Qiu-liang Cai , Lei Tong , Ning Zhong , Jie Zheng , Meng-meng He , Hang Xiao
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引用次数: 0
Abstract
The Flow Through Sampler (FTS) serves as an efficient wind-powered active sampling device, enabling the collection of a significant air volume within a short duration. Throughout the actual sampling process, the sampling rate of FTS experiences continuous fluctuations, highlighting the need for in-depth investigation into its impact on breakthrough. In this study, we interconnected the FTS sampling column with three distinct pumps, operating at five varied sampling rates under 293 K and 303 K; and breakthrough profiles of PCBs, PAHs and OCPs on the FTS sampling column were investigated to understand the impacts of sampling rate, expressed as linear wind velocity through the cross section of FTS tube (u) on the sampling efficiency of the sampling column. It revealed that the number of theoretical plates (N) and the logarithm of breakthrough volume (logVB) of compounds on the FTS-PUF column exhibit linear relationships with the inverse of wind velocity (1/u). The slopes of the fitted lines (KNu) are closely associated with the volatility of the compounds. Compounds with volatility experience a greater impact from variations in wind velocity on their N value on the sampling column. The effect on the most volatile PCBs surpasses that of PAHs and OCPs. Moreover, the slopes of logVB for different compounds affected by wind speed (KVB-u), display a significant correlation with compound volatility (logPL). Wind speed exerts a stronger influence on the breakthrough volume of low volatile compounds compared to volatile compounds. Multiple linear regression and LSER analysis further confirms a significant positive correlation between N and logVB across different temperatures and wind velocities (log(VB/m3)=2010/(T/K)-0.00066/(u/(m/s))+0.55N-5.41, R2=0.83, n = 423, p = 0). Therefore, the collection performance of the FTS-PUF sampling column for all types of compounds can be predicted under varying temperatures and wind velocitiess/sampling rates. Given the known sampled air volume, the breakthrough level for any chemicals can be estimated, which provids valuable data support for accurate monitoring of atmospheric organic pollutant concentrations.
期刊介绍:
The Journal of Chromatography A provides a forum for the publication of original research and critical reviews on all aspects of fundamental and applied separation science. The scope of the journal includes chromatography and related techniques, electromigration techniques (e.g. electrophoresis, electrochromatography), hyphenated and other multi-dimensional techniques, sample preparation, and detection methods such as mass spectrometry. Contributions consist mainly of research papers dealing with the theory of separation methods, instrumental developments and analytical and preparative applications of general interest.