The Research Of The Passive Sampler For The Determination Of The Volatile Organic Chemicals In The Air

Objectives The passive sampler is the device for the determination of thegasform or vapor contaminates in the air, its basic principle is according to themolecular diffusion or permeate in the air. In contrast with the active sampler, Thepassive sampler's main characteristic is that it can be run without the power oraerodynamic force, so it was also called no-power sampler. Except mentioned above,this kind of passive sampler have characteristic of small cubic, light, easily operated,and safe. The device can be used for kinetic monitoring, also can expose the samplerin the air for several hours. which Can be used for the evaluate the environmentquality. Now the passive sampler is becoming the researching center of theenvironment hygiene, occupational hygiene, analytical chemistry, preventionmedicine. This article based on the development, principle and type of the passivesampler, developed two kinds of passive sampler for the determination of severalvolatile organic chemicals in the air. In this article, we develop two kinds of passivesampler, and evaluated their function under the experience condition, the result showthat the passive sampler is suitable for the realistic application, which Can be usedwildly in the environment monitor, analytical chemistry and occupational hygiene.Methods The design of the passive sampler: according to the principle of thepassive sampler, design two kinds of passive sampler, that was tube-type passivesampler and badge-type passive sampler. The selection of the sorbent: xylene,styrene,benzene,toluene use the active carbon as the sorbent, formaldehyde use theDNPH overlay the surface of the silica gel as the sorbent. The function ervaluation:prepare certain concentration xylene, styrene,benzene, toluene formaldehyde in theaerator tank, and then put the the passive sampler at the aerator tank, expose the passive sampler to the chemicals (xylene,styrene,benzene,toluene,formaldehyde)for several hours, and then take the passive sampler out, and determin the chemicalsin order to evaluate the function. The function index include analytical recovery,sampling rate, sampling range, the capacity,the shelf life,the storage stability,theprecision,the environmental factor (temperature,humidity,wind velocity), and so on.Results Evaluate the function of the tube-type and badge-type passive samplerunder the laboratory condition, the result as follows:1.The analytical recovery of the xylene,styrene,benzene,toluene, formaldehydewere 82.14%,79.93%,77.33%,83.08%,81.29%respectively, all of the analyticalrecovery were exceed 75%, which can meet the request of the regulation.2.The sampling rates of the tube-type sampler for the xylene, styrene,benzene,toluene,formaldehyde were 50.00,41.72,55.04,35.01,104.12ml/min, andthe shortest sampling time Was 30 minutes; the sampling rates of the badge-typesampler for the xylene,styrene,benzene,toluene, formaldehyde were 58.66,53.91,67.32,77.74,136.32ml/min, and the shortest sampling time was also 30minutes.3.The sampling scope of the tube-type passive sampler for the xylene,styrene,benzene,toluene was 30-500mg/m~3, for the formaldehyde was 0.2-5.0 mg/m~3; thesampling scope of the badge-type passive sampler for the xylene,styrene, benzene,toluene was 20-500mg/m~3, for the formaldehyde Was 0.2-10.0 mg/m~3.4.the capacity of the tube-type passive sampler for the xylene,styrene,benzene,toluene, formaldehyde were 12.86, 16.09, 10.87, 6.22, 0.256mg; the capacityof the badge-type passive sampler for the xylene,styrene,benzene, toluene,formaldehyde were 18.07,23.49,16.15,9.08,0.3483mg.5.The shelf life of the tube-type passive sampler and the badge-type passive samplerwere more than 30 days.6.The storage stability of the tube-type passive sampler and the badge-type passivesampler were more than 14 days.7.The relative standard deviation (RSD) of the tube-type passive sampler and the badge-type passive sampler were less than 10%.8.Under the temperature 10-40℃,the wind velocity 50-600cm/s and the humidity20%-80%, the passive sampler for the determination of the xylene,styrene,benzene,toluene was not affected, but when the humidity was exceed 60%, thesampling rate for the determination of the formaldehyde was to raise gradually.9.The field experimentation result show that this two kinds of passive sampler weresuitable for the realistic application.Conclusions1.The article mainly design two kinds of passive sampler, which were used fordetermination of the styrene, benzene, toluene, xylene, formaldehyde in the air, basedon the principle of the passive sampler. From the outline to the absortent, the samplerwere designed independently. This two kind of sampler were all easily operated, lightweight, easily to carry, and so on.2.Under the experience the condition, we evaluate the function of the passivesampler for the determination of the styrene, benzene, toluene, xylene, formaldehyde,the result show that analytical recovery, sampling rate,sampling range, the capacity,the shelf life,storage stability,the precision can meet the requirement of the passivesampler, The research above about the passive samplers show that the passivesampler designed by ourselves is suitable for realistic use, especially for theoccupation hygiene and environmental hygiene.