8 2 Vol. 8 No. 2 2017 2 Journal of Food Safety and Quality Feb., 2017 * 李硕, 李莉, 曹进 (, 100050 ) 摘要 : 目的 (ethylenediaminetetraacetic acid disodium, EDTA-2Na) 方法, EDTA (Cu 2+ ),, Dikma C 18 (250 mm 4.6 mm, 5 μm), 30 1.0 ml/min 254 nm, ( 0.02 mol/l, 0.03 mol/l, ph=4): (80:20, V:V), EDTA-2Na (Bi 3+ ) EDTA-2Na 结果 20~400 μg/ml, 0.9995, 10 mg/kg (S/N=3), 95.8%~99.8%, RSD 1.3%~2.2% 结论 EDTA-2Na, (Bi 3+ ), (Fe 3+ ),,, EDTA-2Na 关键词 : ; ; ; Determination of ethylenediaminetetraacetic acid disodium in flour by high performance liquid chromatography LI Shuo, LI Li, CAO Jin * (National Institutes of Food and Drug Control, Beijing 100050, Beijing) ABSTRACT: Objective To establish a method for determination of ethylenediaminetetraacetic acid disodium (EDTA-2Na) in flour by high performance liquid chromatography (HPLC). Methods Analytes in the flour samples were extracted by sonication method. Copper ion with EDTA was formed in order to be determined by HPLC. The separation was carried out using a Dikma C 18 column (250 mm 4.6 mm, 5 μm) and the temperature was maintained at 30. The mobile phase consisting of water: methanol (80:20, V:V) was prepared by addition of tetrabutyl ammonium bromide (0.02 mol/l) and sodium acetate trihydrate (0.03 mol/l) followed by ph adjusted to 4.0 with phosphoric acid. The flow rate was optimized to 1.0 ml/min consideration of the resolution (2.0) and efficiency. Results The linearity range of this method was from 20 to 400 μg/ml with a correlation coefficient of 0.9995. The limit of detection (LOD) of copper(ii) ethylenediaminetetraacetic acid was 10 mg/kg (S/N=3), and the recoveries from spiked samples were 95.8%~99.8%, and RSD were 1.3%~2.2%. Conclusion To make the results more reliable, bisthum ion (Bi 3+ ) reagent is selected as a substitution of ferric ion (Fe 3+ ) to distinguish EDTA in flour. The method has been proved to be simple and sensitive and can be used as a reference method for determination of EDTA-2Na in flour. KEY WORDS: high performance liquid chromatography; ethylenediaminetetraacetic acid disodium; flour; food additive * 通讯作者 :,, E-mail: caojin@gmail.com *Corresponding author: CAO Jin, Researcher, National Institutes for Food and Drug Control, No 2, Tiantanxili, Dongcheng District, Beijing 100050, China. E-mail: caojin@gmail.com
640 8 1 引言 (ethylenediaminetetraacetic acid disodium, EDTA-2Na) GB 2760-2014 [1],,,,, [2] GB 2760-2014, 0.25 g/kg, ( 1), [1,3],,,, SN/T 3855-2014 GB/T 21234-2007, [4,5] - [6-16],, EDTA, - EDTA ( EDTA-Fe EDTA-Cu), EDTA EDTA (Cu 2+ ),, EDTA-Bi EDTA-Cu,,, 2 材料与方法 2.1 材料与试剂, 99.0%(Sigma-Aldrich ); (, Fisher Scientific ); (, ); 0.05 mol/l (ph=4.0), 0.006 mol/l, 0.006 mol/l, 0.006 mol/l ( ) 2.2 设备与仪器 Agilent 1260, ( ); Mettler AL204 ( ); FE20K ph ( ); KQ-3200DE ( ); CR22GIII () 2.3 色谱条件 : Dikma C 18 (250 mm 4.6 mm, 5 μm); : 30 ; : : ( 0.02 mol/l, 0.05mol/L, ph=4.0)=20:80 (V:V); : 1.0 ml/min; : 254 nm; : 20 μl 表 1 GB 2760-2014 规定的 EDTA-2Na 使用范围及限量 Table 1 Application fields and limitations of EDTA-2Na in GB 2760-2014 (g/kg) 04.01.02.05 0.07 04.01.02.08.03 () 0.25 04.02.02.03 0.25 04.02.02.04 0.25 04.02.02.05 ( ), 0.07 04.05.02.03 0.25 06.04.02.01 0.25 12.10 0.075 14.0 (14.01 ) 0.03
