1
/
din
12
PayPal, credit cards. Download editable-PDF and invoice in 1 second!
GB 15892-2020 English PDF
GB 15892-2020 English PDF
Preț obișnuit
$245.00 USD
Preț obișnuit
Preț redus
$245.00 USD
Preț unitar
/
pe
Nu am putut încărca disponibilitatea pentru ridicare
Delivery: 2 working-hours manually (Sales@ChineseStandard.net)
Need delivered in 3-second? USA-Site: GB 15892-2020
Get Quotation: Click GB 15892-2020 (Self-service in 1-minute)
Historical versions (Master-website): GB 15892-2020
Preview True-PDF (Reload/Scroll-down if blank)
GB 15892-2020: Polyaluminium chloride for treatment of drinking water
GB 15892-2020
GB
NATIONAL STANDARD OF THE
PEOPLE?€?S REPUBLIC OF CHINA
ICS 71.100.80
G 77
Replacing GB 15892-2009
Polyaluminium chloride for treatment of drinking
water
ISSUED ON: JULY 23, 2020
IMPLEMENTED ON: AUGUST 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the PRC.
Table of Contents
Foreword ... 3??
1 Scope ... 4??
2 Normative references ... 4??
3 Molecular formula ... 5??
4 Product classification ... 5??
5 Requirements ... 5??
5.1 Raw material requirements ... 5??
5.2 Technical requirements ... 5??
6 Test methods ... 6??
6.1 General ... 6??
6.2 Determination of alumina (Al2O3) content ... 6??
6.3 Determination of basicity ... 12??
6.4 Determination of density ... 13??
6.5 Determination of insoluble matter content ... 14??
6.6 Determination of pH value ... 15??
6.7 Determination of iron content ... 15??
6.8 Determination of arsenic content ... 15??
6.9 Determination of lead content ... 20??
6.10 Determination of cadmium content ... 24??
6.11 Determination of mercury content ... 27??
6.12 Determination of chromium content ... 32??
7 Inspection rules ... 33??
8 Marking, packaging, transportation and storage ... 34??
Appendix A (Informative) Determination of coagulation performance ... 36??
Polyaluminium chloride for treatment of drinking
water
Warning - The strong acids and bases used in this Standard are corrosive.
During use, it shall avoid inhalation or contact with the skin. If splashed
on the body, it shall rinse immediately with plenty of water; in severe
cases, it shall seek medical attention immediately.
1 Scope
This Standard specifies the requirements, test methods, inspection rules,
marking, packaging, transportation and storage of polyaluminium chloride for
treatment of drinking water.
This Standard applies to polyaluminium chloride for treatment of drinking water.
The product is mainly used for the purification of drinking water.
2 Normative references
The following documents are indispensable for the application of this document.
For the dated references, only the editions with the dates indicated are
applicable to this document. For the undated references, the latest edition
(including all the amendments) are applicable to this document.
GB/T 191 Packaging - Pictorial marking for handling of goods
GB/T 320 Synthetic hydrochloric acid for industrial use
GB/T 601 Chemical reagent - Preparations of reference titration solutions
GB/T 602 Chemical reagent - Preparations of standard solutions for impurity
GB/T 603 Chemical reagent - Preparations of reagent solutions for use in
test methods
GB/T 610-2008 Chemical reagent - General method for the determination of
arsenic
GB/T 4294 Aluminium hydroxide
GB/T 6678 General principles for sampling chemical products
the excess EDTA solution, to get alumina (Al2O3) content.
6.2.1.2 Reagents and materials
6.2.1.2.1 Carbon dioxide-free water.
6.2.1.2.2 Nitric acid solution: 1+12.
6.2.1.2.3 Aqueous ammonia solution: 1+1.
6.2.1.2.4 Disodium ethylenediaminetetraacetic acid (EDTA) solution: c(EDTA)
is about 0.05 mol/L.
