GB/T 5009.139-2003 Determination of caffeine in beverages

This standard specifies the method for determining the caffeine content in cola-type beverages, coffee, tea and their products - ultraviolet spectrophotometry and high performance liquid chromatography (HPLC). This standard is applicable to the determination of caffeine in cola-type beverages, coffee, tea and their products. The detection limit of the ultraviolet method of this standard is: 3 mg/L for cola-type beverages; 5 mg/100g for coffee, tea and their solid products; 5 mg/L for liquid products of coffee and tea. The detection limit of the HPLC method of this standard is: 0.72 mg/L for cola-type beverages; 1.8 mg/100g for tea, coffee and their products. GB/T 5009.139-2003 Determination of caffeine in beverages GB/T5009.139-2003 Standard download decompression password: www.bzxz.net

TCS67.040
National Standard of the People's Republic of China
GR/T5009.139---2003
Previous to GB/1644-1396
Determination of caffeine in beverages
Determination of caffeine in beverages2003-08-11Promulgated
Ministry of Health of the People's Republic of China
Administrative Committee of Standardization of the People's Republic of China
Implementation on 2004-01-01
This standard replaces GB/11S34<-19568Determination of caffeine in beverages by micro-tablet method3. Compared with 3B/T16344-19%, this standard mainly modifies the following: B/15009.139-2C03---Compiled according to GB/20001.1-2001 standard Part 4, Chemical analysis method 3 The original structure of the standard has been changed. The Chinese name of the standard has been changed to the standard for caffeine in beverages. This standard was submitted by the Ministry of Health of the People's Republic of China. The drafting of this standard is mainly carried out by Shanghai Municipal Food and Drug Administration, Shanghai Institute of Health and Drug Control, and Huai Jin, the first drafter, He Guanma, Zheng Fang, Li Ranliang, the second drafter of this standard is Li Jingliang, Shi Manlin, and Chuang Qiu Mengxin. This is the first time that this standard has been issued in 2017. GH/T 5009.1392003
Caffeine (caffeine) is a yellow film compound with a chemical name of 13,3-diaminobenzaldehyde, which has stimulating effects on the brain and other micro-neurons, but it is addictive. For this reason, countries have formulated product hygiene standards for caffeine in beverages. The United States, Canada, Argentina, Japan, and the Philippines stipulate that the content of caffeine in beverages shall not exceed 20 mg/kg, and Yugoslavia stipulates that it shall not exceed 12 mg/kg. So far, my country only allows caffeine in alcoholic beverages, and its content shall not exceed 150 mg/kg. In order to strengthen food hygiene supervision and management, it is necessary to establish a standard method for the determination of caffeine. Ultraviolet spectrophotometry and HPLC (HPLC) are the methods for determining the caffeine content in alcoholic beverages, coffee, benzoic acid and finished products. 1. Scope: Determination of caffeine in beverages. GA/T5009.139—2003. This standard specifies the determination method of caffeine in cola-type beverages, coffee, steamed leaves and their products (UV spectrophotometry and high performance liquid chromatography (HPLC). This standard is applicable to the determination of caffeine in cola-type beverages, coffee, tea and their products. The detection limits of this standard are: 1.5 mg/L for soft coffee, 5 mg/100 for steamed leaves and their solid products, 1.8 mg/L for liquid coffee and tea products. The detection limits of this standard by HFLC method are: 72 ng/L for cola-type beverages, 0.8 mg/100 for tea, coffee and their products. Method 1: Spectrophotometry
2 Principle
The trichloroethylene solution of chlorinated chlorine has the maximum absorption at 275.5 μm, and the absorption value is proportional to the concentration, so it can be quantified.bZxz.net
3 Reagents
3. 7 Anhydrous sodium manganese.
