AAS

Question 1

Food can be declared adulterated if:

Answer 1

a) a substance is added, which is injurious to health
b) cheaper or inferior quality item added to food
c) any valuable constituent is extracted from main food
d) The quality of food is below the standards
e) any substance has been added to increase bulk or weight
f) to make it appear more valuable.

Question 2

Adulterated food is dangerous as:

Answer 2

a) it may be toxic and effect health;
b) it could deprive nutrients required to maintain proper health,
c) it may cause intoxication or problems such as allergy in sensitized individuals.

Question 3

Adulterated food is dangerous as:

Answer 3

a) it may be toxic and effect health;
b) it could deprive nutrients required to maintain proper health,
c) it may cause intoxication or problems such as allergy in sensitized individuals.

Question 4

Adulterants in food can be categorized into following categories:

Answer 4

 Intentional adulteration
 Unintentional adulteration

Question 5

HEAVY METALS

Answer 5

• Many studies have shown that heavy metals have toxic effects even at very low concentrations.

• Heavy metals are natural components of the Earth’s crust and cannot be degraded nor destroyed.

• Besides the various minerals found in our daily diet, toxic heavy metals such as Cd, Pb, Hg, and Ni can be found in food products.

• These elements can be toxic, even at relatively low concentrations

• High metals’ concentration like lead (Pb), cadmium (Cd), copper (Cu) and nickel (Ni) in food have been correlated with the metal pollution in soil, air and water.

• Heavy metals are dangerous in their form of captions and highly toxic when bonded to their short chains of carbon atoms.

• Therefore, controlling the heavy metal concentration in food like cereals, fish, and vegetables should be made to ensure their safety.

Question 6

The instrumental analytical methods may be employed to measure the concentration level of heavy metals in various samples.

Answer 6

1) Atomic absorption spectrometry (AAS),

2) Atomic emission/fluorescence spectrometry (AES/AFS)

3) Inductively coupled plasma mass spectrometry (ICP-MS)

4) Inductively coupled plasma optical emission spectrometry (ICP-OES)

5) X-ray fluorescence (XRF)

6) Anodic striping voltammetry (AVS).

Question 7

Digestion (Heavy Metal)

Answer 7

• Different digestion methods of food samples were investigated before to determine the best method for the recovery of the heavy metals

Question 8

Procedure of Digestion (Heavy Metal)

Answer 8

• Digestion is performed with the aim of separating analyte from the matrix and to avoid interaction of organic substance with metal ions or chemical reagents.

• The choice of digestion procedure depends on the nature of organic substance and the content of inorganic components, as well as the choice of heavy metal, which is selected for the analysis.

• The most commonly used methods for the sample digestion are: dry ashing, wet digestion, and microwave digestion.

Question 9

Data Calculation of Heavy Metals

Answer 9

• To analyse samples by the ICP-AES and the AAS techniques, the calibration curve of each element must be determined first with good linear regression.

 The coefficient of determination is often written as R2.

Question 10

Principle of AAS

Answer 10

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