6.2.1.2.5 Acetic acid-sodium acetate buffer solution (pH=5.5): WEIGH 272 g of
sodium acetate (trihydrate) and dissolve it in water; ADD 19 mL of glacial acetic
acid; and dilute to 1000 mL.
6.2.1.2.6 Alumina standard solution: 1 mL contains 0.001 g of Al2O3. WEIGH
0.5293 g of high-purity aluminium (???99.99%), accurate to 0.2 mg. PLACE it in
a 200 mL polyethylene cup; ADD 20 mL of water; ADD about 3 g of sodium
hydroxide, to make it all dissolved and transparent (if necessary, heat on a
water bath). USE hydrochloric acid solution (1+1) to adjust to acidic and then
add 10 mL, to make it transparent, cool; TRANSFER to a 1000 mL volumetric
flask; DILUTE to the mark and shake well.
6.2.1.2.7 Zinc chloride reference titration solution: c(ZnCl2) is about 0.025 mol/L;
prepare as follows:
a) Preparation: WEIGH 3.5 g of zinc chloride (ZnCl2); DISSOLVE it in
hydrochloric acid solution [0.05% (volume fraction)]; DILUTE to 1 L and
shake well.
b) Calibration: PIPETTE 20 mL of EDTA solution and 40 mL of alumina
standard solution; PUT them in a 250 mL conical flask; follow the steps in
6.2.1.3 "ADD 10 mL of nitric acid solution..." to start the operation. READ
the consumption V (mL) of the zinc chloride reference titration solution. In
addition, pipette 20 mL of EDTA solution and place it in a 250 mL conical
flask. Follow the steps in 6.2.1.3 "ADD 10 mL of nitric acid solution..." to
start the operation. READ the consumption V0 (mL) of the zinc chloride
reference titration solution.
c) Result calculation: The concentration of zinc chloride reference titration
solution, c(ZnCl2), value expressed in moles per liter (mol/L), is calculated
according to formula (1):
Where:
V0 - The value of the volume of sodium hydroxide reference titration solution
consumed in the blank test, in milliliters (mL);
V - The value of the volume of sodium hydroxide reference titration solution
consumed for determination of the sample, in milliliters (mL);
c - The exact value of the actual concentration of sodium hydroxide reference
titration solution, in moles per liter (mol/L);
M - The value of the molar mass of hydroxide (OH-), in grams per mole (g/mol)
(M=16.99);
m - The value of the mass of the test portion, in grams (g);
w1 - The mass fraction of alumina measured in 6.2;
V1 - The value of the volume of test solution A pipetted, in milliliters (mL) (V1=25);
VA - The value of the total volume of test solution A, in milliliters (mL) (VA=250);
M1 - The value of the molar mass of aluminium, in grams per mole (g/mol)
(M1=26.98);
M2 - The value of the molar mass of alumina, in grams per mole (g/mol)
(M2=101.96).
6.3.5 Allowable difference
USE the arithmetic mean of the parallel determination results as the
determination result. The absolute difference of the parallel determination
results is not more than 2.0%.
6.4 Determination of density
6.4.1 Method summary
From the depth of immersion when the densitometer reaches the equilibrium
state in the measured liquid, read the density value.
6.4.2 Apparatus
6.4.2.1 Densitometer: The division value is 0.001 g/cm3.
6.4.2.2 Constant-temperature water bath: Controllable temperature (20??0.1)??C.
6.4.2.3 Thermometer: The division value is 0.1 ??C.
standard solution respectively in five 100 mL volumetric flasks. Respectively
add 5.0 mL of hydrochloric acid and 20 mL of thiourea solution; USE water to
dilute to the mark and shake well; PLACE for more than 30 min. The mass
concentrations of arsenic in this series of solutions are 0 ??g/L, 4 ??g/L, 8 ??g/L,
12 ??g/L, 16 ??g/L, respectively.
