GB/T 17141-1997 Soil quality - Determination of lead and cadmium - Graphite furnace atomic absorption spectrophotometry
Some standard content:
ICS13.080
National Standard of the People's Republic of China
GB/T17141—1997
Soil quality-Determination of lead, cadmium-Graphite furnace atomic absorption spectrophotometry1997-12-08Promulgated
State Environmental Protection Agency
State Technical Supervision Bureau
1998-05-01Implementation
National Standard of the People's Republic of China
Soil quality
Determinition of lend, cadmium
Graphite furnace atomic absorption spectrophotometryGB/T171411997
Soil qualityDeterminalion of lend, cadmiumGraphite furnace atonic absorption spectrophotometry Spectrophotometry1 Subject content and scope of application
1.1 This standard specifies the graphite furnace atomic absorption spectrophotometry for the determination of sulfur and iron in soil fill. The detection limit of this standard (calculated by subtracting C5g of the sample solution to 5C:n) is: 1 mg/kg, 3.31 ng/kg. 1.2
The Zeeman method, self-absorption method and galvanometer method are used to deduct the background, and in the presence of matrix modifiers such as hydrogen ions or ammonium hydroxide, the trace amount of sulfur and iron in the sample is directly determined. 2 Principle
The mineral lattice of the soil is completely destroyed by the method of hydrochloric acid-nitric acid-hydrofluoric acid and perchloric acid digestion, so that all the test elements in the sample enter the test solution. Then, the test solution is injected into the graphite. After the pre-set drying, ashing, atomization and other heating procedures, the coexisting matrix components are evaporated and removed. At the same time, at the high temperature of the atomization stage, the lead and carbide compounds are dissociated into ground state atomic vapors, and selectively absorb the characteristic spectrum emitted by the hollow cathode lamp. Under the selected optimal measurement conditions, the absorbance of lead and carbide in the test solution is determined by back-test deduction. Unless otherwise specified, the reagents used in this standard are all analytical reagents that meet national standards and deionized water or hydrochloric acid (HCD) of equivalent purity, 2=1.19g/ml, and high-grade pure nitric acid (HNO). P
12g/ml. High-grade pure
nitric acid solution,
1+: use to prepare
nitric acid solution, volume fraction is 3%, use 3, prepare. Hydroxy acid (HF), °
perchloric acid (HCIO),
9 g/ml
168g/ml, high-grade
diammonium hydrogen phosphate ((NIL)) HPO) (high-grade pure) aqueous solution, weight fraction %. Shu standard stock solution, e.503mg/ml: accurately weigh .5023g (accurate to e.002g) spectral pure gold net in 50ml calcined 3.8
add 20ml nitric acid solution (3.3), dissolve under slight heat. After cooling, transfer to a 1600ml volumetric flask, dilute to the mark with water, shake the cup,
Jane standard stock solution, 9.500mg/ml: accurately weigh 8.5000g (accurate to 0.0002g) spectral pure diamond pot particles in 50.ml, add 20ml nitric acid solution (3:3), dissolve under slight heat. After cooling, transfer to 1900ml oxygen, dilute to the mark with water, burn it,
instrument, standard solution, lead 2804g/1, pin 5℃18/L: the standard reserve solution of aluminum and chain (3) (3.9) 3.10
is prepared by nitric acid solution (44) through level confirmation. 1997-07-30 approved
State Environmental Protection Agency
1998-05-01 implementation
GB/T171411997
General laboratory instruments and the following instruments.
Graphite furnace atomic absorption spectrophotometer (with background subtraction device). 4.3
Lead hollow lamp
Pin hollow lamp
Oxygen cylinder.
10 Manual sample injector
Instrument parameters
The maximum test conditions for different types of instruments are different. You can choose according to the instrument manual. The measurement conditions adopted by this standard are shown in Table 1.
