Ash Analysis Flashcards
1
Q
Definition of Ash
A
Inorganic residue remaining after either ignition or complete oxidation of organic matter
(Total of all inorganic elements)
2
Q
Combustion is done between what range of temperature
A
500 - 700 degrees C
3
Q
Types of Ashing
A
Dry - % ash determination
Wet - samples with high fat (mineral determination)
Low Temperature/Plasma
- used to prevent loss of trace and volatile minerals
4
Q
Dry Ashing
A
High temp (525C or greater)
Leaves inorganic material to be quantified gravimetrically
5
Q
Calculations of Ash Content
A
%Ash (fwb) = wt. of ash/weight of sample *100
%ash (dwb) = wt. of ash/wt. of dry sample *100
6
Q
Sources of Error (Ashing)
A
- Sample not representative
- Microelement contamination
- Loss of sample in drying before ashing
- Volatilization of elements
- Incomplete combustion
7
Q
Microwave Ashing
A
Wet & Dry Ashing