6.8.1.4.2 After the instrument is stable, use potassium borohydride-sodium
hydroxide solution as the reducing agent; USE hydrochloric acid solution as the
carrier solution; under the best working conditions of the instrument, measure
its fluorescence value. USE the measured fluorescence value as the ordinate;
USE the corresponding mass concentration of arsenic (??g/L) as the abscissa,
to draw a calibration curve and calculate the regression equation.
Note: When using an atomic fluorescence spectrometer for determination, the required
potassium borohydride solution concentration, carrier solution concentration, linear
range of calibration curves of various elements, pH value of sample solution, etc. will
vary depending on the model of the instrument. Users can, according to the
instrument model, choose the best test conditions.
6.8.1.5 Analytical procedure
6.8.1.5.1 Pre-cleaning of glassware
The glassware used in the test shall, before use, be soaked in nitric acid
solution (1+4) for 24 h; then rinsed with water for later use.
6.8.1.5.2 Sample determination
WEIGH about 1.5 g of liquid sample or 0.5 g of solid sample, accurate to 0.2
mg; PLACE it in a 100 mL beaker. ADD 30 mL of water, 1 mL of nitric acid
solution (1+1); COVER with a watch glass and boil for about 1 min. After cooling
to room temperature, transfer to a 100 mL volumetric flask; respectively add 5.0
mL of hydrochloric acid, 20 mL of thiourea solution; USE water to dilute to the
mark and shake well. Perform the determination according to the steps of
6.8.1.4.2 (if there is turbidity, use a medium-speed quantitative filter paper to
dry-filter before the determination). The arsenic content is obtained from the
calibration curve or regression equation.
6.8.1.6 Result calculation
The arsenic content is calculated as the mass fraction w4. The value is
expressed in %, calculated according to formula (7):
arsenic standard stock solution in a 100 mL volumetric flask; USE water to dilute
to the mark and mix well. Before use, pipette 10.00 mL of this solution into a
100 mL volumetric flask; USE water to dilute to the mark and mix well.
6.8.2.2.9 Lead acetate cotton.
6.8.2.3 Apparatus
6.8.2.3.1 Spectrophotometer: With a 1 cm absorption cell.
6.8.2.3.2 Arsenic detector: Comply with the provisions of 4.2.2.3 in GB/T 610-
2008.
6.8.2.4 Analytical procedure
6.8.2.4.1 Drawing of calibration curve
6.8.2.4.1.1 In 6 dry arsenic determination bottles, add 0.00 mL, 1.00 mL, 2.00
mL, 3.00 mL, 4.00 mL, 5.00 mL of arsenic standard solution in sequence; and
then add 30 mL, 29 mL, 28 mL, 27 mL, 26 mL, 25 mL of water in sequence; to
make the total volume of the solution be 30 mL.
6.8.2.4.1.2 ADD 20 mL of stannous chloride hydrochloric acid solution, 5 mL of
potassium iodide solution, and 1 mL of copper sulfate solution to each arsenic
determination bottle; SHAKE well. At this time, the acidity c (in terms of H+) in
the solution shall be between 1.8 mol/L and 2.6 mol/L. PLACE in a dark place
for 30 min~40 min; ADD 5 g of arsenic-free zinc granules to the arsenic
determination bottle. Immediately install the absorption tube, filled with lead
acetate cotton and containing 5.0 mL of silver diethyldithiocarbamate-
triethylamine trichloromethane solution (absorption liquid), on the arsenic
determination bottle; react for 25 min~35 min (Avoid direct sunlight. If the
absorption liquid volatilizes too fast, it shall pay attention to add
trichloromethane). TAKE off the absorption tube (do not suck the absorption
liquid backwards); USE trichloromethane to replenish the absorption liquid to
5.0 mL and mix well.
6.8.2.4.1.3 At a wavelength of 510 nm, use a 1 cm absorption cell; USE the
reagent blank as a reference; determine the absorbance.
