EM Quant® Ascorbic Acid Test, Catalog No. 10023
Test strips for the detection and
semi-quantitative determination of ascorbic acid
The ascorbic acid test can be used to measure
natural ascorbic acid (vitamin C) in foods such as fruit and vegetable
juices, soft drinks, beer and wine, and also to check how much ascorbic
acid has been added to meat products and other food and drinks as a
preservative or antioxidant.
It can also be used to measure vitamin C loss in
foods following storage, processing or cooking.
Direct determinations can be conducted in liquid
samples as well as on the freshly cut surfaces of fruit, potatoes or
With its large number of applications in the
food industry, the test can be used to simplify in-process controls,
often replacing or at least reducing the need for costly laboratory
Principle of the Method
The color reaction is based on the reduction of
yellow phosphomolybdate complex to molybdenum blue by ascorbic acid.
0 - 50 - 100 - 200 - 300 - 500 - 700 - 1000 - 2000mg/l ascorbic acid
- Immerse the test strip in the solution for 1
second, so that the reaction zone is thoroughly moistened.
- Remove the test strip, gently shake off
excess liquid, wait 10 seconds and compare the reaction zone with
the color scale.
Strongly colored liquids, e.g. red currant juice, obscure the color reaction.
Check decoloring agents, if used, to discover whether these oxidize ascorbic
acid to dehydroascorbic acid, in which case it no longer shows up in the
test. Activated charcoal, in particular, may have this effect. Good results
can be achieved with Avicel™ cellulose powder.
EM Quant® blank strips, Catalog Number 11860, may
prove useful when the solution is not too strongly colored. When dipped
in the colored solution, the paper takes on a color which is then taken
as the zero value for subsequent comparisons.
Since the basis of the test is a reduction
reaction, reducing agents similar to ascorbic acid may yield "false-positives."
The strips cannot be used for testing urine because uric acid interferes.
Dissolve 0.10g of ascorbic acid in 100ml of distilled water
10023 EM Quant® Pack of 100 test strips