GB/T 17139-1997 Soil quality-Determination of nickel-Flame atomic absorption spectrophotometry
Some standard content:
ICS13.080
National Standard of the People's Republic of China
GB/T 17139—1997
Soil quality-Determination of nickel-Flame atomic absorption spectrophotometry
Soil quality-Determination of nickel-Flame atomic absorption spectrophotometry1997-12-08Promulgated
State Environmental Protection Administration
National Technical Committee
1998-05-01Implementation
Subject content and scope of application
National Standard of the People's Republic of China
Soil quality—Determination of nickelFlame atomic absorption spectrophotometry
Soil quality—Determination of nickelFlame atomic absorption spectrophotometryThis standard specifies the method for determining the content of nickel in soil by flame atomic absorption spectrophotometry. 1.1
The detection limit of this standard (calculated by weighing: sample digestion and determination to 5cml) is 5mg/kg1.2
GB/T17139-1997
1.3.1 Use, m is used as an absorption line, and there are three lines with very close wavelengths. A narrower spectral band should be used to overcome it.
232.2nm is in the ultraviolet region. The light scattering and molecular absorption caused by salt particles and molecular compounds are relatively serious, which will affect the determination. The use of background correction can overcome this kind of interference. If the concentration allows, the test solution can also be diluted to reduce background interference. 2 Principle
The method of hydrochloric acid-acid oxygen-peroxy acid full decomposition is used to completely destroy the mineral lattice of the soil, so that all the elements to be measured in the test solution are passed into the test solution. After combustion, the soil digestion wave is sprayed into the air acetylene flame. At the high temperature at the beginning of the fire, the compound dissociates into ground state atoms. The ground state atom curtain produces selective absorption of the characteristic latent line 232.0mm emitted by the nickel hollow anode lamp. Under the selected most arbitrary measurement conditions, the absorbance is determined.
3 Reagents
Unless otherwise specified, the reagents used in this standard are analytically pure reagents that meet national standards and deionized water or hydrochloric acid (HCl) of equivalent purity
g/ml. Premium purity
HNO3: =ag/ml, premium purity. Nitric acid solution: Use 3 to prepare nitric acid solution with a volume fraction of 6.7%: 3.2 Prepare hydrofluoric acid (HF) p=149g/ml
perchloric acid (HCIO.), n=1/ml, high-grade pure 993mg/ml: Weigh 1.a00mg (accurate to 0.0002g) of spectrally pure powder into a 50ml beaker, nickel standard stock solution, add nitric acid solution (33) 2ml, warm. After it is completely dissolved, transfer the whole amount to a 180ml volumetric flask, dilute it with water to the mark, take the silver standard working solution, 5cmg/1: transfer nickel standard solution (3.7) c.5cml to a 2C3ml volumetric flask, dilute it with acid solution 3.8
(3.4) to the mark, shake well
General laboratory instruments and the following instruments,
Atomic absorption spectrophotometer (with background correction device). National Environmental Protection Agency
Approved on July 30, 1997
Implementation on May 1, 1998
Hollow lamp
In short use.
GB/T171391997
Air compressor, equipped with water removal, tea and dust collection devices. Instrument specification
The same type of instrument is the best test, and the instrument manual can be selected by yourself. Table 1 lists the three conditions commonly used in this standard.
Oxygen measurement conditions of the generator
Determination of shallow length n
Electric steam (A)
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5 Samples
Ten pieces of the sample (not less than 0.2) are mixed and then quartered to about 1 piece. After the pieces are dried (naturally air-dried or freeze-dried), the animal residues and other foreign objects are removed. After the cup (or maize), pass through the nylon sieve (remove the width of more than 2mm), and then grind it with agate. The sample is ground until it passes through a 103 mm (aperture 34 mm) sieve, and then mixed with a spoon for preparation of the analytical procedure. The sample is placed in a polytetrafluoroethylene sieve, and after being moistened with water, an acid (:) is added. The sample is heated at a low temperature in an electric heating tube in a plenum to decompose the sample. When the sample is about 3 minutes old, the condenser is removed, and then nitric acid (:), hydrogen peroxide (3), and perchloric acid () are added. The sample is covered and heated at a medium temperature on an electric heating plate for about 1 hour. Then the cover is opened and the heating is continued. In order to achieve a good effect, the sample should be shaken frequently. When the concentrated acid is heated, the black organic acid compound is decomposed. When the black substance is gone, lift the lid, and stir until the contents become viscous. Depending on the digestion performance, add more (3.2ml) fluoride, 1M perchloric acid (3.3ml), and repeat the above digestion process. When the contents become viscous, remove the lid, cool, wash the entire contents, add 1M chloric acid (3), and then transfer the contents to a 0ml bottle. After refrigeration, wash the entire contents, control the temperature, and measure the contents. The organic matter content is poor, and when it is not digested, pay attention to the test results. The digestion solution should be white or light yellow (with a higher content), and there should be no precipitation in the layer. When the electric heating method is not effective, it will multiply the amount by four times. 6.2
According to the instrument instructions, adjust the instrument to the best working conditions and determine the absorbance of the test. Blank test
Use deionized water as a sample, and use the same steps and reagents as 1: and each room is connected to the white room during the whole process. Perform a double determination. Each batch of samples is divided into 1 blank and 6.4 standard lines
Pipette the nickel standard solution into a 0ml volumetric flask with 3.30, 3.73, 2.5, #.03, 2.03, 3.03m.0ml volumetric flask and use 3, 3, 35mg/L. This standard should include nitric acid solution (..4) to make up to the mark. The standard is 5, 5.2, ., including the concentration in the test, the standard () is used to calibrate the change in the absorbance of the standard solution. 2
GB/T 17139-1997
Use the absorbance minus the blank to draw a calibration curve with the corresponding element content (mg/L). Expression of results
The nickel content (mg/kg) in the main soil sample is calculated according to the following formula: c+V
The absorbance of the test solution minus the absorbance of the blank test, and then the nickel content (mg/L) is found on the calibration curve; where:
V---the volume of the test solution (ml);
--the weight of the secret effect sample (g);
--the moisture content of the sample (%).
8 Precision and accuracy
The precision and accuracy of nickel in the ESS series soil standard samples analyzed by this method by multiple laboratories are shown in Table 2Table 2 Precision and accuracy of the method
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Experimental number
Guaranteed value
28:62.1.8
Total mean
Relative standard deviation in room
Relative standard deviation
Appendix A (table of standard deviation)
Determination of moisture content of soil sample
Weigh the soil sample that has passed the 3:1 wind T test Sample: ~9g (accurate to 0012), strict two Wangyi or weighing bottle, supply box 41
supply, ten
expressed as a percentage of the soil moisture content of the following formula: A2
(%) =
I:
soil sample moisture content, %:
before ten soil sample volume, K;
after ten + sample type, g.
Additional instructions:
This standard is the original knowledge of the Chinese environmental protection technology standard Sichuan Island China Environmental Monitoring Center responsible for the overall order. Six standards must exceed the grass people Liu Beijing, and the text piece, the East Huai main China Environmental Monitoring Center responsible for the interpretation of the road w
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