6.8.2.4.1.4 USE the mass (mg) of arsenic as the abscissa; USE the
corresponding absorbance as the ordinate; DRAW a calibration curve, or
calculate a regression equation.
6.8.2.4.2 Determination
WEIGH about 10 g of liquid sample or 3.3 g of solid sample, accurate to 0.2 mg;
6.9.1.2 Reagents and materials
6.9.1.2.1 Nitric acid solution: 1+1.
6.9.1.2.2 Lead standard stock solution: 0.1 mg/mL.
6.9.1.2.3 Lead standard solution: PIPETTE 10.00 mL of lead standard stock
solution into a 1000 mL volumetric flask; ADD 20 mL of nitric acid solution; USE
water to dilute to the mark and shake well. 1 mL of this solution contains 1 ??g
of Pb.
6.9.1.3 Apparatus
6.9.1.3.1 Micro-liquid feeding device: Equipped with a button type 5 ??L~500 ??L
micro-liquid flowmeter or automatic sampler.
6.9.1.3.2 Electric heating atomic absorption analysis device: Electric heating
method. Reverse grounding compensation can be carried out.
6.9.1.3.3 Heating furnace: Made of graphite or high-temperature-resistant metal.
6.9.1.3.4 Lead hollow cathode lamp.
6.9.1.4 Analytical procedure
6.9.1.4.1 WEIGH about 10 g of liquid sample or 3.3 g of solid sample, accurate
to 0.2 mg. PLACE it in a 250 mL beaker; ADD 30 mL of water and 10 mL of
nitric acid solution. COVER with a watch glass and boil for 1 min. After cooling
to room temperature, transfer to a 250 mL volumetric flask; USE water to dilute
to the mark and shake well. This solution is test solution C.
6.9.1.4.2 Respectively pipette 0.00 mL (blank), 1.00 mL, 2.00 mL, 3.00 mL of
lead standard solution into four 50 mL volumetric flasks. ADD 1 mL of nitric acid
solution; USE water to dilute to the mark and shake well. USE a micro-liquid
feeding device to inject the prepared sample into the heating furnace; after
drying, ashing and atomization, measure the absorbance at 283.3 nm. USE the
mass concentration (??g/L) of lead standard solution as the abscissa; USE the
corresponding absorbance as the ordinate; DRAW the calibration curve and
calculate the regression equation.
6.9.1.4.3 PIPETTE an appropriate volume of test solution C; operate according
to 6.9.1.4.2, and determine. The mass concentration of lead is obtained from
the calibration curve or regression equation.
6.9.1.5 Result calculation
The lead content is calculated as the mass fraction w5. The value is expressed
6.9.2.2.7 Sodium diethyldithiocarbamate solution: 100 g/L.
6.9.2.2.8 Lead standard stock solution: 1 mL contains 0.1 mg of Pb.
6.9.2.2.9 Lead standard solution: PIPETTE 10.00 mL of lead standard stock
solution into a 100 mL volumetric flask; ADD 15 mL of nitric acid solution; USE
water to dilute to the mark and shake well. 1 mL of this solution contains 0.01
mg of Pb.
6.9.2.3 Apparatus
6.9.2.3.1 Atomic absorption spectrometer.
6.9.2.3.2 Lead hollow cathode lamp.
6.9.2.4 Analytical procedure
6.9.2.4.1 WEIGH about 5 g of liquid sample or 1.5 g of solid sample, accurate
to 0.2 mg. PLACE it in a 250 mL beaker; ADD 30 mL of water, 2 mL of nitric acid
solution; COVER with a watch glass and boil for about 1 min; and cool to room
temperature.
6.9.2.4.2 ADD 3 mL of ammonium citrate solution and 15 mL of ammonium
sulfate solution; USE aqueous ammonia solution or hydrochloric acid solution,
to adjust the pH value to 5.0~5.2 (use a pH meter). Then, respectively add 3
mL of sodium diethyldithiocarbamate solution and mix well.
