This standard specifies the determination method of parabens in food. This standard is applicable to the determination of parabens in soy sauce, vinegar, fruit juice and jam. GB/T 5009.31-2003 Determination of parabens in food GB/T5009.31-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.31—2003
Determination of p-hydroxybenzoic acid esters in foods2003-08-11Promulgated
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implementation on 2004-01-01bZxz.net
GH/T 5009.31-2003
This standard replaces the method for the determination of p-hydroxybenzoic acid esters in GB11672—5. The main revisions of the standard (/11721S) are as follows: The Chinese name of the standard is changed to Determination of the final level of extracts in foods; Part 4: Chemical analysis of the original standard. This standard is proposed by the Ministry of Health of the People's Republic of China and is subject to the supervision and inspection of sanitary feeding points, health inspection institutes, municipal health centers and epidemic prevention stations. This standard was first issued in 185 and revised for the second time in 1!15. 1.2
1 Scope
Determination of parahydroxybenzoates in foods
This standard specifies the content of parahydroxybenzoates in foods Determination of esters of hydroxybenzoic acid This standard is suitable for the determination of hydroxybenzoic acid esters in oil, vinegar, juice and jam. 2 Principle
CB/T5009.31-2003
After acidification, the hydroxybenzoic acid esters are extracted with acetaldehyde and separated and determined by gas chromatography with oxygen ionization detection. External standard method.
3 Test
Unless otherwise specified, all reagents used in this standard are analytically pure reagents.
3.1 Ethyl acetate, g/100 ml.
3.2 Anhydrous ethanol
3.3 Anhydrous sulfuric acid.
3.4 ​​Chlorinated solvent.
3.51 g/100 ml. Acidification,
3.61:1 Acid: 5 μm of acid, 100 μl of aqueous sample per day. 3.7 Standard solution of ethyl benzoate and lactone: accurately take ethyl hydroxybenzoate and lactone in 1:1 volume of 1:1 volume, and dilute the solution to the concentration of 1:1 of ethyl and propyl formate per ml with water. 3.8 Standard solution of ethyl benzoate and lactone: take appropriate standard solution of ethyl benzoate and propyl formate. Dilute with anhydrous ethanol to the concentration of 59, 10, 200, 400, 509 of ethyl formate and lactone per ml, respectively. 4.1 Gas chromatograph with hydrogen ionization detection, 4.2 KD concentrator.
5 Analysis step
5.1 Extraction and purification
10mL of 1:1 acetaldehyde and collected juice: homogenize the 23mL liquid in a funnel, add 1mL of 1:1 acid, 10mL of chlorinated compound and mix, add 7:57.53mL of ether once, add once for 2min, discard the water, put the combined acetaldehyde layer in a 250mL separation funnel, wash the whole funnel with 10mL saturated oxidizing agent solution of 1g/mL carbonate, wash twice with 50mL and 31.3mL of 1g/mL carbonate solution, and remove the water layer, ink the neck of the funnel with absorbent cotton, add 1C anhydrous sodium sulfate, and place in a chamber for 33min. In a KD energy box, remove the solvent by blowing, and discard the concentrated acetaldehyde layer with anhydrous ethanol containing 1g hydroxyethyl ester for gas chromatography. Weigh 5 g of pre-homogenized fruit juice into a 10 mL test tube, add 1 ml of 1.1% saline and 1.1 mL of sodium hydroxide solution, and extract three times with n.0.5 M ethyl acetate, each time for 7 min. Transfer the energy to 250 mL of a centrifuge and mix according to the following method:
5.2 Chromatographic conditions
5.2.1 Chromatographic column, 1.0 μm, inner diameter 2.5 μm, length 2.5 μm, containing 3% SE-3C fixed solvent. G) day ~ H month li1m253
GB/T5009.31—20C3
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522% signature TL gas mtmin academic gas cmln
sampling 1 Jiang standard series of various quality standards use Ding gas cabinet color trap, the actual network concentration of ethyl benzoic acid and ethyl benzoic acid sample quotient, with concentration as the horizontal axis, and the standard is drawn as the natural coordinate. 11. Determine the rate of change by the formula 11.5.4 Calculate the yield by comparing with the standard curve or standard curve:
5.4 Calculate the yield by the formula:
Ax1000
×1300
X is the amount of benzoic acid in the test sample or the unit is kg/kg; A
determine the mass of benzoic acid in the test sample, the unit is μl and P_
test volume, the unit is: V
test sample volume, the unit is μl (1.1 g)
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