Skip to product information
1 of 8

PayPal, credit cards. Download editable-PDF and invoice in 1 second!

GB/T 5121.1-2008 English PDF (GBT5121.1-2008)

GB/T 5121.1-2008 English PDF (GBT5121.1-2008)

Regular price $145.00 USD
Regular price Sale price $145.00 USD
Sale Sold out
Shipping calculated at checkout.
Quotation: In 1-minute, 24-hr self-service. Click here GB/T 5121.1-2008 to get it for Purchase Approval, Bank TT...

GB/T 5121.1-2008: Methods for chemical analysis of copper and copper alloys -- Part 1: Determination of copper content

This Method specifies the determination method of copper content in copper and copper alloys. This Method is applicable to the determination of copper content in copper and copper alloys. The determination range: 50.00%~99.0%.
GB/T 5121.1-2008
GB
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
ICS 77.120.30
H 13
Replacing GB/T 5121.1-1996
Methods for chemical analysis of copper and copper
alloys - Part 1: Determination of copper content
(ISO 1554:1976, ISO 1553:1976, Wrought and cast copper alloys and
unalloyed copper containing not less than 99.90% of copper ?€? Determination of copper content - Electrolytic method, MOD)
ISSUED ON: JUNE 17, 2008
IMPLEMENTED ON: DECEMBER 01, 2008
Issued by: General Administration of Quality Supervision, Inspection and Quarantine;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3
1 Method One - Direct electrolysis-atomic absorption spectrometry ... 6 2 Method Two - Potassium permanganate oxidation of tellurium-electrolysis- atomic absorption spectrometry ... 11
3 Method Three - Electrolysis-spectrophotometry ... 16
Annex A (informative) Control table on clause numbers between Method One of this Part and ISO 1554:1976 ... 22
Annex B (informative) Technical differences between Method One of this Part and ISO 1554:1976 and reasons ... 23
Annex C (informative) Control table on clause numbers between Method Three of this Part and ISO 1553:1976 ... 24
Annex D (informative) Technical differences between Method Three of this Part and ISO 1553:1976 and reasons ... 25
Table D.1 -- Technical differences between Method Three of this Part and ISO 1553:1976 and reason ... 25
Methods for chemical analysis of copper and copper
alloys - Part 1: Determination of copper content
1 Method One -- Direct electrolysis-atomic absorption
spectrometry
1.1 Scope
This Method specifies the determination method of copper content in copper and copper alloys.
This Method is applicable to the determination of copper content in copper and copper alloys. The determination range: 50.00%~99.0%.
1.2 Method principle
After the test material is dissolved by nitric acid and hydrofluoric acid, use hydrogen peroxide to reduce nitrogen oxides. Add lead to reduce the loss of platinum on the anode. Electrolysis causes copper to precipitate on the platinum cathode. Weigh after drying the cathode. The amount of copper
remaining in the electrolyte is determined by flame atomic absorption
spectrometry.
1.3 Reagents
Unless otherwise specified, only reagents and distilled water or deionized water or equivalently pure water that are confirmed as analytically pure are used in the analysis.
1.3.1 Absolute ethanol.
1.3.2 Hydrofluoric acid (??1.13g/mL).
1.3.3 Nitric acid (1+1).
1.3.4 Hydrogen peroxide (1+9).
1.3.5 Ammonium chloride solution (0.02g/L).
1.3.6 Lead nitrate solution (10g/L).
1.3.7 Copper standard stock solution: Weigh 1.0000g of pure copper (the mass 1.6 Analysis steps
1.6.1 Test material
Weigh 2.000g of sample (1.5), to the nearest of 0.0001g.
1.6.2 Determination times
Perform the secondary determination independently. Take the average value. 1.6.3 Blank experiment
Do a blank test with the sample (electrolysis is not necessary).
1.6.4 Determination
1.6.4.1 Place the test material (1.6.1) in a 250mL Teflon beaker. Add 2mL of hydrofluoric acid (1.3.2), 30mL of nitric acid (1.3.3). Cover the watch glass. When the reaction is close to the end, heat at no higher than 80??C until the test material is completely dissolved.
1.6.4.2 Add 25mL of hydrogen peroxide (1.3.4), 3mL of lead nitrate solution (1.3.6). Use ammonium chloride solution (1.3.5) to wash the watch glass and beaker wall and dilute to a volume of about 150mL.
1.6.4.3 Mount the platinum anode and the precisely weighed platinum cathode on the electrolyzer. Soak the net in the solution. Cover the beaker with a split Teflon dish or polypropylene dish.
1.6.4.4 Electrolyze under stirring (current density 1.0A/dm2) until the color of copper fades. Use water to wash the watch glass, beaker wall and electrode rod. Continue electrolysis for 30min. If there is no copper precipitation in the newly submerged electrode part, it means that the electrolysis is complete. 1.6.4.5 Without cutting off the power, slowly raise the electrode or lower the beaker. Immediately use two glasses of water to rinse the electrodes in sequence. Remove the platinum cathode quickly. Dip into two beakers of
