Applications

1. Method Overview

When iron ions in the sample are atomized, they absorb the resonance line (302.1nm) emitted by the iron hollow cathode lamp, and the absorption intensity is proportional to the iron content in the sample.

2. Scope of Application

Applicable to the determination of iron in graphene leachate.

3.1 Instruments and Equipment

3.1.1 Detection Instruments

Graphite Furnace Atomic Absorption Spectrometer(Iron Hollow Cathode Lamp)

Cooling Circulating Water Device(Pump rated flow: 3.5L/min )

Argon Gas(1 bottle Purity ≥99.99% )

Balance

3.1.2 Pretreatment Equipment

Volumetric Flask, Micropipette

3.2 Reagents

3.2.1 Reagents

Nitric Acid(Ultra-pure Grade)

Hydrochloric Acid(Ultra-pure Grade)

4. 4. Operation Procedure

4.1 Preparation of Test Solution

Weigh 1g of graphene slurry into a beaker, add 20mL of aqua regia, digest on an electric hot plate at 200°C for 30 minutes, remove acid for 5 minutes, cool to room temperature, transfer to a 100mL volumetric flask, dilute to the mark with deionized water, mix well, and wait for testing.

4.2 Preparation of Standard Solution

Preparation of Iron Standard Working Solution (10μg/mL): Accurately pipette 1.00mL of iron standard stock solution (1000μg/mL) into a 100mL volumetric flask, dilute to the mark with (1+99) nitric acid solution, and shake well.

Preparation of Iron Standard Series: Pipette 0.00mL, 0.25mL, 0.50mL, 1.00mL, and 1.50mL of iron standard working solution (10μg/mL) into 100mL volumetric flasks, dilute to the mark with deionized water, and shake well. Prepare standard series containing 0.00ng/mL, 25.00ng/mL, 50.00ng/mL, 100.00ng/mL, and 150.00ng/mL of iron respectively.

4.3 Sample Testing

When testing the iron content in the sample, the graphite tube needs to be coated. Pipette 50μL of 10% zirconium solution into the graphite tube, heat according to the above heating program, and complete 3-5 coatings. Adjust the instrument, set the instrument parameters, and then pipette 10μL of the standard series solution and sample solution into the graphite tube in sequence to complete the sample testing.

4.4 Result Calculation

The iron concentration in the sample is calculated by the following formula:

Where:

ρ(Fe): Mass concentration of iron in the sample, in milligrams per kilogram (mg/kg);

Ρ1: Concentration of iron in the test sample obtained from the calibration curve, in nanograms per milliliter (ng/mL);

V1: Volume of the test sample, in milliliters (mL);

m: Sample weight, in grams (g);

1000: Conversion coefficient.