6.9.2.4.3 After standing for 3 min, transfer to the separatory funnel.
Successively add 25.00 mL of 4-methyl-2...
Need delivered in 3-second? USA-Site: GB 15892-2020
Get Quotation: Click GB 15892-2020 (Self-service in 1-minute)
Historical versions (Master-website): GB 15892-2020
Preview True-PDF (Reload/Scroll-down if blank)
GB 15892-2020: Polyaluminium chloride for treatment of drinking water
GB 15892-2020
GB
NATIONAL STANDARD OF THE
PEOPLE?€?S REPUBLIC OF CHINA
ICS 71.100.80
G 77
Replacing GB 15892-2009
Polyaluminium chloride for treatment of drinking
water
ISSUED ON: JULY 23, 2020
IMPLEMENTED ON: AUGUST 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the PRC.
Table of Contents
Foreword ... 3??
1 Scope ... 4??
2 Normative references ... 4??
3 Molecular formula ... 5??
4 Product classification ... 5??
5 Requirements ... 5??
5.1 Raw material requirements ... 5??
5.2 Technical requirements ... 5??
6 Test methods ... 6??
6.1 General ... 6??
6.2 Determination of alumina (Al2O3) content ... 6??
6.3 Determination of basicity ... 12??
6.4 Determination of density ... 13??
6.5 Determination of insoluble matter content ... 14??
6.6 Determination of pH value ... 15??
6.7 Determination of iron content ... 15??
6.8 Determination of arsenic content ... 15??
6.9 Determination of lead content ... 20??
6.10 Determination of cadmium content ... 24??
6.11 Determination of mercury content ... 27??
6.12 Determination of chromium content ... 32??
7 Inspection rules ... 33??
8 Marking, packaging, transportation and storage ... 34??
Appendix A (Informative) Determination of coagulation performance ... 36??
Polyaluminium chloride for treatment of drinking
water
Warning - The strong acids and bases used in this Standard are corrosive.
During use, it shall avoid inhalation or contact with the skin. If splashed
on the body, it shall rinse immediately with plenty of water; in severe
cases, it shall seek medical attention immediately.
1 Scope
This Standard specifies the requirements, test methods, inspection rules,
marking, packaging, transportation and storage of polyaluminium chloride for
treatment of drinking water.
This Standard applies to polyaluminium chloride for treatment of drinking water.
The product is mainly used for the purification of drinking water.
2 Normative references
The following documents are indispensable for the application of this document.
For the dated references, only the editions with the dates indicated are
applicable to this document. For the undated references, the latest edition
(including all the amendments) are applicable to this document.
GB/T 191 Packaging - Pictorial marking for handling of goods
GB/T 320 Synthetic hydrochloric acid for industrial use
GB/T 601 Chemical reagent - Preparations of reference titration solutions
GB/T 602 Chemical reagent - Preparations of standard solutions for impurity
GB/T 603 Chemical reagent - Preparations of reagent solutions for use in
test methods
GB/T 610-2008 Chemical reagent - General method for the determination of
arsenic
GB/T 4294 Aluminium hydroxide
GB/T 6678 General principles for sampling chemical products
the excess EDTA solution, to get alumina (Al2O3) content.
6.2.1.2 Reagents and materials
6.2.1.2.1 Carbon dioxide-free water.
6.2.1.2.2 Nitric acid solution: 1+12.
6.2.1.2.3 Aqueous ammonia solution: 1+1.
6.2.1.2.4 Disodium ethylenediaminetetraacetic acid (EDTA) solution: c(EDTA)
is about 0.05 mol/L.
6.2.1.2.5 Acetic acid-sodium acetate buffer solution (pH=5.5): WEIGH 272 g of
sodium acetate (trihydrate) and dissolve it in water; ADD 19 mL of glacial acetic
acid; and dilute to 1000 mL.
