MXMF.Users.Handbook.V2.20.doc
LIT:MXUHB April 2003
6
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No.
Q
A
1
What is the difference between MX/MF
and Karl Fischer type analyzer?
1. MX/MF is a heating and drying method analyzer that
compares weight before and after heating and drying
while Karl Fischer type analyzer titrates KF reagent that
contains iodine to sample electric-chemically.
2. Karl Fischer method enables a measurement from some
ppm to 100% (water) but operation is complicated and the
unit is expensive. MX/MF is very easy to handle, needs a
shorter time to measure and is reasonably priced.
3. Where required resolution is under 0.01% MX/MF is more
suitable in handling, accuracy and running cost. There is
no difference between data obtained with Karl Fischer
method and heating and drying method.
MX/MF is likely
to have better repeatability than Karl Fischer type.
3. Accuracy
No.
Q
A
1
What does 0.02% of accuracy mean?
It’s the variation and repeatability of moisture content rate
data where same sample is tested with the same conditions
repeatedly. In statistics it is called standard deviation.
4. Samples
No.
Q
A
1
What is the reagent, Sodium Tartrate
Dihydrate like and when is it needed?
It is suitable for testing a moisture analyzer itself since its
moisture content rate is deemed theoretically. Sodium
Tartrate Dihydrate is what Sodium Tartrate is when
chemically bonded to two water molecules or crystal water
and becomes Sodium Tartrate again by releasing the water
molecules when heated. Its moisture content rate is the ratio
of the two water molecules, that is 36.031/230.082=15.66%.
This sample is a standard accessory of MX and optional
accessory of MF (30g x 12pcs).
2
Why isn’t the result of 15.66 obtained?
1. Moisture bonded inside of the material as crystal water
is theoretically 15.66% however ambience has 10%RH
~ 90%RH moisture, which can adhere to the sample in a
mechanical fashion. Also, moisture and/or impurities
left on a pan, and/or measurement accidental errors can
be the reason and the result may vary between 15.0%
and 16.0% in actual measurement.
2. If the difference between the actual result and 15.66 is
big it is concluded that heating temperature may be too
low.
When Sodium Tartrate Dihydrate is tested, accuracy of
measurement of MX/MF-50 should be set MID, heating
temperature, 160C and after pre-heating for 8 minutes 5g of
the sample should be placed on the pan evenly distributed.
3
Is Sodium Tartrate Dihydrate safe?
Is there any special process to handle?
1. It is perfectly harmless. Sodium Tartrate Dihydrate is
used as a flavoring to foods and thus, if eaten, unless it
is more than 218g which is a fatal dose, it is a safe
material. However if it gets on mucosa (In eyes and
nose) it should be washed immediately.
2. There should be no special treatment to the material
even when disposed. It can be disposed of as a
burnable waste.
