Calculate Peak Resolution

Calculates the resolution between two chromatographic peaks using the USP or EP formula.

Usage

measure_sec_resolution(
  retention_1,
  retention_2,
  width_1,
  width_2,
  width_type = c("baseline", "half_height", "tangent"),
  method = c("usp", "ep")
)

Arguments

retention_1

Retention time of the first peak (earlier eluting).

retention_2

Retention time of the second peak (later eluting).

width_1

Peak width of the first peak. See width_type for units.

width_2

Peak width of the second peak.

width_type

Type of peak width measurement:

• "baseline" (default): Width at baseline (Wb)

• "half_height": Width at half height (W0.5h)

• "tangent": Width from tangent lines at inflection points

method

Resolution formula to use:

• "usp" (default): Rs = 2(t2 - t1) / (w1 + w2)

• "ep": Rs = 1.18(t2 - t1) / (w1_0.5h + w2_0.5h)

Value

Numeric resolution value. Rs > 1.5 indicates baseline separation.

Details

Resolution quantifies the degree of separation between adjacent peaks:

USP Formula (baseline width): $$R_s = \frac{2(t_2 - t_1)}{W_{b1} + W_{b2}}$$

EP Formula (half-height width): $$R_s = \frac{1.18(t_2 - t_1)}{W_{0.5h,1} + W_{0.5h,2}}$$

Interpretation:

• Rs < 1.0: Peaks overlap significantly

• Rs = 1.0: ~94% separation (4 sigma)

• Rs = 1.5: Baseline separation (~99.7%)

• Rs > 2.0: Complete separation with gap

See also

Other sec-qc: measure_sec_asymmetry(), measure_sec_column_performance(), measure_sec_plate_count(), measure_sec_recovery(), measure_sec_suitability()

Examples

# Calculate resolution between monomer and dimer
measure_sec_resolution(
  retention_1 = 8.2,   # dimer (elutes first in SEC)
  retention_2 = 9.5,   # monomer
  width_1 = 0.4,
  width_2 = 0.5
)
#> [1] 2.888889