6.2.1.2.6 Alumina standard solution: 1 mL contains 0.001 g of Al2O3. WEIGH
0.5293 g of high-purity aluminium (???99.99%), accurate to 0.2 mg. PLACE it in
a 200 mL polyethylene cup; ADD 20 mL of water; ADD about 3 g of sodium
hydroxide, to make it all dissolved and transparent (if necessary, heat on a
water bath). USE hydrochloric acid solution (1+1) to adjust to acidic and then
add 10 mL, to make it transparent, cool; TRANSFER to a 1000 mL volumetric
flask; DILUTE to the mark and shake well.
6.2.1.2.7 Zinc chloride reference titration solution: c(ZnCl2) is about 0.025 mol/L;
prepare as follows:
a) Preparation: WEIGH 3.5 g of zinc chloride (ZnCl2); DISSOLVE it in
hydrochloric acid solution [0.05% (volume fraction)]; DILUTE to 1 L and
shake well.
b) Calibration: PIPETTE 20 mL of EDTA solution and 40 mL of alumina
standard solution; PUT them in a 250 mL conical flask; follow the steps in
6.2.1.3 "ADD 10 mL of nitric acid solution..." to start the operation. READ
the consumption V (mL) of the zinc chloride reference titration solution. In
addition, pipette 20 mL of EDTA solution and place it in a 250 mL conical
flask. Follow the steps in 6.2.1.3 "ADD 10 mL of nitric acid solution..." to
start the operation. READ the consumption V0 (mL) of the zinc chloride
reference titration solution.
c) Result calculation: The concentration of zinc chloride reference titration
solution, c(ZnCl2), value expressed in moles per liter (mol/L), is calculated
according to formula (1):
Where:
V0 - The value of the volume of sodium hydroxide reference titration solution
consumed in the blank test, in milliliters (mL);
V - The value of the volume of sodium hydroxide reference titration solution
consumed for determination of the sample, in milliliters (mL);
c - The exact value of the actual concentration of sodium hydroxide reference
titration solution, in moles per liter (mol/L);
M - The value of the molar mass of hydroxide (OH-), in grams per mole (g/mol)
(M=16.99);
m - The value of the mass of the test portion, in grams (g);
w1 - The mass fraction of alumina measured in 6.2;
V1 - The value of the volume of test solution A pipetted, in milliliters (mL) (V1=25);
VA - The value of the total volume of test solution A, in milliliters (mL) (VA=250);
M1 - The value of the molar mass of aluminium, in grams per mole (g/mol)
(M1=26.98);
M2 - The value of the molar mass of alumina, in grams per mole (g/mol)
(M2=101.96).
6.3.5 Allowable difference
USE the arithmetic mean of the parallel determination results as the
determination result. The absolute difference of the parallel determination
results is not more than 2.0%.
6.4 Determination of density
6.4.1 Method summary
From the depth of immersion when the densitometer reaches the equilibrium
state in the measured liquid, read the density value.
6.4.2 Apparatus
6.4.2.1 Densitometer: The division value is 0.001 g/cm3.
6.4.2.2 Constant-temperature water bath: Controllable temperature (20??0.1)??C.
6.4.2.3 Thermometer: The division value is 0.1 ??C.
standard solution respectively in five 100 mL volumetric flasks. Respectively
add 5.0 mL of hydrochloric acid and 20 mL of thiourea solution; USE water to
dilute to the mark and shake well; PLACE for more than 30 min. The mass
concentrations of arsenic in this series of solutions are 0 ??g/L, 4 ??g/L, 8 ??g/L,
12 ??g/L, 16 ??g/L, respectively.
6.8.1.4.2 After the instrument is stable, use potassium borohydride-sodium
hydroxide solution as the reducing agent; USE hydrochloric acid solution as the
carrier solution; under the best working conditions of the instrument, measure
its fluorescence value. USE the measured fluorescence value as the ordinate;
USE the corresponding mass concentration of arsenic (??g/L) as the abscissa,
to draw a calibration curve and calculate the regression equation.