absolute ethanol (1.3.1) in turn. Immediately put it into a constant temperature drying oven at 105??C to dry for 3min~5min. Take it out and put it in a desiccator. Cool to room temperature and weigh.
1.6.4.6 Transfer the solution (1.6.4.5) after electrolysis of copper and the first beaker of water (1.6.4.5) that washed the electrode into two 300mL beakers respectively. Cover the watch glass. Evaporate at low temperature to a volume of about 80mL. Cool. Combine the solutions and transfer to a 200mL volumetric flask. Use water to dilute to the scale. Mix well. If the amount of residual copper is greater than 0.0005g, pipette 25.0ml of solution (1.6.4.6) and place in a 100ml volumetric flask. Use water to dilute to the scale. Mix well.
The test material is dissolved in nitric acid. Add lead to reduce the loss of platinum on the anode. Use potassium permanganate to oxidize all tellurium to hexavalent to prevent tellurium precipitation at the cathode. Electrolyze at 2.0A/dm2. Precipitate copper on the platinum cathode. Weigh after drying the cathode. The mass of residual copper in the electrolyte is determined by flame atomic absorption spectrometry.
2.3 Reagents
Unless otherwise specified, only reagents and distilled water or deionized water or equivalently pure water that are confirmed as analytically pure are used in the analysis.
2.3.1 Absolute ethanol.
2.3.2 Nitric acid (1+1).
2.3.3 Potassium permanganate solution (20g/L).
2.3.4 Manganese nitrate solution (20g/L).
2.3.5 Lead nitrate solution (10g/L).
2.3.6 Ammonium chloride solution (0.02g/L).
2.3.7 Copper standard stock solution: Weigh 1.0000g of pure copper (the mass fraction of copper is ???99.95%) and place it in a 250mL beaker. Add 40mL of nitric acid (2.3.2). Cover the watch glass. Heat till it is completely dissolved. Boil to remove nitrogen oxides. Use water to wash the watch glass and beaker wall. Cool. Move into a 1000mL volumetric flask. Use water to dilute to the scale. Mix well. 1mL of this solution contains 1mg of copper.
2.3.8 Copper standard solution: Pipette 10.00mL of copper standard stock solution (2.3.7) and place it in a 500mL volumetric flask. Use water to dilute to the scale. Mix well. 1mL of this solution contains 20??g of copper.
2.4 Instruments
2.4.1 Electrolyzer equipped with automatic stirring device, precision branch ammeter and voltmeter.
2.4.2 Electric heating constant temperature drying oven.
2.4.3 Platinum cathode: A platinum wire with a diameter of about 0.2mm is woven into a mesh of about 36??g per square centimeter. Make it into a net of cylindrical shape (see Figure 1).
2.4.4 Platinum anode: Spiral (see Figure 2).
oxides. Take it down and cool for a while. Use a small amount of water to wash the beaker wall and watch glass. Add 3mL of lead nitrate (2.3.5). Dilute the solution volume with ammonium chloride solution (2.3.6) to about 150mL. 2.6.4.3 Put the magnetic stirring rod into the beaker (2.6.4.2). Place on the electrolysis instrument tray. Start the mixing device. Stir the solution uniformly and add 3mL of potassium permanganate solution (2.3.3) and 5mL of
manganese nitrate solution (2.3.4) dropwise under stirring.
2.6.4.4 Mount the platinum anode and platinum cathode on the electrolyzer. Soak the net in the solution. Cover the tall beaker with two half-piece watch dishes.
2.6.4.5 Stir and electrolyze the solution at a current density of about 2.0A/dm2 on the surface of the cathode until the solution is colorless. Use water to wash the watch glass, beaker wall and electrolysis rod. Reduce the current density to 1.0A/dm2 and continue electrolysis. If there is no copper precipitation in the newly immersed electrode part, it means that the electrolysis is complete (about 1h).
2.6.4.6 Without cutting off the power, slowly raise the electrode or lower the beaker. Immediately use two glasses of water to rinse the electrode. Remove the platinum cathode quickly. And immerse them in two beakers of absolute ethanol (2.3.1). Immediately put it into a constant temperature drying oven at 105??C to dry for 3min~5min. Take it out and place in a desiccator to cool to room temperature.
2.6.4.7 Weigh the electrolytically deposited platinum cathode with the original balance (2.6.4.6).
2.6.4.8 Evaporate the copper solution (2.6.4.5) and the first beaker of electrode washing water (2.6.4.6) to a volume of about 80mL at low temperature. Cool. Combine the solutions and transfer to a 200mL volumetric flask. Use water to dilute to the scale. Mix well. If the residual copper is greater than 0.0005g, pipette 25.0mL of the solution (2.6.4.8). Put it in a 100mL volumetric flask. Use water to dilute to the scale. Mix well.
