Applications

Determination of Nickel in Zinc Alloy (Flame Atomic Absorption Spectrometry)

October 10, 2025

1. Method Overview

The sample is digested with hydrochloric acid, hydrogen peroxide, and nitric acid solutions. In a dilute hydrochloric acid medium, the absorbance of nickel is measured using an air-acetylene flame at a wavelength of 232.0 nm with an atomic absorption spectrometer.

2. Instruments and Reagents

2.1 Instruments and Equipment

2.1.1 Testing Instruments

Serial No.	Name	Quantity	Technical Requirements	Accessories
1	Flame Atomic Absorption Spectrophotometer	1 set	–	Nickel Hollow Cathode Lamp
2	Air Compressor	1 set	Rated discharge pressure: 0.3 MPa	–
3	Acetylene Gas	1 cylinder	Purity ≥ 99.99%	–

2.1.2 Sample Pretreatment Equipment

Serial No.	Name	Quantity	Technical Requirements	Accessories
1	Electronic Balance	1 set	Sensitivity: 0.1 mg	–
2	Beaker	Several	Volume: 100 mL	–
3	Glass Watch Glass	Several	Diameter: 70 mm	–
4	Adjustable Hot Plate	1 set	Rated temperature range: Room temperature ~ 300 ℃	–
5	Micropipette	1 each	Ranges: 20 μL ~ 200 μL, 100 μL ~ 1000 μL, 1000 μL ~ 5000 μL	–
6	Volumetric Flask	Several	Volume: 100 mL	–
7	Colorimetric Tube	Several	Volumes: 25 mL, 50 mL	–

2.2 Reagents

2.2.1 Raw Reagents

Serial No.	Name	Technical Requirements	Remarks
1	Nitric Acid	MOS Grade	–
2	Hydrochloric Acid	Guaranteed Reagent (GR)	–
3	Hydrogen Peroxide	Guaranteed Reagent (GR)	Note: There is a typo “过氧化氧” in the original document; corrected to “Hydrogen Peroxide” according to the context.

2.2.2 Prepared Reagents

Serial No.	Name	Preparation Method	Remarks
1	Hydrochloric Acid Solution (1+5)	Measure 20 mL of nitric acid and mix it uniformly with 100 mL of water.	Note: There may be a typo in the original document (nitric acid mentioned for hydrochloric acid solution preparation); the preparation method follows the original text.
2	Hydrochloric Acid Solution (1+1)	Measure 50 mL of hydrochloric acid and mix it uniformly with 50 mL of water.	–

2.3 Reference Standards

2.3.1 Stock Solution

Serial No.	No.	Name	Technical Requirements	Remarks
1	GBW 08618	Nickel Single-Element Standard Substance Solution	Concentration: 1000 μg/mL	Provided by National Institute of Metrology, China

3. Operational Procedures

3.1 Sample Preparation

3.1.1 Preparation of Test Solution

Sample Pretreatment

Weigh 0.5 g of the sample (accurate to 0.0001 g) and place it in a 100 mL beaker. Add 5 mL of hydrochloric acid solution (1+1), add 1 mL of hydrogen peroxide dropwise, cover with a watch glass, and heat on a hot plate at 150 ℃ until the reaction is complete. Remove and cool, then add 0.5 mL of nitric acid, heat again at 180 ℃ for 30 minutes. Remove and cool, transfer the solution to a 50 mL colorimetric tube with deionized water, dilute to the marked volume with deionized water, and mix well. Perform a blank test following the same procedure as the sample.
Preparation of Sample Test Solution

Accurately pipette 5 mL of the original sample solution into a 25 mL colorimetric tube, add 2.5 mL of hydrochloric acid solution (1+5), dilute to the marked volume with deionized water, and mix well. Prepare a blank test solution simultaneously; except for not adding the sample, the type and amount of reagents added to the blank test solution are the same as those of the test solution.

3.1.2 Preparation of Standard Solutions

Preparation of Nickel Standard Series

Pipette 0 μL, 25 μL, 50 μL, 100 μL, 150 μL, and 200 μL of the nickel standard solution (1000 μg/mL) into separate 100 mL volumetric flasks respectively. Add 10 mL of hydrochloric acid solution (1+5) to each flask, dilute to the marked volume with deionized water, and mix well. The concentrations of this standard series are 0 μg/mL, 0.25 μg/mL, 0.50 μg/mL, 1.00 μg/mL, 1.50 μg/mL, and 2.00 μg/mL.

3.2 Sample Testing

1) Testing Conditions

Reference Conditions for Flame Atomic Absorption Spectrophotometer

Parameter	Specification
Wavelength	232.0 nm
Spectral Bandwidth	0.1 nm
Element Lamp Current	4.0 mA
Burner Height	6 mm
Fuel Flow Rate	1300 mL/min
Air Compressor Pressure	0.22 MPa

2) Sample Testing

Introduce the nickel standard series solutions into the flame atomizer in ascending order of concentration, and measure their absorbance. Plot a standard curve with the mass concentration of nickel in the standard series as the abscissa and the corresponding absorbance as the ordinate.

Under the same experimental conditions as those for determining the standard solutions, introduce the blank solution and the sample test solution into the atomizer respectively, measure their corresponding absorbance, and perform quantitative determination by comparison with the standard series.