To identify the Kdo, the sample was then treated for the reduction of the carboxymethyl groups with sodium boro deuteride NaBD 4, mildly hydrolyzed (0.1 M trifluoroacetic acid TFA, 100 °C, 30 min) to cleave ketosidic linkages, followed by a reduction (NaBD 4) of hemiketal group.
Source: wiktionary