3.2 Alkane or natural gas,
3.3 15g/L potassium permanganate solution: weigh 1.5g/L potassium manganate, dilute with water to 100ml.3.4 Sodium sulfite and chlorinated acid solution: weigh 11e anhydrous sodium sulfate, SO, and dilute with water to 100mL. Take another 1g of potassium hydroxide, dissolve it with water and dilute it to 100mL, then add about 3.515% slightly acidic acid, absorb 151ml. Place the acid in a 10T volumetric flask, add water and release oxygen for 3 hours, and add 20E hydrogen peroxide solution with water. After cooling, dilute to 100mL, and weigh 20% acetic acid solution with 3.7200/L acetic acid. Zinc [2e (CFI, C (0): 2HO add mT glacial acetic acid add water to crush and dilute the sample to 250m!
3.810Cg/L potassium chloride solution: weigh 00000 ferrous potassium chloride [Kte (CN). · 3H,] water to decompose and dilute to 1GmT..
3.9 Caffeine standard: content%, heart [. 3.10 Caffeine four standard reserve reduction, according to the standard Prepare 10.5 mL of iodine-containing solution with 4 mL of isoflurane and store in refrigerator. 5. Analytical procedures 5.1 Sample handling 5.1.1 Cola-type beverages: Accurately transfer 10.0 mL-20.0 mL of degassed cola solution to a 23-mL distilled water bucket. For the sample of the type recovery material, add 5ml.15g/L permanganate solution, mix. Weigh for 15min, add 1nml of the mixed solution. Mix. Add 50mL of dichloroethane. Mix for 100 times. Let stand for stratification. Collect chloroform. Add 100ml of water layer again. Distill chloroform. Mix for 15min. GB/T5009.139--2003. Let stand for 100min. 5.1.2 Coffee and its four forest samples: Take the coffee and its four forest samples and grind them into a uniform sample of less than 30 μg in a 100 ml beaker. Add 20 ml of water, cover, shake, and immerse for 2 h. After that, transfer the concentrated solution to a 0.10 ml volumetric flask, such as 2 ml. 200 8/T. Add 31.10% potassium ferrous sulfate solution, stir, mix well, make up to 100 ml with water, shake, and precipitate on a plate. 5.0 ml of the filtrate is 5.1.1. Prepare 100 μL monochloroethane for use. 5.1.3 Prepare a liquid sample of coffee or tea by transferring it into a 100 mL flask with a volume of 1.0-240 mL. Add 1.2 g of acid microparticles and shake well. If 2 mL of potassium ferrite is dissolved, shake to make up to 10 L. Keep the mixture still and remove 50 mL of the solution. Prepare 100 mL of 5.1.1. 5.2 Preparation of standard curve
Prepare the standard curve of 0.10 and 1.2 mg/m2 of coffee from distilled methane. Take 100 mg/m2 of coffee as the reference, adjust the zero point, and plot the light intensity at 276.5 nm in a colorimetric cup. Draw a linear regression equation based on the light-to-energy curve. 5.3 Add 5 mL of anhydrous sodium sulfate to a 10 mL test tube, add the sample of trichloroethane, and let it stand. Use a colorimetric cup to measure the absorbance at 276.5 nm. Based on the linear regression equation, the absorbance of the sample is calculated as g/m2 of coffee. At the same time, redistilled chloroform is used as a reagent blank, and the results are calculated according to the following formula: X = ()X 100 e199x100105 V, XmX1000 = (c-:) × 100 × 100 × 10 V + xVX1 00C
In Chinese:
7Clear density
can be used to reduce the amount of caffeine in the sample, the unit is grams per liter (g/00); the caffeine content in tea and its concentrated products, the unit is grams per liter [1.) The sample absorbance is the caffeine concentration, the unit is micrograms per milliliter (g/m. The reagent blank absorbance is equivalent to the internal concentration of coffee, the unit is micrograms per milliliter (/ml.): the average mass of the collected test sample, the unit is grams R
I take the volume of the sample, the unit is liter (mL); the volume of the water solution after the test sample is removed, the unit is milliliters (ml.)( )
Cola-type beverages, the absolute difference of two independent determination results obtained under the conditions of Anyoushi shall not exceed the arithmetic mean. Three: Add coffee, tea and its products: the absolute difference of two independent determination results obtained under the conditions of re-reaction shall not exceed the arithmetic half of 1,90
8 Principle
The second method High performance liquid chromatography HPLC)
GH/T5009.139—2003
With the non-solid alcohol, there is a certain amount of absorption at a wavelength of 26m: the size of the absorption value is proportional to the degree of coffee, so it can be quantified
9 Reagents
9.1 Methanol HPT.C reagent,
9.2 Acetyl fluoride FIILC test chrysanthemum,
9.3 Three kinds of alkanes: separate and purify, and remix if necessary, 9.4 Ultrapure water, 18.2 Mr,
9.5 Light water sulfuric acid material: analytical grade,
, 6 tert-butyl ether: analytical grade,
9.7 Caffeine standard product sieve size 8 or above. 10 Receivers and equipment
Xiaoshu chromatograph.
