Methanol → L-Leucine

Solutions were injected onto an Ultrasphere ODS column (5 μm, 250×4.6 mm.i.d., Rainin Instruments (Woburn, MA., U.S.A.)) attached to an Hypersil ODS guard column (5 μm, 50×4.6 mm.i.d., Shandon Southern (Sewickley, Pa.)) packed in our laboratory. The elution was performed using isocratic mode for the pH-rate profile study using a mobile phase consisting of 25% acetonitrile and 75% phospate buffer (0.05M, pH 6.8). The gradient was done by the application of a solvent gradient provided by two Altex pumps (Model 110A, Beckman Instruments, Berkeley, Calif.). Solvent A was 10% THF with 90% phosphate buffer (0.05M, pH 6.8), and solvent B was 55% acetonitrile was 10% methanol and 35% phosphate buffer (0.05M, pH 6.8). The eluant was monitored using a Model FS 970 LC fluorometer (Schoeffel Instruments) equipped with a Corning 7-54 primary filter and a 470 nm cutoff secondary filter. The excitation wavelength was set to 420 nm. The cell volume was 5 μl. The range was set at 1.0 μA., and the time constant at 0.5 sec. Quantification was accomplished with an Omniscribe recorder by manual peak height measurements. A linear gradient profile was employed from 0 to 60% B over the period of 60 minutes followed by a steep increase to 100% B over a period of 5 minutes. At the end of the run, the eluant was returned to 100% A over a period of 5 minuts. The gradient was controlled by a SLIC 1400 (Systec. New Brighton, Minn.). A total flow rate of 1.0 ml/min was used throughout.

1. customequipped with a Corning 7-54
2. filtrationprimary filter
3. customwas employed from 0 to 60% B over the period of 60 minutes
4. temperaturea steep increase to 100% B over a period of 5 minutes
5. waitAt the end of the run, the eluant was returned to 100% A over a period of 5 minuts

ORD record

ord-645a7d30f8fa41668594710dc5467973

Source dataset

uspto-grants-1990_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04910314