1-determination of ferrous [Fe+2] ion in a sample solution in(g\L).2-determination of (ferrous and ferric )in a mixture. 3-determination of purity of KClO3 sample. 4-determination of [fe+2] in unknown sample. 5-determination of total iron [Fe] in an iron ore. 6-determination of [Fe+3] in a sample. 7-determination of available chlorine in bleaching powder.
It is to prevent contamination since moisture from air could be absorbed by the sample.
Margin of error, level of significance and level of power are all elements that will affect the determination of sample size.
The FOUR steps to follow in order to design a good sample are: I. Determination of the data to be collected or described II. Determination of the population to be sampled III. Choosing the type of sample IV. Deciding on the sample size
to remove the moisture in the sample. if you want to get a mass of the sample in the laboratory .
The moisture decreases.
to avoid the light go through in the sample and keep the sample cool also.
Most of the vitamin tests are conducted by acquiring a sample of blood, and then preparing plasma or serum from the blood sample.
Moisture in grain and grain foods is measured by weight, or by weighing before and after it is dried. Two grams of the grain sample is accurately weighed into a dry dish with a cover. The sample is dried in a forced draft oven or a vacuum oven. The sample is weighted again, and the change in weights represents the amount of moisture that was lost. Moisture can also be measured by using an NIR instrument, which is much quicker, but not as dependable.