The common methods for the personal monitoring of the exposure of workers to aldehydes in workplace air uses sampling through solids or liquids where the aldehydes are chemically converted to less reactive compounds which are then determined in the laboratory. The most widely used reagent is 2,4-dinitrophenylhydrazine (DNPH) which reacts with aldehydes to form hydrazones which are then determined by HPLC. It is difficult for laboratories to check if they meet the planned CEN requirement of 30 % overall accuracy; no quality assurance schemes or reference materials exist.
Intercomparisons will therefore be organised in which solutions of hydrazones, and impregnated filters containing the reaction products of formaldehyde, will be distributed. Reference materials will be certified (simulated sampling solutions, simulated sampling filters for formaldehyde, and pure substances). A type of diffusive samplers, which is already validated for formaldehyde, will be validated for other aldehydes as well. The analytes studied will be: formaldehyde, acetaldehyde, acrolein and glutaraldehyde (and acetone which is a common interferent).
Feasibility study (preparation of pure and homogeneous batches; study of stability upon long term storage) in progress.
Funding SchemeCSC - Cost-sharing contracts
TW16 7LN Sunbury On Thames
NG1 4BU Nottingham