This standard specifies the determination of nickel in food by graphite furnace atomic absorption spectrophotometry. This standard is applicable to the determination of nickel in various types of food. GB/T 5009.138-2003 Determination of nickel in food GB/T5009.138-2003 Standard download decompression password: www.bzxz.net

1C5 57.040
National Standard of the People's Republic of China
GH/T 5009.138—2003
Dai Mo GT/T18343—19
Deterrminalion of nickel in food
Deterrminalion of nickel in fods2003-08-11 Issued
Ministry of Health of the People's Republic of China
Standardization Administration of China
2004-01-01 Implementation
GB/T 5009, F38-2003
This standard replaces GB/T1684-19965 Nickel in Food and GR/T503.371591 Food Hygiene Standard 1.1.2 (applicable to margarine), GB13196-1994 Margarine Hygiene Standard Appendix 2 (limited to absorption spectrophotometry!).
This standard uses GB/T2001.4··29; Standard Part 4: Chemical Analysis Method 3 to expand the source standard.
This comprehensive standard is proposed by the Ministry of Health of the People's Republic of China. The first appendix of this standard is responsible for the quality of the unit, the provincial science and technology department of the Ministry of Health, Food Hygiene Supervision and Inspection Institute, such as the drafting unit: Beijing Jiansheng Road, Nanjing Railway Medical College, Beijing Municipal Health Commission. The two units that carry out this standard are: Shanghai Health Station, Dashi Bulletin Station, Anhui Provincial Health Station, Anhui Provincial Health Station, Chaonan Provincial Health Station, and Food Hygiene Supervision and Inspection Institute of the Ministry of Health. The logo of this standard is: G8/T5343—1556
CB/T5009.371985:GH/T5005.37
1996 Part:
GB13195—191 Part:
GR/T 5009.138—2003
Oil is an essential trace element for the human body, but excessive intake will cause harm to the human body. We have now formulated standards for edible oils and margarines. The standard methods are atomic mass absorption spectrophotometry and dione colorimetry, which have low sensitivity and do not meet the requirements of current food hygiene standards. This standard specifies the use of atomic absorption spectrophotometry to determine the content of food: this method is flexible and has little interference. In order to strengthen food hygiene supervision, it is very necessary to establish a standard determination method. 1 Scope
Determination of sodium in food
This standard specifies the determination of sodium in natural products by absorption spectrophotometry. This standard is applicable to the determination of sodium in various foods. The first method is atomic absorption spectrophotometry. 2 Method G8/T5009.139-20D3
The sample is digested and integrated into the absorption spectrophotometer. The electrothermal atom is added to 232.0Im. Its absorbance is proportional to the content or the range of the standard. Detection limit: 1.4g/m (linear range: g/.~100g/m.) 3 Reagents must be of high purity unless otherwise specified. 3.1 Nitric acid 3.211: Add 50 mL of nitric acid and dilute to 1.30,5°C/L nitric acid solution with water. 3.4: Pass through a sterilizing tube. 3.5: Ni standard stock solution: Collect 1.690R powder (9.9%) in 30 mL of 1+1 sodium hydroxide solution and heat to incubate. Transfer to 1 volumetric plate and add water and acetonitrile to the mark. This is equivalent to 1.R. 3.6: Use standard filter paper for staining. Prepare standard 1.30 mol/L nitric acid and prepare 200 g jars per liter. 4.2: Use a 4F atomic absorption spectrometer with a graphite and hollow pole lamp. 4.2: Use a high-pressure digestion (1 (H)I or 200 g).
4.3 Laboratory Equipment
5.1 Remove impurities such as grain and bean curd, and crush them. After 31 days, store them in a polyurethane container and keep them for later use. 5.2: Clean the new sample, dry it in a dry oven, take out the edible part, and cool it down every time. 6 Analysis Steps
6.1 Sample Digestion
6.1.1 Transfer the sample to a dry bottle with a size of 150 μm or 130 μm. Place the sample in a small bottle and place it in a sterile container. Place it on an electric heating plate with oxygen and add heat. Remove the heat and add 20% oxygen peroxide. Continue to heat the sterilization system. Add more oxidizing acid until the standard gas is no longer produced. Remove the water, reduce the boiling point and remove the excess. After the treatment, press the pressure for 11 seconds. Remove the radiator when the temperature reaches 10000. Remove the radiator when the temperature reaches 10000. Remove the radiator when the temperature reaches 10000. Remove the radiator when the temperature reaches 10000. Remove the digestion solution into a 1mF container, rinse the container with aliquots of water, and mix well. Perform the test. CE/T5009.138--2003
6.1.2 Commercial reagents
6.1.2.1 Take a sample of grain, bean, etc. 0.2%~1.2% concentration to 0.00%). Place it in a 715mT ethylene nitrate container, place it for a while, then add 1.5% hydrogen peroxide, put the container in a stainless steel jacket, seal the stainless steel jacket and the jacket tightly: in a constant temperature box, keep it in a constant temperature box for 2h~1b+ until the digestion is completed - naturally cool the whole room: transfer the digestion solution to a 25ml volumetric bottle, add a little or water several times, and transfer it to a container, adjust the volume to full scale, and divide it. Perform the empty test at the same time. 6.1.2.2 For meat, meat and other foods with high water content, use a charcoal mill to make a charcoal pulp, weigh 2.8~5% slurry (accurate to U ()) in four bottles of vinyl plastic, and place them in a HC ventilation box or a box until nearly ten, collect them, add 5:L nitric acid and leave them overnight, and then add ?mI. to oxidize them. 6.2 Preparation of standard series
