Analysis was performed with a Waters 2795 Alliance HT,
equipped with autosampler and Waters 996 Photodiode Array
detector. The data were collected and analysed with the System
Millennium software. GCE, GSE (both at 10 lg/ll) or AGE
(300 lg/ll) was added to a 5 ml aliquot of methanol. Ten microlitres
of GCE and GSE, and 1 ll of AGE were injected. Separation was
carried out by using Kromasil C18 column (150 43 mm; 5 lm).
The mobile phase consisted of water (solvent A) and acetonitrile
(solvent B) and was run at flow rate of 0.4 ml/min, with a gradient
of 20% B (2 min), with an increase to 60% B (28 min), and then with
a re-equilibration at 10% B (2 min). Diode array detection was used
to monitor the effluent at 254 nm.