Successful GERSTEL participation in DGF Round Robin on Determination of 3-MCPD-, 2-MCPD- and Glycidol-esters in edible oil and fat.
The Deutsche Gesellschaft für Fettwissenschaft (DGF), which roughly translates to German Society for the Science of Fat, organizes extensive international round robin tests of analysis methods for edible oils and fats.
GERSTEL recently participated in such a round robin test organized by the DGF with a large number of international participants.
Accredited laboratories must regularly take part in such round robin tests in order to retain their accreditation.
GERSTEL relied on a fully automated solution for the determination of 2- and 3-MCPD-esters as well as glycidol-esters in accordance with the ISO 18363-1, AOCS Cd 29c-13, and DGF C-VI 18 (10) methods.
After eliminating outliers, the results from the laboratories are used to calculate and establish an “assigned value” as “true” analysis result for the sample.
The z-score is a measure of the agreement of the individual analysis result value with the assigned value. The closer the z-score is to 0, the better the agreement. Z-scores up to +/-2 are acceptable, customers often specify desired z-scores of +/-1.5 as KPIs, z-scores between -1 and 1 are very good. GERSTEL was in the range between -1 and 1 for all samples and analysis parameters.
The DGF score finally summarizes the z-scores. If the z-score is between -1 and 1, the participant achieves the maximum value of 2 points in the DGF score. GERSTEL achieved the maximum DGF score of 2 for all samples and analysis parameters.
The results achieved by GERSTEL are presented in the following table:
| 3-MCPD- Esters |
Assigned value [µg/kg] |
Median [µg/kg] |
Standard deviation for proficiency assessment [µg/kg] | GERSTEL value [µg/kg] | GERSTEL z score | GERSTEL DGF score |
|---|---|---|---|---|---|---|
| Sample A | 75,8 | 74,5 | 34,3 | 97,0 | 0,62 | 2 |
| Sample B | No evaluation. inhomogeneous distributionof results |
No evaluation. inhomogeneous distribution of results | No evaluation. inhomogeneous distribution of results |
10,0 | - | - |
| Sample C | 601,2 | 600,5 | 68,0 | 665,5 | 0,95 | 2 |
| Glycidyl - Esters |
Assigned value [µg/kg] |
Median [µg/kg] |
Standard deviation for proficiency assessment [µg/kg] |
GERSTEL value [µg/kg] | GERSTEL z score | GERSTEL DGF score |
|---|---|---|---|---|---|---|
| Sample A | 115,6 | 119,5 | 35,0 | 112,5 | -009 | 2 |
| Sample B | 38,7 | 34,5 | 30,0 | 26,0 | -0,42 | 2 |
| Sample C | 85,1 | 78,5 | 58,1 | 106,0 | 0,36 | 2 |
| 2-MCPD- Esters |
Assigned value [µg/kg] |
Median [µg/kg] |
Standard deviation for proficiency assessment [µg/kg] | GERSTEL value [µg/kg] | GERSTEL z score | GERSTEL DGF score |
|---|---|---|---|---|---|---|
| Sample A | 28.8 | 30.4 | 16.6 | 32.5 | 0.22 | 2 |
| Sample B | 5.8 | 6.5 | 8.7 | 3.0 | -0.32 | 2 |
| Sample C | 266.8 | 267.5 | 55.2 | 293.0 | 0.49 | 2 |
GERSTEL achieved the maximum DGF-score using the fully automated analysis method according to ISO 18363-1, AOCS Cd 29c-13, DGF C-VI 18 (10).
For further information about the results and the methods used, please contact GERSTEL at the following email address: Info@gerstel.de.