Fig. 4.
Analyte recoveries after liquid-liquid extraction (a) and solid-phase extraction (b). Recoveries were calculated from triplicate HPLC analysis of three to five replicate extractions of 10 μmol L−1 standard solution of the respective UDP-sugars. The diagram shows arithmetic averages and relative standard deviations of all analyses performed; sample size in (a): N = 9 for UDP-Glc, UDP-Xyl, UDP-GalA, and UDP-GlcA, N = 15 for UDP-Ara and UDP-Gal, sample size in (b): N = 31 for UDP-Glc, N = 15 for UDP-Ara, UDP-Xyl, UDP-Gal, UDP-GlcA, UDP-GalA