GMAP Quiz

Which is NOT the measurement parameter to be considered for moisture analysis method development？

• Sample weight (g)

• Drying temperature (degree C)

• Drying time (min)

• Drying program (standard/rapid/gentle)

Answer explanation

Drying time (min) is depend on the Switch-off criterion (SOC). It is not commonly a parameter to be determined during method development.

Which sample start weight is recommended for general samples on a moisture analyzer?

• Below 3g

• 3-5g

• 10g

• Same as drying oven method.

Answer explanation

Too little sample may lead to a greater possible error in result.

3-5g is recommended for samples to cover the pan with thin layer.

Which method setting modification in the moisture analyzer that able to get faster results?

• Increase drying temperature

• Select standard drying program

• Increase sample weight

Answer explanation

Modification to be done to get faster results: Increase drying temperature, reduce sample size, select rapid drying.

Modifications should be validated to ensure consistent results.

What is the main technique used in the moisture analyzer?

• Gravimetric method

• Karl-Fischer titration

• Thermogravimetric method

• Heating

Answer explanation

A moisture analyzer uses thermogravimetric method to identify loss of drying, which is the same technique as the drying oven.

What type of sample preparation is recommended before moisture analysis?

• Dissolve sample in water

• Homogenize the sample

• Freezing the sample

• Filtering the sample

Answer explanation

A sample should be at homogeneous and even granulation state for even heating.

Syarifah wants to measure moisture content of orange juice. Can she use a moisture analyzer to perform the analysis?

• Yes, with glass fiber filter.

• Yes, with no additional accessories needed.

• No, she can only use Karl-Fischer for liquid samples.

Answer explanation

Glass Fiber Filter increases sample surface and improves evaporation.

Stephanie wants to measure moisture content of paint. Which drying program she should use?

• Rapid drying, because paint is a fluid sample.

• Gentle drying, to avoid forming of skin on the surface of the paint.

• Standard drying with higher temperature.

How long does it take to run a moisture verification test using SmartCal?

• 5 minutes

• 10 minutes

• 15 minutes

• Until all moisture of SmartCal has been removed

Answer explanation

SmartCal is used to verify performance of a moisture analyzer by operating at a fixed 10 minutes under preset temperature. The verification is passed when the result lies within the SmartCal control limits.

When does the moisture analyzer end the measurement?

• When the switch-off criterion (SOC) is reached

• When all water is evaporated.

• Before the sample starts to decompose

Answer explanation

SOC defines the criterion when does the instrument should end the drying process. Typically SOC3 (1mg/50s) is selected for general samples.

 What is the heating principle of the moisture analyzer?

• Infrared and conduction

• Conduction and convection

• Infrared and convection

• Infrared only

Answer explanation

Moisture analyzer uses Infrared and conduction, whereby drying oven uses convection and conduction to perform moisture analysis.