Fast and Reliable Environmental Analysis of Aldehyde and Ketone Air Pollutants

By: Nicole Amann, AnalytiX Volume 7 Article 2

Sigma-Aldrich presents new GC-MS standards of the derivatization reagent PFBHA and its derivatives with aldehydes and ketones
Product Manager Analytical Standards

Introduction

Aldehydes and ketones are ubiquitous air pollutants. Along with esters and ethers, they are major components of indoor air pollution and are therefore important for industrial hygiene applications. Analytical methods must provide reliable quantification to meet today’s requirements, as well as keep pace with newer and stricter regulations.

Derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) followed by GC analysis provides a fast and reliable way to quantify aldehydes and ketones in ambient air. As with any analytical method, the availability of high quality analytical standards is important to ensure precision and accuracy of the analysis. However, until now the PFBHA derivatives of aldehydes and ketones have not been commercially available. To meet this need, Sigma-Aldrich now offers these derivatives as high purity standards for GC-MS.

PFBHA: Advantages over derivatization with 2,4- DNPH

Derivatization with PFBHA avoids the disadvantages of 2,4-DNPH. PFBHA reacts quantitatively, even with conjugated aliphatic aldehydes. The PFBHA derivatives do not decompose at an elevated temperature. Neither do they require a time-consuming cleanup step. The resulting oximes can be easily resolved by GC.

 

 

Scheme ......... Reaction of PFBHA with aldehyde or ketone to form an oxime

Other Products for Aldehyde and Ketone Analysis from Sigma-Aldrich

Besides the PFBHA reagents, Sigma-Aldrich offers products for both collection, preparation and analysis of aldehydes and ketones.

SPME (Solid Phase Microextraction)

SPME with on-fiber PFBHA derivatization has been applied to environmental monitoring of aldehydes and ketones. The references cited here use a PDMS-DVB fiber coating, which, because of its high affinity for amines, retains the oxime derivatives well. The procedure is simple: soak the fiber in the diluted derivatizing reagent and expose it to the sample headspace or to the air for TWA analysis.

radiello® passive/diffusive samplers

The radiello® passive/diffusive samplers are ideal for long- and short-term sampling of aldehydes and ketones, along with many other analytes, in both indoor and outdoor air. The radial design offers higher capacity and faster uptake/sampling rates than traditional passive monitors. www.sigmaaldrich.com/radiello

Supelco capillary GC columns

For GC analysis of the PFBHA derivatives according to EPA Methods 556 and 556.1 “Determination of Carbonyl Compounds in Drinking Water”, we recommend a Supelco SLBTM-5ms capillary GC column (30 m x 0.25 mm I.D. x 0.25 μm df) as a primary column, and an Equity-1701 of the same dimensions as a confirmation column. These columns provide excellent resolution and fast, reproducible separations.

Recommended reading

PFBHA derivatives can be analyzed via LC with UV detection. A sensitive and selective method for common aldehydes and ketones in water and air is suggested in:

  1. Synthesis of the O-(2,3,4,5,6-Pentafluorobenzyl)Hydroxylamine Oximes of Selected Carbonyl Compounds and Their Determination by Liquid Chromatography with Ultraviolet Detection. K. Wiesenthal, A. Jehlar, S.S. Que Hee; Journal of AOAC International 2000, 83, 859.
  2. The combination of SPME (solid phase microextraction) and PFBHA derivatization in environmental monitoring can be used for a large number of compounds. In most cases, on-fibre derivatization has been used. See the following references:

  3. Formation and reaction of hydroxycarbonyls from the reaction of OH radicals with 1,3-butadiene and isoprene. J. Baker, J. Arey, R. Atkinson; Environ. Sci. Technol. 2005, 39, 4091-4099.
  4. Comparison of extraction techniques for GC determination of volatile carbonyl compounds in alcohols. W. Wardencki, J. Namiesnik, J. Orlita; Fresenius‘ J. Anal Chem. 2001, 369, 661-665.
  5. Determination of aldehydes in drinking water using penta fluorobenzylhydroxylamine derivatization and solid-phase microextraction. F. Ventura, B. Cancho, M. T. Galceran, Journal of Chromatography A 2002, 943, 1-13.
  6. Sampling and Determination of Formaldehyde Using SPME with On-Fiber Derivatization. P. Martos, J. Pawliszyn; Anal. Chem. 1998, 70, 2311-2320.
  7. Field Sampling and Determination of Formaldehyde in Indoor Air with SPME and On-Fiber Derivatization. J. Koziel, J. Noah, J. Pawliszyn, Environ. Sci. Technol. 2001, 35, 1481- 1486.
  8. Gas chromatographic determination of glutaraldehyde in the workplace atmosphere after derivatization with O- (2,3,4,5,6-pentafluorobenzyl)hydroxylamine on a solid-phase microextraction fibre. G. Pieraccini, G. Bartolucci; P. Boccalon, S. Dugheri, L. Focardi, M. Pacenti, Journal of Chromatography A 2002, 955, 117-124.
  9. Time-weighted average sampling of airborne n-valeraldehyde by a solidphase microextraction device. S.-W. Tsai, T.-A. Chang, Journal of Chromatography A 2002, 954, 191-198.

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