Analytical Method: Determination of the carotene content of raw palm oil acc. to DIN EN ISO 17932:2011

Materials and reagents:
Cat. No. 173016  Spectroquant® UV/VIS Spectrophotometer Prove 100 or
Cat. No. 173017  Spectroquant® UV/VIS Spectrophotometer Prove 300 or
Cat. No. 173018  Spectroquant® UV/VIS Spectrophotometer Prove 600
Cat. No. 104718  Isooctane for spectroscopy Uvasol®
Cat. No. 114946  Rectangular cells 10 mm or
Cat. No. 100784  Rectangular cells quartz 10 mm
Volumetric flasks, class A, volume range 25 ml to 250 ml
Analytical balance 0.0001 g
Paper filters

Method and measuring range:
Method No. 2523
10 – 7500 mg/kg ß-carotene

Sample preparation:
Melt the sample at 60 - 70 °C and homogenize.
If conterminations are present, filter the sample over a fast filtering paper.


Weigh between 100.0 mg and 500.0 mg of sample, accurately weighed to 0.1 mg, into a volumetric flask.
The use of a 25-ml volumetric flask is recommended for samples with an anticipated con­tent of up to 750 mg/kg β-carotene. For samples with an anticipated content exceeding 750 mg/kg β-carotene, a volumetric flask with a greater volume (max. 250 ml) should be used.

Add a few millilitres of isooctane and dissolve the sample at room temperature. Subsequently make up the contents of the volumetric flask to the mark with isooctane and mix.
Filter turbid solutions over a paper filter.

Zero adjustment:
For each measurement series, a zero adjustment is required.
It is recommended to use the same cell for zero adjustment and for sample measurement.
The zeroing procedure for the measurement series is automatically prompted by the instrument.

For zero adjustment fill 10-mm rectangular cell with isooctane.
After prompting, place the rectangular cell filled with isooctane in the cell compartment, the zero adjustment is executed automatically.
Confirm the implementation of zero adjustment with "OK".
The zero adjustment is valid for the entire measurement series.

Measurement procedure:
Select method 2523 "Carotene (palm oil)" from method list.

Enter the weight in milligram, and confirm with "OK".
To enter the volume of the sample solution, tap the input field in the “Sample Solution” line, enter the volume in milliliters, and confirm with "OK".
Press "START" to reach the measuring mode.

Prior to the measurement of the first sample the system automatically prompts a zero adjustment (procedure see "Zero adjustment").

Transfer the sample solution into a 10-mm rectangular cell and place the rectangular cell into the cell compartment, the measurement is performed automatically.
Confirm measurement with "OK".
The ß-carotene content in mg/kg is shown in the display.

Press "START" to start the measurement procedure for the next sample. The system does not prompt a repeat of the zero adjustment.

According to DIN EN ISO 17932:2011 the method checks automatically if the measured absorption is in a range of 0.200 – 0.800 A. If the absorption is not in this range, a pop-up message appears: “Condition not met – Absorbance < 0.2” resp. “Condition not met – Absorbance > 0.8”.
In these cases, the sample preparation needs to be adjusted. Use an appropriate sample weight in a range of 100 – 500 mg and a volumetric flask in a range of 25 – 250 ml to achieve these absorption values.


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