Take the standard liquid (200ng/m0.501.U1.2.3..4.oml. in) r. volume and use c.5mol/L nitric acid Dilute to a certain depth, and then add 10% water. 6.3 Determination 6.3.1 Instrument conditions: Debug the spectrophotometer to the measurement state, test parameters: wavelength 232.0nm, wavelength 3.15nm, lamp current 4mA, dry drying 15u℃, 208+ ashing 1(aluminum Y:2)s, atomic force microscope 200 μm, 19, lamp or frequency calibration. 6.3.2 Sample determination: Place the blank solution, nickel standard solution and digested sample solution into a furnace for determination, and add 20L of sample. 6.4 Result calculation According to calculation:
Wu,
X AxyxIcus
m×1100
X——Lithium content in the sample, expressed in grams per gram (ng/kg)A: Gold content in the test solution, expressed in nanograms per milliliter (mL)A: Content of blank solution, expressed in nanograms per milliliter (K/ml)V: Test volume, expressed in grams (kg)
7 Precision measurement
Under the repeatability system, the difference between two independent determination results shall not exceed the arithmetic mean. The average value of the "heart light". The second method is colorimetric method. 8 Principle. After the sample is extracted with a dye, persulfate is used as an oxidant in a mechanical solution to form a red complex with diacetyl. Compared with the standard series, it is determined: 9 Reagents. 9.1 Take 1mL of the whole and add water to 96mL. 9.2 Sodium hydroxide. Boiling range 30℃~-60℃. 9.3 Sodium hyaluronate is dissolved (100) 81.). 9.4 Phenol red indicator (1 g/1): weigh 0. [g red and dissolve it in ethanol (20%) and dilute it to 100 m]. 9.5 Nitrogen water:
9.6: Dihydrogen nitrate (1g/L)
9.7 Three bottles of methane. bZxz.net
9.8 Water (1+10)
9.9 Potassium tartrate (530g):
9.10 Oxidation solution 95E):
9.11 Dissolve as much as possible (6g-L) GB/T5009.138-2003
9.12 Standard shrinkage: Accurately weigh 1! Silver powder or 0.495 potassium bis(IV)[NV·iEF, add a small amount of 1+1300 volumetric bottle with 100% acid (1+23 dilute the sample to the required concentration): Note: 109.0 pieces are not included. 9.13 The standard charcoal is concentrated to 1.3 mL and then replaced with standard liquid in a 100 mL vial. The solution is diluted with acid (1% diluted). This is equivalent to 1.0%. The instrument is pre-drummed with nitric acid (1% diluted) for 1 hour. Rinse thoroughly with water. 10.1 Electric oscillator. 10.2 minutes of light collection
11 Analysis step
11. Sample treatment
Take 55.00 of the sample that has been heated in water and put it into a 125-well empty bottle, put it in a 230℃ bath, heat it for 30 minutes, vibrate it in a heat exchanger for 1 minute, wait for the gas layer and the water layer to separate, pour it into a centrifuge for 25 minutes, let it stand and separate, then put the water layer into the second centrifuge, and the oil layer into the original bottle: add salt (water bath, heat it for 5 minutes, and then dissolve it in water for 10 minutes, and then put it into the first centrifuge, and put the water layer into the first centrifuge. , discard the oil layer. 11.2
Put the second liquid separator under the bucket or keep the extract cold, add 15ml of blue, and drag it to the bottom! The layers are separated and then adjusted. 11.3
Add 3 drops of indicator liquid to the extract, 5ml of warm sodium ion, 105/L) ammonia water, make the solution turn from white to yellow and then red, then add 3~4 drops to make the pH of the solution S.5--JC. Then add? mT. Ding foot·ethanol 1Gg/I.. shake finger: min, extract with 2 mL of 1% chloroform in 50% water 1/3 0.5 mL each time (3 times || tt || 2.5 mL, return to the solution and filter into 1% ethanol, discard the 2% ethanol, and collect the required acid solution in 10 mL. Colorimetric analysis. || tt || 0.0.50, 1.3.2.0, 3.0, 4.0. 5.0mL of the test solution (C.0.50.1.0, 2, 5.3, 0.1.0.5, 3 points) were added to the colorimetric solution of 10 plugs, respectively, and aldehyde (1 ten) was added to m. In the sample and standard, 1.3mL of potassium sodium tartrate was added (500gL), 1.51. Hydrogenated hook braid was added (100/L): 1.5rl. Persulfate solution [5/1) was distributed and placed in Ir, 2n:1. Ding surface number-ethanol solution (1Cg, 1.1 water to 10 m, flow, etc. After 15n of gel, use a 1cm colorimetric cup, adjust the equal point with this, and change to 470 yuan: create a photometric, draw a standard screen line for comparison. : r.5 Jing Result Calculation
According to formula (2):
Rong:
Test light content, single test for the rate of investigation of the explosion point mg/g12)
GB/T5009.13B—2003
A——— Determination of the mass of nickel sample: unit is very gram (): agent——-sample mass, unit is gram.g). The calculation result is indicated to the necessary significant figures. 12 Precision
The absolute value of the two independent determination results obtained under sub-complex conditions shall not exceed 10% of the arithmetic mean, 18-1
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