Determination of carbonyl compounds in exhaust gas by using a modified DNPH-method

Abstract

The determination of carbonyl compounds in gaseous samples is usually accomplished by enrichment methods, in which 2,4-dinitrophenyl-hydrazine (DNPH) as a derivatization reagent has become established to a large extent. However, the conventional methods of DNPH-impingers and of DNPH-cartridges are applicable to emission measurements in a limited way only, depending on the NO(2)-concentration in the exhaust gas. It could be proved that DNPH-derivatives, as well as DNPH, are also decomposed by NO(2) at a different speed, in which the hydrazones of unsaturated carbonyl compounds are probably more sensitive than those of the saturated carbonyl compounds. In view of this fact, the collecting methods had to be modified to avoid losses with the enrichment. The analysis of the compounds is carried out by HPLC with an effective gradient-system which is able to separate and detect the carbonyl compounds in exhaust gas within 16 min. Furthermore, a simple working-up procedure is presented which facilitates a parallel analysis by GC.

Hydrogen Peroxide, Organic Peroxides and Higher Carbonyl Compounds Determined during the BERLIOZ Campaign

“…Measurements in road tunnels and smog chambers have shown that the influence of NO and NO 2 on PFBHA sorbent tubes is negligible. This is in contrast to the DNPH cartridges (Nishikawa and Sakai, 1995;Lange and Eckhoff, 1996), which show unfavourable effects (degradation products, loss of hydrazones) at higher concentrations of NO 2 . The influence of ozone depends on the sorbent material.…”

Hydrogen peroxide, organic peroxides, carbonyl compounds, and organic acids measured at Pabstthum during BERLIOZ

“…The mean mixing ratio of the n ‐alkanals decrease from acetaldehyde (0.30 ppbv) to n ‐pentanal (0.067), but from n ‐hexanal on, the mixing ratio of the n ‐alkanals more than twice exceed those of the alkanes. If one assumes that the n ‐alkanals are generated from the OH‐initiated oxidation of alkanes, it is evident that this is the mainly the case for species ≤C 5 [ Lange and Eckhoff , 1996]. One must therefore assume that part of the n ‐alkanals >C 5 are biogenically emitted.…”

Electrochemical Impedance Spectroscopic Investigation in Detecting 2,4‐dinitrophenylhydrazine Using Catalytic Effect of Copper at Glassy Electrode

“…The efficient removal of these organic compounds from waste streams has become a significant environmental concern . Among these, 2,4‐dinitrophenylhydrazine is one of the most potent carcinogens belonging to this family which was used firstly as Brady's reagent for the estimation of methyl ketones and other carbonyls compounds but the toxic action on cellular DNA made their use dangerous .…”

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1IntroductionPhenylhydrazine and theird erivatives,k nown as one category of aromatic amines,a re useda sachemical intermediate in the pharmaceutical, agrochemical and chemical industries [1].H owever,t hese compounds are great environmental pollutants,h ighly toxic substances and also exhibitap oor biodegradability.T hey show variety of toxic effects on human health such as:i nducing oxidative damaget oh emoglobin [2],c ancer [3] and decreasing red blood [4].T he efficient removal of these organic compounds from waste streams has become as ignificant environmental concern [5-6].A mong these,2 ,4-dinitrophenylhydrazine is one of the most potent carcinogens belongingtothis family which was used firstly as Bradysr eagent for the estimation of methyl ketones and otherc arbonyls compounds but the toxic action on cellular DNA made their use dangerous [7,8].Several analytical techniques have been applied for the determination of DNPH, including chemiluminiscence [9],s pectrophotometry [10] and chromatography [11]. However, most of these techniques require welle quipped laboratories,t rained personnel, harmful solvents and are time-consuming.In comparison with above mentioned methods,e lectrochemical impedance spectroscopy( EIS) is ar apid and simple electrochemical method, which has been used for corrosion studies,c oatingse valuation, batteries, fuel cells, and material characterization [12].I th as proven to be efficient in the field of chemical analysis due to speed in the acquisition of the results,p ortability and good sensitivity [13].T his techniquei sa ne fficient tool to distinguish the complex electrochemical reactions, along with Faradic and non-Faradic processes [14].T hese advantages make generala pplication of EIS in various electrochemical systems [ 15,16].Theo bjective of this work is to explore the performance of copper (II) ion as an oxidizinga gent for DNPH at ag lassy carbon electrode (GCE) using electrochemical impedance spectroscopy (EIS).

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“…Phenylhydrazine and theird erivatives,k nown as one category of aromatic amines,a re useda sachemical intermediate in the pharmaceutical, agrochemical and chemical industries [1].H owever,t hese compounds are great environmental pollutants,h ighly toxic substances and also exhibitap oor biodegradability.T hey show variety of toxic effects on human health such as:i nducing oxidative damaget oh emoglobin [2],c ancer [3] and decreasing red blood [4].T he efficient removal of these organic compounds from waste streams has become as ignificant environmental concern [5-6].A mong these,2 ,4-dinitrophenylhydrazine is one of the most potent carcinogens belongingtothis family which was used firstly as Bradysr eagent for the estimation of methyl ketones and otherc arbonyls compounds but the toxic action on cellular DNA made their use dangerous [7,8].…”