Field performance evaluation during fog-dominated wintertime of a newly developed denuder-equipped PM1 sampler

Singh, Dharmendra Kumar; Lakshay,; Gupta, Tarun

Field performance evaluation during fog-dominated wintertime of a newly developed denuder-equipped PM1 sampler

2014

Singh, Dharmendra Kumar | Lakshay, | Gupta, Tarun

This study presents the performance evaluation of a novel denuder-equipped PM₁(particles having aerodynamic diameter less than 1 μm) sampler, tested during fog-dominated wintertime, in the city of Kanpur, India. One PM₁sampler and one denuder-equipped PM₁sampler were co-located to collect ambient PM₁for 25 days. The mean PM₁mass concentration measured on foggy days with the PM₁sampler and the denuder-equipped PM₁sampler was found to be 165.95 and 135.48 μg/m³, respectively. The mean PM₁mass concentration measured on clear days with the PM₁sampler and the denuder-equipped PM₁sampler was observed to be 159.66 and 125.14 μg/m³, respectively. The mass concentration with denuder-fitted PM₁sampler for both foggy and clear days was always found less than the PM₁sampler. The same drift was observed in the concentrations of water-soluble ions and water-soluble organic carbon (WSOC). Moreover, it was observed that the use of denuder leads to a significant reduction in the PM positive artifact. The difference in the concentration of chemical species obtained by two samplers indicates that the PM₁sampler without denuder had overestimated the concentrations of chemical species in a worst-case scenario by almost 40 %. Denuder-fitted PM₁sampler can serve as a useful sampling tool in estimating the true values for nitrate, ammonium, potassium, sodium and WSOC present in the ambient PM.

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