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| DETERMINATION OF CHLORIDE IN AQUEOUS SOLUTION WITH
FOODLAB |
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With the
analysis of the chlorides, it is possible to quantify the concentration of
salt in the liquids for processing or preserving milk by-products
(mozzarella, ricotta ...).
With the FoodLab system it is possible to determine the concentration of
chlorides in just a few minutes, without any previous treatment of the
sample.
Furthermore, the FoodLab analyzer, using previously dispensed,
non-returnable (disposable) cuvettes, requires neither specialized personnel
nor reagent preparation.
The method's reliability and precision are guaranteed by a calibration
system that makes it possible to align the instrument using standard
solutions.
The FoodLab system was tested through recovery tests. |
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| MATERIALS
AND CORRELATION METHODS |
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The FoodLab
method is based on a colorimetric reaction in which the chloride ions react
with the mercuric thiocyanate and with the Fe (II), forming an orange
complex whose intensity, measured at 505 nm, is directly proportional to its
concentration in the sample. The FoodLab instrument is capable of measuring
the intensity of the color, eliminating the interferences due to the
turbidity of the liquids.
Recovery tests were carried out on a sample of liquid for preserving
mozzarella (aqueous solution): Sodium chloride in various concentrations was
added to 5 aliquots of aqueous solution, which were then tested using
FoodLab.
Furthermore, 5 repeatability tests were carried out for each
sample. |
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| RESULTS
AND DISCUSSION |
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| The FoodLab
system allows a practically total recovery of chlorides at the various
concentrations. The reference values and the tests carried out using the
FoodLab system are compared in Tab.1. The values are perfectly
comparable and the repeatability of the data is very good, as seen from the
standard deviation and from the VC computed for each sample. In Fig.
1, the regression line correlation coefficient (r = 0.997) confirms the
optimum agreement of the instrument with the reference method. |
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| Fig.1
- Correlation between FoodLab method and reference method |
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| Tab.1 - Repeatability tests with FoodLab
system |
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Ref
g/dL |
0,20 |
0,40 |
0,60 |
0,80 |
1,00 |
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0,19 |
0,39 |
0,61 |
0,84 |
0,97 |
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0,18 |
0,40 |
0,63 |
0,84 |
0,95 |
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0,18 |
0,41 |
0,64 |
0,79 |
0,98 |
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0,19 |
0,39 |
0,63 |
0,80 |
1,00 |
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MEAN |
0,19 |
0,40 |
0,62 |
0,82 |
0,98 |
SD |
0,01 |
0,01 |
0,01 |
0,02 |
0,02 |
CV,% |
6,4 |
2,1 |
1,8 |
2,8 |
2,0 |
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| SHORT
TABLE |
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Linearity |
Accuracy |
Repeat. |
R2 |
Sensitivity |
Total
analysis
time
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Test/hour |
5 g/dL |
±5% |
CV < 6% |
r > 0,99 |
0,01 g/dL |
5 - 8 min |
70 |
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| Foodlab¬ |
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» A new concept in
quality analysis of food.
Foodlab is a quick, reliable and practical system for chemical tests on
olive oil, seed oils, alimentary fats, vegetable purées, milk, cheese
and other dairy products. |
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