Method procedures for sampling aldehyde and ketone using 2,4-dinitrophenylhydrazine—a review

Abstract

Methods for sampling aldehyde and ketone using 2,4-dinitrophenylhydrazine (DNPH) are reviewed with emphasis on the type of trapping media, the absorbing solution composition and stability and the sample flowrate. Pre- and post-sampling procedures are discussed as well as collected sample stability, detection range, contamination and interference. Different methods for generating standard atmospheres are discussed as well as collection efficiency and standards recovery. Aldehyde emissions measured using DNPH in engine exhaust are briefly reviewed with an overview of the effects of fuel type, engine concept and operation and exhaust gas aftertreatment. Finally, practices and recommendations are proposed to ensure the integrity of the sampling process and appropriateness to different applications.

Influences of sampling volume and sample concentration on the analysis of atmospheric carbonyls by 2,4-dinitrophenylhydrazine cartridge

“…In addition, RR values are distinguishable between acetaldehyde and other carbonyl compounds, as the former recorded the highest RR values. The pattern characterized by the relative dominance of acetaldehyde was found persistently under almost all experimental conditions, which complies with previous reports for the cartridge method (2,4-DNPH-coated silica sorbent) [10,17,18].…”

“…However, excessive patterns were also observed at the 20 L sampling volume at S3 and S4 standards. The approaches used for this computation are in accordance with the previous report in that the total molar quantity of carbonyl should consume approximately 75% of the DNPH loading per cartridge (for the safe determination) [18]. …”

“…The cartridge-based sampling method is an easy, simple, and economic technique in the routine analysis of carbonyls in air [16,17]. However, it is found that the efficiency of the cartridgebased approach is affected by such variables as the quantity of the analytes, sampling flow rate, sampling duration [11,18]. 1 26 In this study, we investigated the experimental biases involved with the 2,4-DNPH-coated cartridge sampling method for the analysis of five carbonyl species (i.e., acetaldehyde, propionaldehyde, butyraldehyde, isovaleraldehyde, and valeraldehyde).…”

Aldehyde, Ketone and Methane Emissions from Motor Vehicle Exhaust: A Critical Review

“…The minimal detectable concentration of aldehydes with these procedures is about 0.2 ppm (National Research Council, 1981). Common carbonyls that have been quantified using this method are shown in Table 11 (Yacoub, 1999). Principal reaction of DNPH method is nicely describeb by Yacoub (1999).…”

“…Common carbonyls that have been quantified using this method are shown in Table 11 (Yacoub, 1999). Principal reaction of DNPH method is nicely describeb by Yacoub (1999). Aldehyde and ketone react with DNPH in the presence of an acid to form stable hydrazone derivatives.…”