Eurachem/CITAC Guide (2007) “Measurement Uncertainty arising from Sampling” provides examples on estimating sampling uncertainty. The Example A1 on Nitrate in glasshouse grown lettuce shows a summary of the classical ANOVA results on the duplicate method in the MU estimation without detailed calculations.
The 2007 NORDTEST Technical Report TR604 “Uncertainty from Sampling” gives examples on how to use relative range statistics to evaluate the double split design method which is similar to the duplicate method suggested in Eurachem.
We have used an Excel spreadsheet to verify the Eurachem’s results using the NORDTEST approach and found them satisfactory. The Two-Way ANOVA by the Excel Analytical Tool also shows similar results, but we have to combine the sum of squares of between-duplicate samples and sum of squares of interaction.