Question

Prelab Questions

1. Once digested, what are 2 methods of measuring the content of a metal in solution?

2. In what cases would microwave digestion be unnecessary for a solid sample?

3. Why is microwave digestion inappropriate for organic analytes?

4. If a material sample claims zinc content of 6 mg Zn per 30 g sample, what is the resulting concentration in ppm if 0.825 g are digested and diluted in 100 mL of water?

Answer 1

Prelab Questions-

Answer-1

Once digested, followings are 2 methods of measuring the content of a metal in solution-

• Flame Atomic Absorption spectroscopy(AAS) is one of the tool to measure the concentration of metals in given solution generally expressed in ppm.
• Inductively coupled plasma (ICP)method is another method to measure concentration of metals in given solution .

Answer-2

Microwave digestion be unnecessary for a solid sample in the following cases-

for thermally unstable and air-sensitive materials for examples sulfides and organic frameworks.

Answer-3

Use of different digestion reagents which are which are important eitherfor complete decomposition or the matrix or to stabilize specific elements might limit the use of specific analytical instrumentation methods for Organic analytes.

Answer-4

Sample claims zinc content of 6 mg Zn per 30 g sample

so, 0.825 g of sample contains Zinc=(0.825 x 6)/30

0.825 g of sample contains Zinc =0.165 mg

thus 0.165 mg in 100 ml water

as we know mg/ml is called ppm

so Concentration in ppm=0.165/100

= 0.00165 ppm