"Volatile organic compounds are one of the most important pollutants in the atmospheric environment, and more and more monitoring studies are being conducted on them. One of the most effective technologies is the can-sampling-GC / MS combination technology. Highlighting its overview and progress. VOCs Gaseous Contaminant Monitoring: Tank Sampling - Overview and Advances in GC / MS Binding Technology The pollution of gaseous volatile organic compounds (VOCs) is a serious threat to people's health, so its monitoring technology is also more and more research. One tank sampling and GC / MS detection techniques for the determination of VOCs in gaseous pollutants gradually attention. The tank sampling technique is reviewed, and the application of canister sampling and GC / MS in the detection of VOCs in ambient air, indoor air and exhaust gas is mainly introduced. "Volatile organic compounds are one of the major pollutants in the atmospheric environment, and their main components are hydrocarbons, oxygenated hydrocarbons, halogenated hydrocarbons, nitrogen and sulfur hydrocarbons, low boiling point PAHs, etc. Many and complex composition. Volatile organic compounds in the ambient air mainly come from industrial waste gas, automobile exhaust, photochemical pollutants and so on. Most of these compounds are toxic and have some pungent odor. They are easily absorbed by the skin, mucous membranes and the like. They are mutagenic, teratogenic and carcinogenic. They cause immeasurable damage to human health and have drawn increasing attention and become The focus of research at home and abroad. General VOCs sampling analysis methods such as adsorption analysis, thermal desorption, etc., due to poor sensitivity, sampling time, poor versatility and other defects make its use has some limitations. The Summa tank sampling method can overcome the above shortcomings, is the current air sampling method is better. This article details the tank sampling method and its application to gas chromatography / mass spectrometry in VOCs detection. 1 tank sampling technology Tank sampling is mainly through the negative pressure inside the tank automatically capture the scene of the air, can completely restore the state of the scene air. After the gas sample has been collected, it is stored in a Summa tank for a few months, especially if the sample is placed in a silylated Summa tank. Li Zhenguo found that in some cases, the composition of the gas mixture in the gas tank will change so that it can not represent the collected samples. Gas cans have a limited surface area and all gases compete for the available active sites and thus can not determine the absolute storage stability period. Fortunately, under the conditions of normal ambient air usage, even most VOCs stored in the 30-day cans are close Their original concentration. In addition, the tank sampling can also pump pressure technology to increase the sampling volume so that the sample pressure reaches 10 to 20 times the atmospheric pressure, the sample size for analysis increased significantly. Bottenheim et al. Collected samples using a 2.6 L electric polishing tank with a stainless steel pump to bring the tank pressure to a final 2.58 atm. Grosjean et al. Analyzed the air in a Brazilian city using GC-FID and GC-MS combined with electropolishing pots. Using a pump to pressurize the tank to 30 pounds during sampling, the study detected 150 VOCs contained in the air. Therefore, increasing the sample volume under pressure can reduce the impact of contamination and adsorption losses during the sampling process. Summa cans are mainly polished and silanized, including the classic polished Summa stainless steel cans, the standard method used by the U.S. EPA (TO-14, TO-15). Pump sampling the air collected in the tank into a positive pressure, and more for the analysis of non-polar substances. The advantage of this method is that it avoids penetrating decomposition and analysis when the adsorbent is sampled, but the sampling equipment is expensive, the preparation of the standard sample and the cleaning of the can are time-consuming and laborious, and the sample can not be preconcentrated. Stainless steel sampling tank technology in the determination of volatile organic compounds at home and abroad more. Batterman et al., Using a polished Summa canister, found that the half-lives of aldehydes and terpenoids in wet air-filled tanks were 18 days, 24 days in wet nitrogen, and 6 days in dry air when analyzed for storage of volatile organic compounds. Summa tanks require some humidity when storing organic matter. Sampling can be based on the type of sample and the need to connect the flow control valve gas flow rate. Kwangsam et al. Collected air for 6 hours using a 6L tank containing a flow control valve. In addition, he also used a stainless steel sampling jar with polished and electrically passivated inner wall to sample and analyze the volatile organic compounds in the indoor air. In addition, he also connected the restrictor valve, the stainless steel filter head and the sampling pipe to the sampling tank to sample the air in the traffic road Acquisition, sampling flow rate of 30ml / min, each sampling time of 3h. The inner silanized Summa tank is used more in the determination of gaseous contaminants. The polar components such as formaldehyde and the light-carbon compounds C2-C3 components have been excluded from the tank sampling method either because they are unstable in the sampling tank or have difficulties in preconcentration or chromatographic separation, whereas Summa Siding of the tank silanization technology can solve this problem. YIN Yanxin Silanized Summa cans used to sample indoor air in different places such as living rooms, cars and supermarkets. The preconcentrator was used to cool the gas sample and remove water and carbon dioxide. The samples were then automatically introduced into gas chromatograph mass spectrometry to analyze the major Organic Pollutants. The results show that the method of sampling fast and easy, no need to use any organic reagents in the analysis, experimental background less interference, qualitative analysis is accurate. "Although the tank sampling method can simultaneously collect a variety of samples and is fast and easy to use, the method is costly and often can not be accurately calibrated for low concentrations due to the lack of corresponding stable standards, and the limits of detection of the instrument also limit the method The promotion and application. 2-tank sampling - GC / MS Since can sampling is just a sampling of air samples, components of the gaseous VOCs are typically analyzed qualitatively or quantitatively in combination with gas chromatography or GC / MS detection techniques after sample collection during the determination of gaseous VOCs . Gas chromatography is a new separation and analysis method developed rapidly in recent twenty years. It has the characteristics of high efficiency, high selectivity, high sensitivity, fast analysis, wide range of applications and small sample amount, especially for the isomerization The qualitative and quantitative analysis of bulk and multi-component mixtures can play its role more and more, so it has been widely used in the detection of VOCs. "Typical detectors for tank-based gas chromatography include: Flame Ionization Detector (FID), Electron Capture Detector (ECD), Mass Spectrometer Detector (MS), Flame Ionization Detector (FPD) MS is commonly used for the analysis of gaseous VOCs. Airless Bottle,Airless Pump Bottles,Airless Cosmetic Bottles,Cosmetic Airless Pump Bottles Guangzhou Harvest Plastic Products Co., Ltd , https://www.fsharvestp.com