Headspace gas-chromatographic determination of formaldehyde in urine

A method is proposed for determining formaldehyde by headspace gas chromatography using an o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) derivatizing agent. Formaldehyde in urine was derivatized to o-(pentafluorobenzyl)oxime and extracted by heating an urine sample with PFBHA in a sealed vial. Gas-chromatographic analysis of the headspace was performed in the temperature-programmed mode using an HP-5 capillary column with a flame ionization detector. The limit of detection is 3.5 mu g/L. The accuracy of the procedure, equivalent to an extended relative uncertainty, does not exceed 21%. The examination of the procedure using urine samples of the population of the Irkutsk region has shown that the regional reference levels of formaldehyde concentration are in the range 44-83 mu g/L.