UV-Vis Double Beam Spectrophotometer — Optical Path
Source → Monochromator → Rotating Sector Mirror (chopper) → Sample / Reference → Detectors → Recorder
UV beam (D₂ lamp)
Visible beam (W lamp)
Sample-path beam
Reference-path beam
Recorded absorbance trace
Joy to the World
GC Solvents — Polarity Vs Boiling Point
GC Capillary Column
Optimum Injection Volume Calculator
Unit: metre (m)
Unit: mm
Unit: µm
Recommended Starting Volume
— µL
Suggested Practical Range
— µL
Column Internal Volume
— µL
Calculation Basis
Column internal volume is calculated using:
V = π × (ID / 2)² × L
The recommended injection volume uses an empirical capillary-GC starting rule based primarily on column internal diameter, with mild corrections for film thickness and column length.
Typical starting points:
• 0.10 mm ID → approximately 0.15 µL
• 0.18 mm ID → approximately 0.30 µL
• 0.25 mm ID → approximately 0.50 µL
• 0.32 mm ID → approximately 1.00 µL
• 0.53 mm ID → approximately 2.00 µL
Column internal volume is calculated using:
V = π × (ID / 2)² × L
The recommended injection volume uses an empirical capillary-GC starting rule based primarily on column internal diameter, with mild corrections for film thickness and column length.
Typical starting points:
• 0.10 mm ID → approximately 0.15 µL
• 0.18 mm ID → approximately 0.30 µL
• 0.25 mm ID → approximately 0.50 µL
• 0.32 mm ID → approximately 1.00 µL
• 0.53 mm ID → approximately 2.00 µL
Important:Column length, internal diameter and film thickness
alone cannot uniquely determine the true optimum GC
injection volume.
Actual injection volume depends on injection mode (split/splitless), split ratio, inlet liner, inlet temperature, solvent, analyte concentration, detector sensitivity, stationary-phase capacity and the required peak response.
Therefore, this calculator should be used as a method-development starting point, followed by experimental optimization.
Actual injection volume depends on injection mode (split/splitless), split ratio, inlet liner, inlet temperature, solvent, analyte concentration, detector sensitivity, stationary-phase capacity and the required peak response.
Therefore, this calculator should be used as a method-development starting point, followed by experimental optimization.
