Application of an integrated PrepStation–GC-NPD system to automated continuous measurement of formaldehyde and acetaldehyde in the atmosphere

摘要: An integrated PrepStation–gas chromatography-nitrogen–phosphorus detection (GC-NPD) system was used for the fully automated, continuous, low parts per billion analysis of lower aldehydes in atmosphere. Analysis involved a solid phase extraction procedure based on collection from air pumped through silica gel cartridge impregnated with acidified 2,4-dinitrophenylhydrazine (DNPH). Automated continuous measurements were performed typical temporal resolution 3 h, including 146 min sampling at constant flow rate 0.15 L min−1 and 34 min preparation several cartridges. samples could be parallel by using previously defined scheduler settings separate, independent software to operate PrepStation module. GC-NPD highly repeatable, relative standard deviations <3.0%. Recoveries all compounds 88–101%. DNPH decomposition products did not adversely affect quantitative determination aldehyde–DNPHs; therefore, it necessary remove excess reagent. The limits quantification (10σ blank hydrazones) formaldehyde acetaldehyde 2.2 1.2 ppb, respectively, 21.9 L (0.15 L min−1 146 min) sample volume. PrepStation–GC-NPD gave results comparable those Sep-Pak method.