Instrument measurement conditions
Band width (nm)
Band width (nm)
Lamp current (mA)
Dehumidification (t/s)
Charcoal flower (C/s)
Atomization (C/S)
Atomization (℃/s)
Metal gas (ml/min)
Atomic gas
Selection amount ()bzxZ.net
5 samples
80~00/20
80~1 50/33
500/20
263c/3
The collected soil samples (generally not less than 500g) are mixed and then divided into about 0.00 by quartering. After air drying (natural air drying or freeze drying), remove foreign matter such as stones and animal and plant remains from the sample, grind with a wooden stick (or agate stick), pass through 2mm nylon (remove sand larger than 1mm), mix and grind with a mortar until all the 2mm nylon sieve passes through 0.00 mesh (aperture 919m) nylon sieve, and then mix and set aside. 6
Analysis steps
Preparation of test solution
Accurately weigh 9.103g (accurate to c5002g) of sample in a ml polytetrafluoroethylene sieve. After moistening with water, add 5ml hydrochloric acid (3.\), heat at low temperature on the hot plate in the fume hood to make the sample initially decompose. When it evaporates to about 2~3ml, take it off and cool it slightly, then add 5ml nitric acid (3.2), ml oxynitric acid (3.6), 2ml perchloric acid (3.6), cover it and heat it at medium temperature on the hot plate for about 1 hour, then open the cover and continue to remove silicon by heat. In order to achieve a good desiliconization effect, the snail should be shaken frequently. When heated to emit thick white smoke of perchloric acid, cover it to fully decompose the black and white organic carbon compounds. After the black organic matter disappears, open the cover to drive out the self and steam until the contents become viscous. Depending on the decomposition situation, you can add 2m nitric acid (2.2), 2ml chlorofluoric acid (3.5), ml perchloric acid (3.6), and repeat the above decomposition process. When the white matter is almost gone again and the contents are viscous, remove the lid, rinse the lid and inner wall with water, and add 1ml nitric acid solution (3.3) to dissolve the residue. Then transfer the precipitate to a 25ml volumetric flask, add 3ml diammonium hydrogen phosphate solution (3.7), cool and make up to volume, and prepare for measurement. 2
GR/T17141—1997
Since there are many types of precipitates and the organic matter they contain varies greatly, pay attention to the digestion process. The digestion peak should be yellowish (with a higher content of precipitate), and there should be no obvious product precipitation. The quality of the electric heating mold is very high, and the absorbance of the solution should be determined according to the instructions. 6.3 Blank test
Use water to replace the sample first, and use the reagents (1) and the steps: the whole procedure is changed to dissolve and roll, and the identification is carried out according to the steps (). 6.4 Use the line to prepare more than 2 blanks and make the standard liquid (7): x, 2, 5.co,.In the ccmlml volume, add m3 hydrogen peroxide (3:3), and determine the concentration of lead (g/L). The solution contains 3, 0, and 0/1, and the content of lead (g/L) is calibrated in sequence under the conditions of low to high concentration. The absorbance of the calibrated bath gel is subtracted from the absorbance of the medium and the corresponding content (g/L) are plotted respectively. The results are expressed as follows: The content of lead (P, (ca), mg/k) in the chemical sample before calibration is calculated by the following formula: m
The absorbance of deep wave is used to identify the absorbance of the empty square test, and then the light mountain line is used to obtain the huge amount of the test, /1: Wuzhong:
wave through the real public machine, n mountain;
A frozen stock test column of the heavy market, many
test group of moisture content, %
B precision and accuracy
Multiple laboratories use different methods to analyze the lead in the SS series soil standard sieve. The precision and accuracy of the compilation are shown in the table. Table: Method precision and accuracy
Relaxative standard deviation
Lan Mian Zhou Zongzhu Nancha
Relative error
Appendix A (Appendix to the standard)
Determination of moisture content of soil samples
A1 Weigh 50 g of air-dried soil that has passed through a 1C8 mesh sieve (accurate to 0.01)), place it in an aluminum box or weighing box, and dry it in an oven at 165℃ for 2-53 hours until it reaches constant weight
The moisture content of air-dried soil expressed as a percentage is calculated as follows: A2
f (%)
Where: f
Moisture content of soil sample, %
-Weight of sample before drying, g
-Weight of sample after drying, g.
Additional remarks:
This standard is proposed by the Department of Science and Technology Standards of the State Environmental Protection Administration. This standard was drafted by China National Environmental Monitoring Center. The main drafters of this standard are Fang Wenqi and Liu Jing. This standard is interpreted by China National Environmental Monitoring Center.
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