Note: When using an atomic fluorescence spectrometer for determination, the required
potassium borohydride solution concentration, carrier solution concentration, linear
range of calibration curves of various elements, pH value of sample solution, etc. will
vary depending on the model of the instrument. Users can, according to the
instrument model, choose the best test conditions.
6.8.1.5 Analytical procedure
6.8.1.5.1 Pre-cleaning of glassware
The glassware used in the test shall, before use, be soaked in nitric acid
solution (1+4) for 24 h; then rinsed with water for later use.
6.8.1.5.2 Sample determination
WEIGH about 1.5 g of liquid sample or 0.5 g of solid sample, accurate to 0.2
mg; PLACE it in a 100 mL beaker. ADD 30 mL of water, 1 mL of nitric acid
solution (1+1); COVER with a watch glass and boil for about 1 min. After cooling
to room temperature, transfer to a 100 mL volumetric flask; respectively add 5.0
mL of hydrochloric acid, 20 mL of thiourea solution; USE water to dilute to the
mark and shake well. Perform the determination according to the steps of
6.8.1.4.2 (if there is turbidity, use a medium-speed quantitative filter paper to
dry-filter before the determination). The arsenic content is obtained from the
calibration curve or regression equation.
6.8.1.6 Result calculation
The arsenic content is calculated as the mass fraction w4. The value is
expressed in %, calculated according to formula (7):
arsenic standard stock solution in a 100 mL volumetric flask; USE water to dilute
to the mark and mix well. Before use, pipette 10.00 mL of this solution into a
100 mL volumetric flask; USE water to dilute to the mark and mix well.
6.8.2.2.9 Lead acetate cotton.
6.8.2.3 Apparatus
6.8.2.3.1 Spectrophotometer: With a 1 cm absorption cell.
6.8.2.3.2 Arsenic detector: Comply with the provisions of 4.2.2.3 in GB/T 610-
2008.
6.8.2.4 Analytical procedure
6.8.2.4.1 Drawing of calibration curve
6.8.2.4.1.1 In 6 dry arsenic determination bottles, add 0.00 mL, 1.00 mL, 2.00
mL, 3.00 mL, 4.00 mL, 5.00 mL of arsenic standard solution in sequence; and
then add 30 mL, 29 mL, 28 mL, 27 mL, 26 mL, 25 mL of water in sequence; to
make the total volume of the solution be 30 mL.
6.8.2.4.1.2 ADD 20 mL of stannous chloride hydrochloric acid solution, 5 mL of
potassium iodide solution, and 1 mL of copper sulfate solution to each arsenic
determination bottle; SHAKE well. At this time, the acidity c (in terms of H+) in
the solution shall be between 1.8 mol/L and 2.6 mol/L. PLACE in a dark place
for 30 min~40 min; ADD 5 g of arsenic-free zinc granules to the arsenic
determination bottle. Immediately install the absorption tube, filled with lead
acetate cotton and containing 5.0 mL of silver diethyldithiocarbamate-
triethylamine trichloromethane solution (absorption liquid), on the arsenic
determination bottle; react for 25 min~35 min (Avoid direct sunlight. If the
absorption liquid volatilizes too fast, it shall pay attention to add
trichloromethane). TAKE off the absorption tube (do not suck the absorption
liquid backwards); USE trichloromethane to replenish the absorption liquid to
5.0 mL and mix well.
6.8.2.4.1.3 At a wavelength of 510 nm, use a 1 cm absorption cell; USE the
reagent blank as a reference; determine the absorbance.
6.8.2.4.1.4 USE the mass (mg) of arsenic as the abscissa; USE the
corresponding absorbance as the ordinate; DRAW a calibration curve, or
calculate a regression equation.
