Materials and Reagents
Product No. 173016 Spectroquant® UV/VIS Spectrophotometer Prove 100 or
Product No. 173017 Spectroquant® UV/VIS Spectrophotometer Prove 300 or
Product No. 173018 Spectroquant® UV/VIS Spectrophotometer Prove 600
Product No. 104718 Isooctane for spectroscopy Uvasol®
Product No. 114946 Rectangular cells 10 mm or
Product No. 100784 Rectangular cells quartz 10 mm
Volumetric flasks, class A, volume range 25 mL to 250 mL
Analytical balance 0.0001 g
Method and Measuring Range
Method No. 2523
10 – 7500 mg/kg ß-carotene
- 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.
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.
- 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.