Application
It is widely used to detect various
types of food in the levels of sulfur
dioxide or sulfites
Test
principle
The sulfur dioxide produced of food in
sulfur dioxide fumigation is a strong
reducing agent, bleaching can play, the
role of fresh food, make food surface
colors appear bright white, bright.
During the fumigate process, the residue
of sulfur will produce generate sulfite,
sulfite-focus, low-sulfite, etc. when
meet the high temperature. These salts
also have advantage of bleaching,
oxidation, corrosion and so on. However,
sulfur dioxide and sulfites, etc. will
destroy vitamin B1, affecting growth and
development, susceptibility to multiple
neuritis, bone marrow atrophy and other
symptoms, they have chronic toxicity.
Long-term eating can cause intestinal
tract function disorder, liver damage,
and serious harm to the body's digestive
system. Sulfite also triggers bronchial
spasms, trigger asthma. Therefore,
strict control of food such as sulfur
dioxide and sulfite content are
important word of the management table
pollution, protect the health of
consumers interests.
Specification: 100 times
Storage: normal temperature, avoid the
sunlight
Packing: 1.Two bottles of test solution
A
2. One bottle of test solution B
Period of validity: 6 months
Usage
1. Use the balance and weighed
1g sample cut into small pieces as
possible, then put into the sample cup,
and scale plastic straw adding 10ml
distilled water or purified water, lay
up for 10 minutes, during this period,
which the straw stirring or shaking can
be used to speed up the extraction, The
supernatant fluid is the sample liquid.
2. Dropping 2 drops of test solution A
to the multihole of Colorimetric tubes,
1 drop of test solution B, blending
enough. Then add 0.5ml (12 drops)
extracted sample solution, stir or
shake. Lay up for 2 minutes to observe
the color change and compare with the
color card.
Results
judgment
After 2 minutes to observe the depth of
color in the holes, if the color of the
sample solution deep than the color of
standard working solution, indicating
that the sample of sulfur dioxide or
sulfurous acid salt content may exceed
100mg / kg, and color is darker,
indicating that the sample of sulfur
dioxide or sulfurous acid salt content
higher. Compare with the standard color
card can be obtained the information
whether the sulfur dioxide or sulfurous
acid salt exceeded or not.
Announcement
1. When detecting, the test liquid A and
test solution B should be mixed in the
colorimetric cylinder, and then added to
the sample liquid. Solution adding turn
can not be reversed. To detect liquid
mixed with the sample solution
(preferably mixing blending), otherwise
test results may not reproduce or even
produce false negative results.
2. Reagents should be closed after use,
should be stored in the refrigerator or
a cool dry place away from light.
3. All experiments water should use
distilled water or purified water.
4. After each use, rinse lab ware for
more than three times, then washed with
distilled water or pure dry spare.
