Post on 31-Jul-2015
Features of KERN MLB
• Controlled drying process with 1 halogen quartz heaters
• Heating from 50-160°C in steps up to 1°C• Terminates drying when weight is constant
or after fixed time period• Displays last measured value till replaced
by new measurement• Data can be printed or saved to PC via
RS-232 interface
Features of KERN MLB
• Quick calibration with external weights• Optional temperature calibration set: sensor and
display device• 3 LED displays: temperature, drying status, drying
time• Ambient conditions: 15°C - 35°C, max. 80% air
humidity; not condensing• Balance contains memory for automatic sequence of
20 complete drying processes• 4 programmable heating profiles: standard, fast,
staged (freely selectable time / temperature stages), and soft
Technical Specifications of KERN MLBRead Out -0.001g or 0.01%Max Sample Weight -50 gReproducibility with 2g sample
-0.5%Reproducibility with 10g sample
-0.02%Heater Type halogen Heaters -1 x 400WTemp. Range ºC -50C-160C
Uses of the Moisture analyzer
• Plastic moisture analyzer
• Trace moisture analyzer
• Food moisture analyzer
• Wood moisture analyze
Answers to Questions
1. Discuss Moisture content determination.
The moisture contained in a material comprises ALL the substances which vaporizes on heating leads to weight loss of the sample.
Other substances
• Organic solvents
• Alcohol
• Greases
• Oils
• Aromatic components (decomposition and combustion products)
Answers to Questions
2. Advantages of this method compared with other.
Much faster reading and determination of the moisture content.
Accuracy of the Percent moisture data gathered.
Easy and hassle free to operate.
Analyzes broad variety of materials
Answers to Questions
3. Importance to know moisture content of acacia and starch in tablet production:
Standard Properties of Acacia/ starch:
3a. Stability and agglomeration in powders
3b. Microbiological stability
3c. Flow properties
Answers to Questions
• To cont.
3d. Dry substance content and conc/ purity
3e. Commercial grade
3f. Nutritional value of the product
3g. Legal conformity
Answers to Questions
• Calculations
Formula to determine percent moisture:
% moisture = weight loss X 100
Start up weight
What if: Initial weight- 10 grams
After heating- 8.9625 grams
Answers to Questions
5. Principle involved to determine moisture content using moisture analyzer
Moisture content data is provided as a percentage of initial mass of the residual dry mass.
Principle in Moisture analyzer
QUARTZ GLASS HEATER
SAMPLE
Constant even drying on the sample at selected temperature
The analysis automatically terminates when drying is complete, dry weight is stable at a fixed time
Other METHODS of Moisture content determination
1. Thermo-gravimetric method
-Are weighing- drying method in which samples are dried until their mass is constant.
-These are suitable for all thermally stable substances with a moisture content of >0.1%
Other METHODS of Moisture content determination
• Examples of Thermogravimetic methods
1. Infrared drying
2. Halogen drying
3. Drying oven with balance
4. Microwave drying
Other METHODS of Moisture content determination
2. Chemical analysis ex. KARL FISCHER method
-Used for many substances as reference method.
-A chemical analysis procedure which is based on oxidation of sulfate by iodine in a methanolic hydroxide soln.
Other METHODS of Moisture content determination
• KARL FISCHER METHOD
- Drugs that contain no constituents volatile at 105C
- Samples with high moisture content
- Water contents in PPM
• CALCIUM CARBIDE
Other METHODS of Moisture content determination
3. Spectroscopic method
-Indirect measurement method that requires calibration to determine the relation between the display of spectrometer and the value determined by a reference method.
Other METHODS of Moisture content determination
• Examples of Spectroscopy methods
1. Infrared spectroscopy
2. Microwave spectroscopy
3. NMR
Other METHODS of Moisture content determination
4. OTHERS
Density determination
Refractometry
Conductivity
Gas Chromatography
Azeotropic (Toluene Distillation)
Deo point and electrolyte hygrometer
DATA RESULT and sample calculation
ACACIA STARCH
Weight of the sample before
14. 987 grams 15.366 grams
Weigh of the sample after
14.958 grams 15. 297 grams
Percent moisture CALC
? ?
Percent moisture MA
0.1935% 0.4490