This standard specifies the method for determining rare earths by the spectrophotometric three-filter length method. This standard is applicable to the determination of rare earths in cereals, vegetables and fruits. The detection limit of this method is 0.1μg (5g sample). GB/T 5009.94-2003 Determination of rare earths in plant-based foods GB/T5009.94-2003 Standard download decompression password: www.bzxz.net

ICS 67.040
National Standard of the People's Republic of China
GB/T5009.94—2003
Replaces G3/T13.08-10pl
Determination of rare earths in vegetable fouds
Delerminatlon of rare earths in vegetable foudsPublished on August 11, 2003
National Health Commission of the People's Republic of China
Standardization Administration of China
Implementation on January 1, 2004bzxz.net
1i8/15009.94—2053
Replaces E/T13108—1SS1 Determination of rare earths in vegetable foods1. Compared with GB/T13108—1991, this standard has the following main changes: 1. The Chinese name of the standard has been changed to "Determination of rare earths in vegetable foods"! According to GB/122001.4-2001 Standard Abbreviation Rules, Part 1: Chemical Analysis Methods, the structure of the flavor standard has been modified. This standard was proposed and approved by the Ministry of Health of the People's Republic of China. This standard was drafted by the Food Industry Supervision and Inspection of the Ministry of Health, and the Chaoyang Provincial Health and Prevention Station, Ningjiao Food Supervision and Inspection Institute, Shanghai Food Safety Inspection Institute, Fujian Provincial Health and Prevention Station, and Fuzhou Food Safety Inspection Station participated in the drafting. The main drafter of this standard is Su Dezhao, from Sanzhou. The original standard was first made in 1999, and this is the first revision. 1 Standard Determination of rare earth in plant-based foods This standard is originally specified! The spectrophotometric method is used for rare earth source. This standard is applicable to the detection of rare earth in ten kinds of grains, fruits and vegetables. 1. Detailed description (Detailed description)
2. Terms and definitions
The following codes and definitions apply to this standard. 2.1
Rare earth [rare earth] General term for elements of the first and second groups of the periodic table, precious metals and their derivatives: 3. Principle
GB/T 5009.94-2003
When rare earth is mixed with ammonia K as a reagent, it will form a multi-component complex, FT3. The wavelength used is 68=66 nm-mm. The material should be accompanied by the light absorption value A=AA. The absorption value should be calculated or the absorption value should be A=AA. The material should be compared with the standard for quantitative determination. 4. 4. 1 Hydrochloric acid.
4. 2 Sulfuric acid.
4.3 Acid.
4.5 Hydrochloric acid drop: (T [C)Emal/Measure TGcml. Salt (2.1), dilute with water to 2Col.2.6 Acid solution: c (1/211) = 501/L, and collect 50ml of the solution (4.2) slowly add 239ml of water, cool and add 30ml of water
4.7 The whole solution: -/2H.S,)-3 nwL/L. Collect 1r 1.6imml/T. Acid solution: 1,> Add water to make sure it is diluted to 2c0 L4. 8 Acetic acid-solution: Use 36 42. Concentrated oxygenated water C℃ mL. Water 4, slowly add 5 Benzene Z degree, penetrate the world 15in calculate up to 2.3 water to 000m.
4.9 confirm base water field acid solution width (100/1.) take 10% micro-base water to break acid, add 50), water solution state solid point steel oxide adjust pH close to 2.3 need 2J 31 grains), typically use 1+1 nitrogen water or hydrochloric acid to adjust to pH3.8, 1 water dilute to 100L4.0 expansion main practice liquid (508/:: take 5R precipitation acid, use 90mL water after dissolution. Use 111% water or heat to adjust the concentration FJI3.3. Add water to dilute to 10gmL and prepare before use. 4.11 Benzoic acid brand (150/1.), take 15-mL arc, moisten with 5mL water. Add 1.5% hydrochloric acid solution) 151mL 1. Add 1mL ethanol while stirring continuously, dissolve with 1% water or 1mL HCl to 30% and add ethanol to 100mL. The liquid should be transparent without any precipitate. 4.12 Exhaustion point swelling normal-full healing K standard complex test (hereinafter referred to as III K reagent): urine, g/L The promotion plan swelling mountain water dissolved and 0./L of the coke K small book Wei. Mix in a volume ratio of +1:4.13 + standard solution, accurately weigh 1 dry 1), Pr, 0.., Nml, 0.Smg ((99.5% or more containing 571
GB/T5J09.94-2003
3.13 respectively into = small cups, 4m1 hydrochloric acid solution (4.51. Add water to the hot part [must be full of hydrogen peroxide ()] after a little training to remove the excess, each volume flask 2. Add water to the volume flask to the mark degree, this liquid contains 1.g olefins per house (calculated as oxides)
4.14 sieve F standard use rate drop: another collected diluted ten standard evaluation night (4.3) according to 0: (0.:1r0.,:Nd,:Sm0::0: ratio of 3.0% mixed medium transfer when the total oxides per year 5 nights
5.1 electric hot water silt
5.2 actual use electric furnace (thermostat)
5.3 suspected times, .5mL.
5.4 write short horse width 9,
5.5 and change the scale test; 10 mL.
5.6 Spectrophotometer
5.7 pII Il
5 Sample preparation
6. Cereals: except rice, pass through a sieve for 20 hours, and sieve. 6.2 Fruits: take edible parts, remove water, dry, crush and mix. If the sample cannot be tested immediately, it should be placed in a sealed container after 55 minutes, and the freshness ratio should be recorded. 7 Analysis steps
7.1 Sample treatment
7.1. Take various samples (5.1: with porcelain ash (5.3), add 5 l.6mal/1. single liquid (4,6>, better to cover, spread 0.5b to 1. (can be placed over the skin), evaporate to dryness on low heat: continue heating to carbonize until soon, put it in a high humidity furnace at 35 (keep it for 1h. At 50%./0,: 1. Raise the temperature to 500.=20, cool it to 11~6F, take it out after cooling, add 2ml. nitric acid, 1.3> moisture can be eliminated, then evaporate it and move it to 693 in a warm room. If necessary, repeat it again, take it out and cool it, add 2m=l/yi acid 4.52 hydrogen peroxide) water bath: do not drop it again, evaporate it again, use less water, select 10 degrees test (5, 5 and bring it to the extreme, keep it away from the most insoluble matter Or centrifuge: perform the soil test according to the method. 7.1.2 Weigh the vegetable and fruit samples 2)--30*(02), place in vitrified blood 15.8), add 10m1. sulfuric acid solution (1.7) overnight for 3.5h, and then steam for 1 hour. Then operate according to 7.2 to determine
7.1 standard loop
oh. 0.10, 0.241.0.60, 0.81.00 soil standard minus 14! 4 equivalent to 1,. Start, 1.0.2.0, 3., 1.00, 51 total weight respectively received 1 pre-doped 3m buffer 1. scale test intelligence (55), each add! mL magnetic field drop melt sensitive (1.s, ml. ascorbic acid storage liquid (4. [0) filter hook water to make up to about BmL, filter can be placed in 1 heart mia each north? l. Two Ping certificate liquid (, 11 immediately help evenly pass through the bright wash, then use 1ml, K network will (-1.), mud, 25 mn: see 3m, spectrometer: reverse the two zero points, respectively at the wave, = 63nm,; = 660. e4em measured Liu should set the light. Obtain the AA meter with the standard vertical coordinates, the dose time scale or as the coordinates of the preparation and curve: .2.2.0 = -4.1L with the reagent blank Ping Jun, created by the leading person %trL forging wash 4,
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