Methods for chemical analysis of lithium carbonate,lithium hydroxide monohydrate and lithium chloride—Part 4:Determination of potassium and sodium content—Flame atomic absorption spectrometric method
1 Scope
This part of GB/T 11064 specifies the methods for determining the potassium and sodium content in lithium carbonate, lithium hydroxide monohydrate and lithium chloride.
This part is applicable to the determination of potassium and sodium content in lithium carbonate, lithium hydroxide monohydrate and lithium chloride within the range of 0.0010%～0.40%.
2 Method summary
The test samples of lithium carbonate and lithium hydroxide are decomposed with hydrochloric acid, and test sample of lithium chloride is dissolved with water. In diluted hydrochloric acid medium, determine with air-acetylene flame and standard addition method at the wavelength of 589.0 nm and 766.5 nm of atomic absorption spectrometer.
3 Reagents
Unless otherwise specified, guaranteed reagents and secondary deionized water are used for purpose of this part.
3.1 Hydrochloric acid (1+1).
3.2 Sodium standard storage solution: weigh 2.5420 g sodium chloride (reference reagent), which has been ignited at 500℃ ~ 600℃ for 1.5 h in advance and cooled to room temperature in a dryer, put it in a 250 mL plastic breaker, dissolve it in 100 mL water, add 20 mL hydrochloric acid (3.1), transfer it to a 1 000 mL volumetric flask, dilute to the scale with water, and shake well. Keep them in a plastic bottle. This solution contains 1 mg Na per 1 mL.
3.3 Sodium standard solution: take 0.50.00 ml sodium standard storage solution (3.2), put it in a 500 mL volumetric flask, dilute to the scale with water, mix well, and keep it in plastic bottles. This solution contains 100 μg Na per 1 mL.
3.4 Potassium standard storage solution: weigh 1.907 0 g potassium chloride (reference reagent) which has been ignited at 500℃ ~ 600℃ for 1.5 h in advance and cooled to room temperature in a dryer, put it in a 250 mL plastic cup, dissolve it in 100 mL water, add 20 mL hydrochloric acid (3.1), transfer it to a 1 000 mL volumetric flask, dilute it to the scale with water, and shake well. Store them in a plastic bottle. This solution contains 1 mg Ka per 1 mL.
3.5 Potassium standard solution: take 50.00 mL potassium standard storage solution (3.4), put it in a 500 mL volumetric flask, dilute to the scale with water, mix well, and store it in plastic bottles. This solution contains 100 μg Ka per 1 mL.
3.6 Potassium and sodium standard mixture: take 50.00 mL sodium standard solution (3.3) and 50.00 mL potassium standard solution (3.5), put them in a 500 mL volumetric flask, dilute to the scale with water, shake well and keep them in plastic bottles. This solution contains 10 μg Ka and 10 μg Na per 1 mL.
Foreword i
1 Scope
2 Method summary
3 Reagents
4 Apparatus
5 Test sample
6 Analytical procedures
7 Calculation of analysis result
8 Precision
9 Test report
