a sensitivity at least 20 times that of ordinary HPLC methods. The air concentrations of nine carbonyls collected by passive sampling over a period of 24?h were estimated by means of conversion equations derived from the results of active sampling;c?=?10[log ( y )??? b ] a , where c is the carbonyl concentration in air (µg/m3); y is the amount of carbonyl collected by the passive sampler (µg); and a and b are constants for each carbonyl compound. The calculated air concentrations were consistent with the concentrations measured by active sampling. This method may be useful in determining personal exposure to ambient carbonyls.  相似文献   

20.
An analytical method has been developed for the identification and quantification of 20 organic solvent residues in dietary supplements. The method utilizes a headspace sampler interfaced with gas chromatography and flame ionization detection. With split injection (5:1) and a DB-624 column, most of the organic solvents are separated in 9 min. The method has been validated and was found to be relatively simple and fast, and it can be applied to most common organic solvent residues. With the mass detector, the method was able to identify organic solvents beyond the 20 standards tested.  相似文献   

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