Application Notes: Reflectometry – Iron in Red and White Wine

Reflectometric determination after reaction with Ferrospectral®

Reagents

Catalog No. 116982 Reflectoquant® Iron Test
Catalog No. 117246 Reflectometer RQflex® 20
Catalog No. 100456 Nitric acid 65 %
Catalog No. 100630 Nitric acid 10 mol/l, Titripur®
Catalog No. 1831 Ascorbic Acid, e.g. Calbiochem®

This application note pertains to RQflex® 20 and all discontinued instruments (RQflex® 10, RQflex® plus)

The quantity, type, and reaction time of the Divergan used are of major influence in the decolorizing process. We recommend the following procedure.

Sample preparation

Dilute the wine 1+1 with distilled water.

Iron in red and white wine

Analysis

Press the reflectometer START button and simultaneously dip the test strip into the sample (5 - 40 °C) for approx. 2 seconds, ensuring that both reaction zones are immersed. Allow excess liquid to run off via the long edge of the strip on to an absorbent paper towel.

Wait 15 seconds and then measure the strip in the reflectometer. The value [mg/l] will be stored automatically. (Please refer to the RQflex® operating instructions and the package insert of the Reflectoquant® Iron Test.)

Notes

The test determines only iron that is not in complex form. If complexed iron has to be analyzed, too, digestion has to be carried out.

Calculation

 

Results – comparison with photometric method:

Sample Reflectoquant® [mg/l] Photometry [mg/l]
1 1,6 1,6
2 6,6 6,4
3 5,2 5,4

Materials