Division 8 Procedure (used for the validated method)

1. 8.2.1.

   Using a four decimal place balance (6.2), weigh an appropriate sealed weighing vessel and record the weight.

2. 8.2.2.

   Pipette 9 ml 400 ml/l ethanol solution (5.13) into the vessel and record the weight.

3. 8.2.3.

   Add 1 ml of standard solution E (5.14.5) and record the weight.

4. 8.2.4.

   Shake the test material vigorously (at least 20 inversions). Samples must be stored at less than 5 °C prior to analysis in order to minimise any volatile losses.

Inject standard solution C (5.14.3) to ensure that all of the analytes are separated with a minimum resolution of 1.3 (except 2-methylbutan-1-ol and 3-methylbutan-1-ol).

The calibration should be checked using the following procedure. Ensure that the response is linear by successively analysing in triplicate each of the linearity standard solutions (5.14.6) containing internal standard (IS). From the integrator peak areas or peak heights for each injection calculate the ratio R for each congener and plot a graph of R versus the concentration ratio of congener to internal standard (IS), C. A linear plot should be obtained, with a correlation coefficient of at least 0,99.

Inject standard solution C (5.14.3) and 2 QC standard solutions (5.14.7). Follow with unknown samples (prepared according to 8.1 and 8.2) inserting one QC standard every 10 samples to ensure analytical stability. Inject one standard solution C (5.14.3) after every 5 samples.