Division 9 Calculation
United Kingdom
An automated system of data handling can be used, provided the data can be checked using the principles described in the method below.
Measure either peak areas or peak heights for congener and internal standard peaks.
- 9.1.
Response factor calculation.
From the chromatogram of the injection of standard solution C (5.14.3), calculate response factors for each congener using equation (1).
where:
ISInternal Standard
concentration of congener in solution C (5.14.3)
concentration of internal standard in solution C (5.14.3).
- 9.1.2.
Sample analysis
Using equation (2) below, calculate the concentration of each congener in the samples.
where:
MSAMPLEweight of sample (8.1.2);
weight of internal standard (8.1.3);
concentration of internal standard in solution E (5.14.5);
response factor calculated using equation 1.
- 9.1.3.
Quality control standard solution analysis
Using equation (3) below, calculate the percentage recovery of the target value for each congener in the quality control standards (5.14.7):
The concentration of the analyte in the QC standard is calculated using equations (1) and (2) above.
- 9.2.
Final presentation of results
Results are converted from μ/g to g per 100 litres absolute alcohol for samples using equation (4):
where
ρdensity in kg/m3.
Results are quoted to 3 significant figures and a maximum of one decimal place e.g. 11,4 g per 100 l absolute alcohol.
