“…A microbore separation of 2,4-dintrophenylhydrazone (DNPH) (Aldrich Chemical Co., Milwaukee, WI) derivatives of aldehydes was included in this study to demonstrate the utility of the multiwavelength PSD-based absorbance detector with flowing liquid systems. The HPLC system consisted of a syringe pump (ISCO, LC-250, Lincoln, NE) coupled to a 0.5-mL injection valve (Rheodyne, 7125, Cotati, CA) and on to a 1 mm X 250 mm, 5 Mm, C18 column (Alltech, Abosbosphere HS, Deerfield, EL) which was connected to the UV-vis flow cell previously described. The eluent used for the reversed-phase separation of the aldehyde-DNPH derivatives consisted of 80% methanol (EM Science, Omnisolv, Cherry Hill, NJ) and 20% water (EM Science, Omnisolv, Cherry Hill, NJ) at a volumetric flow rate of 50 µ ,/ and a typical column pressure drop of 1580 psi.…”