Application Notes: Reflectometry – Potassium in Plant Sap

Reflectometric determination after reaction with dipicrylamine

Reagents:

Cat. No. 116992 Reflectoquant® Potassium Test
Cat. No. 117246 Reflectometer RQflex® 20

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


Sample preparation:

Use an appropriate method to extract the sap from the plant to be analyzed (e.g. a juice extractor). Dilute the sap 1:10 with distilled water (1 part plant sap to 9 parts water) and mix thoroughly.

green grass

Analysis:
Immerse both reaction zones of the test strip in the diluted sample solution (15 - 30 ºC) for approx. 2 seconds. Allow excess liquid to run off via the long edge of the strip on to an absorbent paper towel. Press the reflectometer START button and at the same time place the test strip in the mini-test tube containing reagent K-1.

After the end of the waiting time (60 seconds), immediately remove the test strip, allow excess liquid to run off via the long edge of the strip on to an absorbent paper towel and then measure the strip in the reflectometer. The value [g/l] will be stored automatically. (Please refer to the RQflex® operating instructions and the package insert of the Reflectoquant® Potassium Test.)


Calculation:

Potassium content [g/l] = Measured value [g/l] x 10


Results - comparison with enzymatic method:

Sample Reflectoquant® [g/l]
Sap of beet leaves 6.9
Sap of maize leaves 4.0

 Materials

     
Related Links