GB 5009.93-2010

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GB 5009.93-2010	English	289	Add to Cart	3 days	National food safety standard -- Determination of selenium in foods	GB 5009.93-2010	Obsolete	GB 5009.93-2010

GB 5009.93-2010
National food safety standard.Determination of selenium in foods
National Standards of People's Republic of China
National Food Safety Standard
Determination of Selenium in Food
National food safety standard
Determination of selenium in foods
People's Republic of China Ministry of Health issued
Issued on. 2010-03-26
2010-06-01 implementation
Foreword
This standard replaces GB/T 5009.93-2003 "Determination of selenium in foods."
This standard replaces the standards previously issued as follows.
--GB/T 5009.93-2003;
--GB/T 12399-1996;
--GB 13105-1991.
National Food Safety Standard
Determination of Selenium in Food
1 Scope
This standard specifies the method for the determination of selenium in foods by hydride generation atomic fluorescence spectroscopy and fluorescence.
This standard applies to the determination of selenium in food.
2 Normative references
The standard file referenced in the application of this standard is essential. For dated references, only the edition date of the note
Apply to this standard. For undated references, the latest edition (including any amendments) applies to this standard.
The first method hydride generation atomic fluorescence spectrometry
Principle 3
After heating the sample by acid digestion, at 6 mo1/L HCl medium, the reduction of hexavalent selenium in the sample into tetravalent selenium, sodium boron hydride or boron
Potassium hydride as the reducing agent, the reduction of tetravalent selenium in the medium of hydrochloric acid into hydrogen selenide (H2Se), by a carrier gas (argon) into the atomizer into
Line atomization in selenium hollow cathode lamp illumination, the ground state of selenium atoms are excited to high energy state, the deactivation to the ground state, emitting a characteristic wave
Long fluorescence, and fluorescence intensity is proportional to the selenium content. Quantitative comparison with the standard series.
4 Reagents and materials
Unless otherwise specified, the reagents used in this method are analytically pure water GB/T 6682 provisions tertiary water.
4.1 Nitric acid. pure class distinctions.
4.2 perchloric acid. pure class distinctions.
4.3 hydrochloride. pure class distinctions.
4.4 mixed acid. nitric acid and perchloric acid of 9. 1 volume mix.
4.5 Sodium hydroxide. pure class distinctions.
4.6 a solution of sodium borohydride (8 g/L). Weigh 8.0 g of sodium borohydride (of NaBH4), was dissolved in sodium hydroxide solution (5 g/L), and then
The volume to 1000 mL, and mix.
4.7 ferricyanide (100 g/L). Weigh 10.0 g potassium ferricyanide [(K3Fe (CN) 6)], was dissolved in 100 mL of water, and mix.
4.8 selenium standard stock solution. Weigh 100.0 mg selenium (spectroscopically pure), was dissolved in a small amount of nitric acid, add 2 mL perchloric acid, boiling water bath
Heated 3 h ~ 4 h, after cooling plus 8.4 mL of hydrochloric acid, then cook in boiling water bath for 2 min, accurately diluted to 1000 mL, the concentration of hydrochloric acid
Of 0.1 mo1/L, the concentration of the stock solution is equivalent to 100 μg of selenium per milliliter.
4.9 selenium standard application solution. take 100μg/mL stock selenium standard solution 1.0 mL, the volume to 100 mL, this application concentration of 1μg/mL.
Note. You can also purchase the certified national standard element solution.
4.10 hydrochloric acid (6 mol/L). Measure 50 mL of hydrochloric acid (4.3) slowly added 40 mL of water, cool and dilute to 100 mL.
4.11 Hydrogen peroxide (30%).
5. Apparatus
5.1 atomic fluorescence spectrometer with selenium hollow cathode lamp.
5.2 Electric hot plate.
5.3 microwave digestion system.
5.4 Balance. a sense of the amount of 1 mg.
5.5 mill.
5.6 oven.
Step 6 Analysis
6.1 Sample Preparation
6.1.1 Food. The specimen was washed with water three times, at 60 ℃ drying, grinding, store in a plastic bottle and set aside.
6.1.2 vegetables and other plant foods. Take the edible portion washed with water with gauze to absorb water droplets, homogenised reserve.
6.1.3 Other solid samples. crushing, mixing spare.
6.1.4 Liquid Sample. Mix a