DETERMINATION OF CARBONYL-COMPOUNDS IN THE LOW PPB-RANGE BY CAPILLARY ELECTROPHORESIS

A new method for analysing carbonyls (aldehydes and ketones) by capillary electrophoresis (CE) is described. The carbonyls are derivatized with DNSH [5-(dimethylamino)naphthalene-1-sulphonehydrazide, Dansylhydrazine] to form detectable compounds and also to form negative charged molecules (buffer pH 7.1). Detection is carried out by UV or, alternatively, by fluorescence. Eight carbonyls are separated in less than 8 min. Electrokinetic injection is made by using a new experimental set-up. The electroendosmatic flow (EOF) is reversed during sample injection by pressure. Results are compared with HPLC-analysis as the most common method in carbonyl analysis.