Validation of an Improved DNPH Method for Acrolein Sampling

Extended Abstract # 110

Eric Grosjean, Kristia Parker, Marcus Hueppe, and Sucha Parmar

Atmospheric Analysis and Consulting, Inc., 1534 Eastman Avenue, Suite A, Ventura, CA 93003

INTRODUCTION

The standard 2,4-Dinitrophenylhydrazine (DNPH) methods (EPA 0011 and CARB 430) typically used to measure carbonyls emitted from stationary sources are unreliable for measurements of Acrolein. Neither of the above methods are approved or validated for Acrolein. Acrolein and/or once formed Acrolein-DNPH decompose in the high concentrations (2N) of Hydrochloric Acid (HCl) used in these methods1-3. AAC has developed a modified version of these methods in which HCL is substituted with H3PO4, a weaker acid, and an organic layer (Toluene) is added to the sampling solution, which extracts the Acrolein-DNPH while sampling4. During sampling Acrolein is first dissolved in the acidified aqueous DNPH solution where it forms the hydrazone, which is then extracted into the Toluene layer where it is protected from further degradation resulting from contact with the acid. Recovery experiments conducted using gas phase standards of Acrolein in humidified zero air have demonstrated that the proposed improved method is capable of measuring Acrolein concentrations over a wide range (16-2116 μg/m3) with close to 100% efficiency.

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