Calculadora de Asimetría de Pico Gratis
Calcula el factor de asimetría de picos cromatográficos para evaluar la calidad de la separación.
Asymmetry Factor (As)
1.200
Asymmetry Factor (As) vs Back Half-Width at 10% Height (B)
Fórmula
## Peak Asymmetry and Tailing Factor Peak shape is a critical quality attribute in chromatography. Asymmetric peaks indicate column problems or unwanted secondary interactions. ### Formulas **Asymmetry Factor: As = B / A** (measured at 10% height) **USP Tailing Factor: Tf = (A + B) / (2A)** (measured at 5% height, but often approximated at 10%) - As = 1: perfectly symmetric - As > 1: tailing (common with silanol interactions) - As < 1: fronting (often from column overload)
Ejemplo Resuelto
A peak with front half-width A = 5 mm and back half-width B = 6 mm at 10% height.
- 01As = 6 / 5 = 1.200
- 02Tf = (5 + 6) / (2 × 5) = 11 / 10 = 1.100
- 03Slight tailing (acceptable; As < 1.5 is typically OK)
Preguntas Frecuentes
What asymmetry values are acceptable?
Typically As between 0.8 and 1.5. USP requires Tf <= 2.0 for most methods. Values outside 0.8-1.2 suggest column or method issues that should be investigated.
What causes peak tailing?
Secondary interactions with free silanols (for reversed-phase), extra-column dead volumes, column degradation, and chemical equilibria (e.g., acid-base) at the analyte concentration. Adding buffer or using end-capped columns helps.
What causes peak fronting?
Column overload (too much sample injected), very strong solute-stationary phase interactions at high concentrations, or a thermodynamically unfavorable isotherm shape.
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