Determination of Citric Acid in Soft Drinks
Citric acid can be added to soft drinks as an additive to regulate the acidity of the product. Its presence lowers the pH, creating an environment that is unfavorable to the growth of pathogenic microorganisms and thus helping to extend the shelf life of the product. Too low a content can compromise preservation, while excessive levels can alter the flavor.
Method
Sample treatment
Degas using the ultrasonic bath (code 222062) before taking the sample. It is necessary to dilute the sample with the appropriate dilution kit (*300386) before carrying out the analysis on the [2-10] g/L curve.
Principle of the test
Through an enzymatic reaction, citric acid is converted to oxaloacetate and then to malate which reacts with NADH to produce NAD+. The decrease in absorbance, measured at 366 nm (end-point), of the NADH solution is proportional to the amount of citric acid present in the sample.
Calibration curve
The calibration curve of the CDR DrinkLab system, carried out using HPLC as a reference method, confirmed excellent linearity of the system throughout the measurement range.
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Reagent test Kits
Code*301225: 10 tests
Measuring range
| Analyses | Measuring range | Resolution | Repeatability |
|---|---|---|---|
| Citric Acid [2-10] g/L | 2 - 10 g/L | 0.1 g/L | 0.4 g/L |
| Citric Acid [0.5-5.0] g/L | 0.5 - 5 g/L | 0.1 g/L | 0.1 g/L |
The perfect system for you
CDR DrinkLab
Complete analysis panel, supplied already configured
Up to 16 determinations simultaneously
Possibility of carrying out analyses of the same sample
Integrated printer
Full connections (LAN - USB - Bluetooth barcode/QR code reader)