Liquid chromatography analyses were carried out on an Alliance
HPLC 2695 system, controlled by an Empower Pro 2002 data station
(Waters, Milford, MA) and a fluorescence detector (Waters 474
Fluorescence Detector) was used for melatonin determination. A
reverse phase RP-18 Lichrospher Column (LiChroCART 250 4
(5 mm)) from Merck was used.