1.2 Chromatographic sample Hor6apC (30mx, 9mmid): 10.3 Pre-column RESAVFC8-
10.4 Production cleaning device (CQ250).
10.5 Fibrillated filter membrane
I1 Analytical steps
11.1 Sample treatment
11.1. Cola-type drink granules
11.1.1.1 Degassing. Reduce the sample and use an ultrasonic cleaner to ultrasonically remove it at 4℃ for 5min.11.1.1.2 Take 10.0mL of the degassed sample and pass it through a mixed microporous membrane, discard the top 5mL and keep the remaining 5mL for later use.11.1.2 Test non-tea leaves and their products. Take 2 pieces of crushed and less than 30 days old samples or commercial test files and put them into a 15VmL test tube, add 2mL-3mL of super-flowing water, then add 50Trl of chloroform, discard the first 30mL of 1mL of ultrasonic processor, and separate them. Pour the filtrate into another 150ml beaker, add another 5ul of trifluoromethane, repeat the above extraction steps, discard the sample, combine the first extracts, add a little anhydrous sodium saturated sodium fluoride and 5ml of saturated sodium fluoride, add to a 130ml volumetric flask, volume up to 100ml with trifluoromethane, take 10ml of the filtrate and proceed according to step 11.1.1.2. 11.2 Chromatographic conditions
11.2.1 Washing phase: methyl alcohol-ethyl alcohol-water = 57 + 29-14 (add 0.8 mA/[. acid per liter of pre-phase = 0 ml.) 11.2.2 Flow rate of mobile phase: 1.5 mL/min, 1.2.3 Inlet, cola beverage 13, mixed leaf coffee and its products 5.-2011.3 Standard cola preparation
Prepare standard cola concentrations of 0, 20, 50, 100, 150/mL Standard series, and then respectively inject 413L into 2863m2 of the sample and the net area, make the standard curve of area-coffee concentration or find the linear regression equation, 17.4 Determination
Take the cola drink 111. or coffee, tea set 10. Inject, measure its area at 386 - after adjustment according to the standard industry line (or linear regression equation), get the concentration of coffee solids equivalent to the peak area of ​​the sample: R/nT.), make the reagent empty, 231
GB/T 5009.139—2003
12 Result calculation
Caffeine content in cola-type ingredients (mg/100g) =
Coffee, tea and its finished products caffeine content (mg/100g) = c×V103/(×1000) In the formula,
The concentration of caffeine in the sample is obtained by using the standard curve, the unit is microgram per liter (g/L) Vtest volume, the unit is ml) sample volume, the unit is gram (g).
Auxiliary substances
Cola drinks: The absolute difference of the results of two independent tests obtained under the conditions of multiplexing shall not exceed 5% of the arithmetic mean; tea and its products: The absolute difference of the results of two independent tests obtained under the conditions of multiplexing shall not exceed 10% of the arithmetic half mean.2n2
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