CHROMATOGRAPHIC RESOLUTION — Impact of k, α and N
INPUT PARAMETERS
OUTPUT — RESOLUTION
| Quantity | Value | Unit |
|---|
| Retention factor (k2) | — | — |
| Retention time of peak 1 (tR1) | — | min |
| Retention time of peak 2 (tR2) | — | min |
| Peak width (w) | — | min |
| Resolution (RS) | — | — |
| Separation quality | — | — |
The fundamental resolution equation: RS = (√N/4) · [(α−1)/α] · [k/(1+k)]
IMPACT OF k, α AND N ON RESOLUTION
VAN DEEMTER EQUATION — Kinetic Performance
COLUMN PARAMETERS
OUTPUT — KINETIC PERFORMANCE
| Quantity | Value | Unit |
|---|
| Column dead time (t0) | — | min |
| Linear velocity (u) | — | mm/s |
| Reduced velocity (ν) | — | — |
| Optimal linear velocity (uopt) | — | mm/s |
| Plate number (N) | — | plates |
| Plate height (H) | — | µm |
| Minimum plate height (Hmin) | — | µm |
| Pressure drop (ΔP) | — | bar |
| Maximum flow rate (ΔP=1000 bar) | — | mL/min |
H vs u VAN DEEMTER CURVE
N vs F PLATE NUMBER VS FLOW RATE
LOG P — Retention in Reversed-Phase LC
INPUT PARAMETERS
OUTPUT — RETENTION
| Quantity | Value | Unit |
|---|
| S parameter (slope) | — | — |
| log kw (100% water) | — | — |
| Retention factor (k) | — | — |
| Retention time (tR) | — | min |
| Elution strength evaluation | — | — |
Snyder-Dolan LSS model: log k = log kw − S·φ
log kw ≈ 0.94 + 0.74·log P S ≈ 0.25·log kw + 1.5
LOG P APPLICABILITY RANGE
RETENTION MAP — log k vs % METHANOL
PKA — Mobile Phase pH and Analyte Ionization
INPUT PARAMETERS
OUTPUT — IONIZATION & RETENTION
| Quantity | Value | Unit |
|---|
| % Ionized | — | % |
| % Neutral | — | % |
| Retention factor (k) | — | — |
| Retention time (tR) | — | min |
| Ionization state | — | — |
% IONIZATION vs pH
RETENTION FACTOR vs pH
TEMPERATURE — Thermodynamic & Kinetic Effects
INPUT PARAMETERS
OUTPUT
| Quantity | Value | Unit |
|---|
| Retention factor k (at T) | — | — |
| Diffusion coefficient (Dm) | — | cm²/s ×10⁻⁵ |
| Mobile phase viscosity (η) | — | cP |
| Plate number N | — | plates |
| Pressure drop ΔP | — | bar |
VAN'T HOFF PLOT — log k vs 1/T
PRESSURE & EFFICIENCY vs TEMPERATURE
ISOCRATIC MODE — LSS Retention Modeling
INPUT PARAMETERS
COMPOUNDS (log P & S)
SEPARATION QUALITY
| Metric | Value |
|---|
| Dead time t0 (min) | — |
| Last peak tR (min) | — |
| Minimum resolution RS,min | — |
| Critical pair | — |
RS,min vs % METHANOL (METHOD OPTIMIZATION)
GRADIENT MODE — Linear Solvent Gradient Elution
COLUMN & INSTRUMENT
GRADIENT PROFILE
PERFORMANCE
| t0 (min) | — |
| Dwell time (min) | — |
| Gradient steepness b | — |
| Peak capacity nc | — |
| Cycle time (min) | — |
| RS,min | — |
INJECTED VOLUME — Sensitivity vs Band Broadening
COLUMN & INJECTION
OUTPUT
| Quantity | Value | Unit |
|---|
| Intrinsic plate number (N) | — | plates |
| Column volume (Vcol) | — | µL |
| Peak volume (VR) | — | µL |
| Max recommended Vinj | — | µL |
| Observed plates (Nobs) | — | plates |
| Efficiency loss | — | % |
| Verdict | — | — |
OBSERVED PLATES vs INJECTION VOLUME
TUBING — Extra-Column Band Broadening & Pressure Drop
CONNECTING TUBING PARAMETERS
OUTPUT — BAND BROADENING & PRESSURE
| Quantity | Value | Unit |
|---|
| Tubing volume (Vtub) | — | µL |
| Linear velocity in tubing (utub) | — | mm/s |
| Tubing variance σ²tub | — | µL² |
| Column variance σ²col | — | µL² |
| Nobs after tubing | — | plates |
| Efficiency loss from tubing | — | % |
| Tubing pressure drop (ΔPtub) | — | bar |
Nobs vs TUBING DIAMETER
EXTRA-COLUMN VARIANCE CONTRIBUTION
MOLECULAR WEIGHT — Thermodynamic & Kinetic Impacts
INPUT PARAMETERS
OUTPUT
| Quantity | Value | Unit |
|---|
| Diffusion coefficient Dm | — | ×10⁻⁵ cm²/s |
| S parameter | — | — |
| log kw | — | — |
| Retention factor k | — | — |
| Retention time tR | — | min |
| Opt. linear velocity uopt | — | mm/s |
Dm vs MOLECULAR WEIGHT
OPTIMAL u & k vs MW