Proficiency testing schemes in Europe have shown that there was a need to improve the quality of the measurements to assess exposure to harmful chemicals in air at the workplace. Efforts were required to provide calibrants and CRMs for quality control.
Aldehydes are important industrial chemicals and are present in a wide range of industries and other applications. For monitoring of aldehydes in air, the most frequently used technique is based on derivatization with 2,4-dinitrophenylhydrazine (DNPH) and determination of the resulting hydrazones by high performance liquid chromatography.
The project aimed at the preparation and certification of three types of reference materials:
(a) glass fibre filters simulating those obtained after the sampling of formaldehyde;
(b) ampoules containing solutions simulating those obtained after the sampling of formaldehyde, acetaldehyde, acrolein and acetone;
(c) five pure hydrazones, i.e. the DNPH-derivatives of formaldehyde, acetaldehyde, acrolein, acetone and glutaraldehyde.
For types (a) and (b), reagent blanks were also required.
9 reference materials have been certified and are available from IRMM:
CRM 546: formaldehyde-DNPH (pure compound)
CRM 547: acetaldehyde-DNPH (pure compound)
CRM 548: acrolein-DNPH (pure compound)
CRM 549: acetone-DNPH (pure compound)
CRM 550: glutaraldehyde-DNPH (pure compound)
CRM 551: solution of formaldehyde-DNPH, acetaldehyde-DNPH, acrolein-DNPH, acetone-DNPH, glutaraldehyde-DNPH and an excess of DNPH in acetonitrile
CRM 552: solution of DNPH in acetonitrile (reagents blank going with CRM 551)
CRM 553: formaldehyde-DNPH on glass fibre filter impregnated with DNPH
CRM 554: glass fibre filter impregnated with DNPH (reagents blank going with CRM 553)
The work done under this contract consisted essentially of the preparation, homogeneity testing and stability testing of the materials and the distribution of samples. This contract ran in conjunction with a contract from the BCR programme covering the actual certification tasks.