For a solid sample, which sampling techniques can be used to obtain a representative sample?

• grab sampling

• continuous sampling

• both

Solid sample need to be treated before a representative sample can be obtained. Select the treatment procedure that can be done.

• grind the sample into smaller particle size

• heating the sample

• both

Storing sample in a suitable container is important, EXCEPT

• to avoid contamination

• to prevent decomposition

• to prevent heat loss

• to prevent lost of analyte

Sample contains metal should be stored in

• plastic container

• glass container

• both

The following problems can occur during storage of sample, EXCEPT

• loss of analyte due to vaporization

• side reaction

• decomposition by bacteria

• spillage

Sample contains organic substance can be eliminated by performing

• total dissolution

• wet digestion

• drying

When preparing a representative sample, we should avoid the following, EXCEPT

• losing any analyte

• adding new interference

• preparing sample in its best size and form

Which of the following is NOT a technique used to eliminate interferences?

• distillation

• precipitation

• solid-liquid extraction

• filtration

Dry ashing is a process to eliminate

• inorganic substance by heating in a furnace

• organic substance by heating in a furnace

• organic substance by dissolving in oxidizing acid

analytes are

• samples to be analyzed

• components of sample to be analyzed

• representative samples