Carbonyls in air: How to optimize the determination method

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Carbonyls in air: How to optimize the determination method

Dear Reader,   

We all know that we need clean air to breathe, but in daily life this fact is often balanced against financial aspects or convenience: What measures are required to clean industrial waste gases? Can we do without the additives that lead to emissions from furniture? How bad is the short drive to the bakery by car? These examples are all relevant sources of exposure to airborne carbonyls.

Carbonyl compounds are not as hot a topic in the media as nitrogen oxides and hydrocarbons, but they are among the most serious chemical hazards in the air. For example two of the most common carbonyl air pollutants formaldehyde and acrolein, are associated with respiratory diseases, autoimmune diseases or even cancer.

Thus the monitoring of carbonyl emissions is an important task and is typically carried out using the DNPH HPLC method, which is described in the DIN ISO 16000-3 standard.

We demonstrate the optimization of this HPLC method and introduce our HPLC system for the determination of DNPH carbonyl derivatives.

The DNPH method

... is suitable for the determination of aliphatic and aromatic aldehydes as well as ketones. The air samples are drawn via cartridges featuring a surface, modified with 2,4-dinitrophenyl hydrazine (DNPH). As samples pass through the cartridge, the carbonyls in the air derivatize to their corresponding hydrazones, which show strong UV activity. The hydrazones are eluted from the cartridge with acetonitrile and can then be separated by HPLC. A well-suited detection wavelength is at 360 nm.

The more carbonyl DNPH derivatives are to be determined in one run, the higher the requirements for resolution and robustness of the separation method.

Application: Method development 13 carbonyl-DNPH derivatives
Optimization of the carbonyl determination

With our application we pursue the goal to determine in one run the 13 carbonyl DNPH derivatives of a standard mix as described in the 2011 version of DIN ISO 16000-3.

With the DryLab® software, the method could be improved from initially only 9 reliably evaluable peaks to all 13 peaks.

An AZURA® Analytical HPLC Plus system with an Eurospher II 100-3 DNPH column was used for the tests.

Visit the application ...
The HPLC system

The AZURA® HPLC system, specially designed for the determination of DNPH-derivatized carbonyls, features a gradient pump for up to 700 bar, an autosampler and a column thermostat for high precision. A diode array detector with 8 channels and a wavelength range of 190-700 nm, equipped with our 50 mm High-Sensitivity LightGuide flow cell is used for the sensitive determination.

This AZURA® Analytical HPLC Plus system is part of our 2018 Promotion Edition.

The system meets demanding analytical requirements and comes with all the important hardware accessories included, from eluent tray and column to capillaries and connectors. With the included Mobile Control touch-optimized device management software, you have all the parameters in view.

This HPLC system supports the ClarityChrom®*, OpenLAB® EZChrom Edition*, and Chromeleon®* software platforms for data acquisition and analysis. For budget-conscious customers, we recommend the popular ClarityChrom® software.

*Chromatography data system not included

Contact for requests or

Learn more about this HPLC system ...
        AZURA® Analytical HPLC Plus system DNPH
AZURA Analytical HPLC Plus system DNPH


June 11–15, 2018 in Frankfurt am Main

KNAUER will be presenting its AZURA® LC systems. The focus is on product purification, ranging from proteins by FPLC to active ingredients with multi-column methods such as SMBC.

Lecture:  Applications of simulated moving bed chromatography for continuous purification of small and large molecules
When?  Tuesday 12, 2018 at 16:30 h
Where?  Room CMF – Conclusio 1

Visit our colleagues in hall 4.1 at booth H8

More about KNAUER at ACHEMA ...
Oliver Gültzow
I hope, you enjoyed reading this issue of the KNAUER e-report. Please contact me for comments and suggestions via the email below.
Thank you from me and the rest of the KNAUER team. Have a nice day!


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