Determination of cobalt (Co2+) content and manganese (Mn2+) content by atomic absorption method

A.

After the sample is diluted, it is measured by flame atomic absorption method, and the concentration of the element to be measured is calculated by the absorption law

A.

A.

A.

A.

A.

A.

A.

A.

A.

A.

Adjust the instrument according to the instrument instruction, and heat the hollow cathode lamp of cobalt and manganese for 15 minutes

Table A.

A.

Using the prepared atomic absorption spectrophotometer, sample the absorbance value A _{0 of the} mixed standard solution of cobalt (Co ²⁺ ) and manganese (Mn ²⁺ ) .

A.
4.
3 Sample analysis

Weigh 1.
0g sample, accurate to 0.
1mg, place it in a 100mL volumetric flask, dilute to the mark, and mix
.
Take 10mL of this solution in another 100mL volumetric flask, dilute to the mark, mix well, and measure the absorbance values ​​A of cobalt and manganese in this sample solution respectively
.

A.
5 Result calculation

The mass fraction w of cobalt (Co ²⁺ ) or manganese (Mn ²⁺ ) content, expressed in %, calculated according to formula (A, 1):

Where:

A ₁ —The absorbance value of cobalt or manganese in the sample solution;

C- cobalt (of Co ²⁺ ), manganese (Mn ²⁺ ) Cobalt mixed standard solution (of Co ²⁺ ) or manganese (Mn ²⁺ values) concentration, in micrograms milliliter (ug / mL):

Ao— The absorbance value of cobalt or manganese in the mixed standard solution of cobalt (Co ²⁺ ) and manganese (Mn ²⁺ );

m—the value of the mass of the sample, in grams (g);

100—The value of the sample solution volume, in milliliters (mL);

10—The dilution factor of the sample
.

The calculation result is expressed to one decimal place
.

Take the arithmetic mean of the two parallel determination results as the determination result
.
The absolute difference between the two parallel determination results is not more than 0.
5%
.

Related links: Test method for mixed catalyst solution of cobalt acetate, manganese acetate and hydrobromic acid (8)