6.8.2.4.2 Determination
WEIGH about 10 g of liquid sample or 3.3 g of solid sample, accurate to 0.2 mg;
6.9.1.2 Reagents and materials
6.9.1.2.1 Nitric acid solution: 1+1.
6.9.1.2.2 Lead standard stock solution: 0.1 mg/mL.
6.9.1.2.3 Lead standard solution: PIPETTE 10.00 mL of lead standard stock
solution into a 1000 mL volumetric flask; ADD 20 mL of nitric acid solution; USE
water to dilute to the mark and shake well. 1 mL of this solution contains 1 ??g
of Pb.
6.9.1.3 Apparatus
6.9.1.3.1 Micro-liquid feeding device: Equipped with a button type 5 ??L~500 ??L
micro-liquid flowmeter or automatic sampler.
6.9.1.3.2 Electric heating atomic absorption analysis device: Electric heating
method. Reverse grounding compensation can be carried out.
6.9.1.3.3 Heating furnace: Made of graphite or high-temperature-resistant metal.
6.9.1.3.4 Lead hollow cathode lamp.
6.9.1.4 Analytical procedure
6.9.1.4.1 WEIGH about 10 g of liquid sample or 3.3 g of solid sample, accurate
to 0.2 mg. PLACE it in a 250 mL beaker; ADD 30 mL of water and 10 mL of
nitric acid solution. COVER with a watch glass and boil for 1 min. After cooling
to room temperature, transfer to a 250 mL volumetric flask; USE water to dilute
to the mark and shake well. This solution is test solution C.
6.9.1.4.2 Respectively pipette 0.00 mL (blank), 1.00 mL, 2.00 mL, 3.00 mL of
lead standard solution into four 50 mL volumetric flasks. ADD 1 mL of nitric acid
solution; USE water to dilute to the mark and shake well. USE a micro-liquid
feeding device to inject the prepared sample into the heating furnace; after
drying, ashing and atomization, measure the absorbance at 283.3 nm. USE the
mass concentration (??g/L) of lead standard solution as the abscissa; USE the
corresponding absorbance as the ordinate; DRAW the calibration curve and
calculate the regression equation.
6.9.1.4.3 PIPETTE an appropriate volume of test solution C; operate according
to 6.9.1.4.2, and determine. The mass concentration of lead is obtained from
the calibration curve or regression equation.
6.9.1.5 Result calculation
The lead content is calculated as the mass fraction w5. The value is expressed
6.9.2.2.7 Sodium diethyldithiocarbamate solution: 100 g/L.
6.9.2.2.8 Lead standard stock solution: 1 mL contains 0.1 mg of Pb.
6.9.2.2.9 Lead standard solution: PIPETTE 10.00 mL of lead standard stock
solution into a 100 mL volumetric flask; ADD 15 mL of nitric acid solution; USE
water to dilute to the mark and shake well. 1 mL of this solution contains 0.01
mg of Pb.
6.9.2.3 Apparatus
6.9.2.3.1 Atomic absorption spectrometer.
6.9.2.3.2 Lead hollow cathode lamp.
6.9.2.4 Analytical procedure
6.9.2.4.1 WEIGH about 5 g of liquid sample or 1.5 g of solid sample, accurate
to 0.2 mg. PLACE it in a 250 mL beaker; ADD 30 mL of water, 2 mL of nitric acid
solution; COVER with a watch glass and boil for about 1 min; and cool to room
temperature.
6.9.2.4.2 ADD 3 mL of ammonium citrate solution and 15 mL of ammonium
sulfate solution; USE aqueous ammonia solution or hydrochloric acid solution,
to adjust the pH value to 5.0~5.2 (use a pH meter). Then, respectively add 3
mL of sodium diethyldithiocarbamate solution and mix well.
6.9.2.4.3 After standing for 3 min, transfer to the separatory funnel.
Successively add 25.00 mL of 4-methyl-2...
Share