2.6.4.9 Use air-acetylene flame, in atomic absorption spectrometer, at a wavelength of 324.7nm, with standard solution series at the same time, use water to zero and adjust the absorbance of the test solution. The measured absorbance is subtracted from the absorbance of the blank solution with the test material, and the corresponding copper mass concentration is found from the working curve.
2.6.5 Drawing of working curve
2.6.5.1 Pipette 0ml, 2.50mL, 5.00mL, 7.50mL, 10.00mL, 12.50mL of copper Unless otherwise specified, only reagents and distilled water or deionized water or equivalently pure water that are confirmed as analytically pure are used in the analysis.
3.3.1 Absolute ethanol.
3.3.2 Nitric acid (1+1).
3.3.3 Ammonia (1+1).
3.3.4 Mixed acid: 7 unit-volume of nitric acid (??1.42g/mL), 10 unit-volume of sulfuric acid (??1.84g/mL) and 25 unit-volume of water are mixed well. Cool. 3.3.5 Mixed acid: Take 42mL of mixed acid (3.3.4) in a 500mL volumetric flask. Use water to dilute to the scale. Mix well.
3.3.6 Ammonium citrate solution (500g/L).
3.3.7 Bis (cyclohexanone) oxaldihydrazone (BCO) (1g/L): Weigh 0.5g of BCO in a 300ml beaker. Add 50mL of absolute ethanol (3.3.1), 200mL of warm water to dissolve. Move into 500mL volumetric flask. Use water to dilute to the scale. Mix well.
3.3.8 Neutral red ethanol solution (1g/L).
3.3.9 Copper standard storage solution: Weigh 0.1000g of pure copper (the mass fraction of copper ???99.95%) and place it in a 150mL beaker. Add 10mL of nitric acid (3.3.2). Heat at low temperature to dissolve completely. Boil to remove nitrogen oxides. Use water to wash the watch glass and beaker wall. Cool. Move into a 1000mL volumetric flask. Use water to dilute to the scale. Mix well. 1mL of this solution contains 100??g of copper.
3.3.10 Copper standard solution: Pipette 10.00mL of copper standard stock solution (3.3.9) into a 100mL volumetric flask. Use water to dilute to the scale. Mix well. 1mL of this solution contains 10??g of copper.
3.4 Instruments
3.4.1 Electrolyzer equipped with automatic stirring device, precision branch ammeter and voltmeter.
3.4.2 Electric heating constant temperature drying oven.
3.4.3 Platinum cathode: A platinum wire with a diameter of about 0.2mm is woven into a mesh of about 36??g per square centimeter. Make it into a net of cylindrical shape (see Figure 1).
3.4.4 Platinum anode: Spiral (see Figure 2).
electrode rod newly submerged in water no longer deposits copper.
3.6.3.5 Without cutting off the power supply, quickly remove the tall beaker and replace it with a tall beaker containing about 180mL of water. Continue electrolysis for 15min.
3.6.3.6 Immediately extract the platinum cathode and immerse it in another 250mL beaker filled with water. Move up and down 3 times. Turn off the power and remove the electrodes. Put it in a beaker that is filled with absolute ethanol. After taking it out, put it in a 105??C electric heating constant temperature drying oven to dry for 3min~5min. Take out and place in a desiccator to cool to room temperature.
3.6.3.7 Weigh the platinum cathode after electrolytic deposition with the original balance (3.6.3.6).
3.6.3.8 Determine the amount of residual copper in the solution after
electrolysis as follows.
3.6.3.8.1 Blank test
Pipette the same mixed acid (3.3.4) as the test material solution into a 50mL volumetric flask. Conduct the blank test with test material.
3.6.3.8.2 Combine the electrolyzed electrolyte with a glass of water that has been electrolyzed for 15min. Place in a 500mL volumetric flask. Use water to dilute to the scale. Mix well.
3.6.3.8.3 Pipette 10.00mL~20.00mL into a 50mL volumetric flask. Add 2mL of ammonium citrate solution (3.3.6). Use water to dilute to 25mL. Add 2~3 drops of neutral red ethanol solution (3.3.8). Neutralize with ammonia solution (3.3.3) until the red solution fades and there is an excess of 1.0mL. Add 8.0mL of Bis (cyclohexanone) oxaldihydrazone solution (3.3.7). Use water to dilute to the scale. Mix well. Place still 20min.
3.6.3.8.4 Transfer part of the solution into a 2cm absorption dish. Take the blank solution accompanying the test material as a reference. Measure absorbance at 600nm wavelength of spectrophotometer. Find the mass of the
corresponding copper from the working curve.
3.6.3.9 Drawing of working curve
3.6.3.9.1 Pipet 6 portions of 20.0mL of mixed acid (3.3.5) in a set of 50ml volumetric flasks. Add 0mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, 5.00mL of
copper standard solution (3.3.10) respectively. The following shall proceed according to "add 2mL of ammonium citrate solution" in 3.6.3.3.
3.6.3.9.2 Transfer part of the solution into a 2cm absorption dish. Take reagent

View full details