FluoroSELECT™ – Handheld Fluorometers and Kits for Field and Lab Application

By: Jens Boertz, Bernhard Schönenberger, Roland Meier, Analytix 2014, Issue 3

Application Test – Ascorbic Acid in Milk

The FluoroSELECT™ product line combines portable, low cost, single-channel fluorometers with suitable kits for a wide range of applications. FluoroSELECT stands for highly sensitive and easy-to-use workflow solutions for determination of a growing selection of analytes, both in the field or in the lab.

Each kit contains all documents, reagents and standards needed to perform the analysis, together with the corresponding fluorometer.

The data from the application test for the FluoroSELECT ascorbic-acid kit using a FluoroSELECT Single Channel Fluorometer are presented here.

Linearity: The FluoroSELECT ascorbic-acid kit shows a linear response over two orders of magnitude (1–100 μmol/L ascorbic acid, Figure 1) and also demonstrates linearity in the lower concentration range (1–10 μmol/L, Figure 2).


Stability: In order to check stability of the instrument and robustness of the kit, replicates of the same sample were measured during a three hour period, with and without repeating the calibration. These measurements indicated comparable results.

Measurement of ultra-heat treated milk: The milk analyzed was common ultra-heat treated (UHT) milk from a Swiss supermarket. The expected value was approx. 42 μmol/L, the value measured 44 μmol/L. Assuming an expanded uncertainty of at least 5–10% for the measurement by using the FluoroSELECT kit, the concentrations matched.


Summary
FluoroSELECT ascorbic-acid kit is an easy-to-handle and robust method to quantifi y ascorbic acid in a linear range of 1–100 μmol/L in an aqueous solution. An application test was done by quantifying ascorbic acid in UHT milk. The measured value was in agreement with the theoretical value; therefore, the kit has the potential to be used for ascorbic-acid quantifi cation in the food industry.





Materials
     

FluoroSELECT is a trademark of Sigma-Aldrich Production GmbH

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