Enter concentrations and peak areas. The tool performs linear regression, plots linearity, and calculates: LOD = 3.3 × σ / S, LOQ = 10 × σ / S.

LOD & LOQ by Method 3 (Statistical) σ from regression residuals Linearity graph with regression line
Sample Information & Stock Preparation
Enter organization details and stock dilution parameters.
Name Of Organisation
Product Name
Component Name
Potency (%)

Start with Stock-I (base stock with weight & dilution). You can rename stocks by editing the Stock Name column. Use "+ Add Stock" to add dilution steps. Each dilution can be created from any previous stock by selecting the parent stock from the dropdown. This allows multiple parallel dilutions from the same stock. Concentrations update automatically.

Test Preparation
Record test solution dilutions (no automatic calculations are performed).
Dilution-1 Dilution-2
Wt (mg) Dilution Conc (µg/mL) ml Taken Dilution Conc (µg/mL)
– µg/mL – µg/mL
Calibration Data (Levels & Areas)
Provide at least 3–5 non-zero levels with corresponding peak areas.
# Stock Source ml Taken Dilution Concentration
(µg/mL)
Peak Area-1
(arb. units)
Peak Area-2
(arb. units)
Average
(arb. units)
% Level
(vs test conc.)
Delete

Tip: Use the arrow keys to move between cells, just like in a spreadsheet. Concentrations are calculated automatically from the selected stock, ml taken, and dilution.

Results
Regression based on entered data. σ is calculated from residual standard deviation (Sy/x).
Slope (S)
area / conc
Intercept (b)
Residual SD (σ)
area
Correlation Coefficient (r)
LOD
mcg/mL
% of test conc.
LOQ
mcg/mL
% of test conc.

Note: LOD = 3.3 × σ / S   •   LOQ = 10 × σ / S   •   σ from residuals ≈ standard deviation of response (ICH Q2).

Linearity Graph
Scatter plot of concentration vs peak area with regression line overlay.