Applications

Determination of Nickel in Reflective Coating of Mirrors (Flame Atomic Absorption Spectrometry)

September 9, 2025

1. Method Overview

After the sample is pretreated, it is introduced into an atomic absorption spectrometer and atomized by flame to determine the absorbance. Within a certain concentration range, the absorbance value is proportional to the content, and quantification is performed by comparison with the standard series.

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	Polytetrafluoroethylene (PTFE) Beakers	Several	Volume: 100 mL	Including PTFE beaker lids
3	Adjustable Hot Plate	1 set	Temperature range: Room temperature ~ 300 ℃	–
4	Micropipettes	1 each	Volume ranges: 20 μL ~ 200 μL; 1000 μL ~ 5000 μL	–
5	Volumetric Flasks	Several	Volumes: 100 mL, 1000 mL	–
6	Colorimetric Tubes	Several	Volume: 25 mL	–

2.2 Reagents

2.2.1 Raw Reagents

Serial No.	Name	Technical Requirements	Remarks
1	Nitric Acid	MOS Grade	–

2.2.2 Prepared Reagents

Serial No.	Name	Preparation Method	Remarks
1	Nitric Acid Solution (1+99)	Measure 10 mL of nitric acid, add it to 990 mL of water, and mix well.	–

2.3 Reference Standards

2.3.1 Stock Solution

Serial No.	No.	Name	Technical Requirements	Remarks
1	GBW08618	Nickel Single-Element Standard Solution	Concentration: 1000 μg/mL	National Institute of Metrology, China

3. Operation Procedure

3.1 Sample Preparation

3.1.1 Preparation of Test Solution

Sample Pretreatment:
Place the entire mirror in a PTFE beaker with the reflective side facing up. Add 1 mL of water and 5 mL of nitric acid (the liquid level must completely cover the reflective surface of the mirror). Cover the beaker, heat for digestion for 1 hour until the reflective coating of the mirror disappears completely. Remove the beaker, cool it down, dilute the solution to the marked volume in a 25 mL colorimetric tube, shake well, and transfer it to a plastic bottle for storage. Prepare a sample blank simultaneously.

3.1.2 Preparation of Standard Solutions

Preparation of Nickel Standard Series:
Pipette 0 mL, 25 μL, 50 μL, 100 μL, and 150 μL of nickel standard solution (1000 μg/mL) respectively into 100 mL volumetric flasks. Dilute to the marked volume with nitric acid solution (1+99) 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, and 1.50 μg/mL.

3.2 Sample Testing

Testing Conditions
Reference Conditions for Flame Atomic Absorption Spectrophotometer Detection

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

Sample Testing
Adjust the instrument to the optimal working state and zero it with water. Determine the absorbance of the standard solutions, blank test solution, and test solution in sequence.

Subtract the absorbance of the zero-standard solution from the absorbance of each standard solution. Plot a working curve with mass concentration (μg/mL) as the abscissa and the corresponding absorbance as the ordinate. Based on the measured absorbance of the test solution, find the mass concentration of nickel from the working curve.