2, : 641 2.4 测定方法 2.4.1 标准溶液的配制 0.1 g, 0.0001 g, 10 ml,,, 1.000 mg/ml 0.10 0.20 0.50 0.75 1.0 ml 25 ml, 20 ml, 3 ml 20 mg, 0.05 mol/l 25 ml, 1 min, 0.45 μm, 20 40 100 200 300 400 μg/ml 2.4.2 样品处理 2.5 g, 0.0001 g, 25 ml, 20 ml, 400 W 5 min, 3 ml 20 mg, 0.05 mol/l 25 ml, 1 min, 5000 r/min 3 min, 0.45 μm, 3 结果与讨论 3.1 测定方法的选择,, (high performance liquid chromatography, HPLC), (EDTA) H 4 Y,, (Na 2 H 2 Y 2 ), H +, H 6 Y 2+,, 7 : H 6 Y 2+ H 5 Y + H 4 Y H 3 Y - H 2 Y 2- HY 3- Y 4- ; ph 1, H 6 Y 2+ ; ph 11, Y 4-, EDTA,, ( )EDTA 1:1 ( 1), EDTA EDTA, (lgk),, EDTA : Bi 3+ Fe 3+ Cu 2+ >Zn 2+ Al 3+ >Fe 2+ >Mn 2+ >K + >Ca 2+ > Mg 2+, 1 EDTA Fig. 1 Chelation of EDTA with metal cation 3.2 试验条件的选择 3.2.1 样品处理条件的确定 EDTA,,,,,,,, Fe 3+, Fe 3+ EDTA,,, Fe 3+ Fe 2+, Fe 3+ 3.2.2 确证试剂的选择 EDTA-Cu EDTA,, Fe 3+, Fe 3+, EDTA Bi 3+ EDTA-Bi EDTA-Cu, Bi 3+, EDTA-Bi EDTA-Cu EDTA, EDTA-Cu, EDTA-Cu ( 2), EDTA 3.2.3 ph 的选择, M EDTA MY lgk MY Cu 2+ Fe 3+ Fe 2+ Bi 3+ 4 lgk MY ph ( 3) ph 1~7, Cu 2+ Fe 2+ Bi 3+ lgk MY
642 8 ph, Fe 3+ lgk MY ph ph, Bi 3+ Cu 2+ lgk MY, Bi 3+ Cu 2+ EDTA, ΔlgK MY <6, Bi 3+ Cu 2+, EDTA-Bi EDTA-Cu, EDTA ph EDTA-Bi EDTA-Cu, ph=4.0, Cu 2+ EDTA,, a. ; b.; c. Bi 3+ a. positive sample; b. positive sample + EDTA; c. positive sample + Bi 3+ 2 Fig. 2 Confirmation of positive samples
2, : 643 3 Cu 2+ Fe 3+ Fe 2+ Bi 3+ lgk MY ph Fig. 3 Tendency of conditional stability constants (lgk MY ) for Cu 2+ Fe 3+ Fe 2+ and Bi 3+ at different ph values 3.3 方法学考察 3.3.1 线性范围, EDTA-2Na, 20 μl,, EDTA-2Na, : EDTA-2Na 20~400 μg/ml, Y=1.00299X-5.49893, (r) 0.9995 3.3.2 检出限与定量限 EDTA-2Na, (S/N)=3, (S/N)=10, 10 mg/kg 25 mg/kg 3.3.3 回收率与精密度 50 100 200 μg/ml 3, 6, 2, 3.4 实际样品测定, 48 EDTA-2Na, ( 3), 48 2 EDTA-2Na, 2 EDTA-2Na EDTA-2Na, GB2760-2014, EDTA-2Na,, EDTA-2Na,, EDTA-2Na a. ETDA-Cu ; b. ETDA-Cu Bi 3+ ; c. ; d. a. EDTA-Cu; b. EDTA-Cu + Bi 3+ ; c. blank sample; d. blank sample + EDTA-Cu 4 Fig. 4 Chromatograms of standard solutions and blank samples
644 8 表 2 Table 2 空白面粉样品中 EDTA-2Na 加标回收率的测定 (n=6) Recoveries of EDTA-2Na in blank flour samples (n=6) 50 μg/ml 100 μg/ml 200 μg/ml (μg/ml) RSD (μg/ml) RSD (μg/ml) RSD 1 47.1 94.2 98.4 98.4 201.1 100.6 2 46.9 93.8 97.6 97.6 196.5 98.3 3 48.1 96.2 94.2 94.2 198.2 99.1 95.8 2.2 96.8 1.8 4 47.4 94.8 96.1 96.1 197.7 98.9 99.8 1.3 5 48.2 96.4 98.7 98.7 200.9 100.5 6 49.8 99.6 95.8 95.8 203.3 101.1 Table 3 表 3 面粉样品中 EDTA-2Na 含量的测定 (mg/kg) Determination of EDTA-2Na in edible flour samples (mg/kg) EDTA-2Na EDTA-2Na EDTA-2Na EDTA-2Na 1 N/A 13 N/A 25 N/A 37 N/A 2 N/A 14 N/A 26 N/A 38 N/A 3 N/A 15 N/A 27 N/A 39 N/A 4 784.79 16 N/A 28 N/A 40 N/A 5 N/A 17 N/A 29 N/A 41 N/A 6 N/A 18 N/A 30 N/A 42 N/A 7 N/A 19 N/A 31 N/A 43 N/A 8 N/A 20 N/A 32 N/A 44 N/A 9 N/A 21 768.14 33 N/A 45 N/A 10 N/A 22 N/A 34 N/A 46 N/A 11 N/A 23 N/A 35 N/A 47 N/A 12 N/A 24 N/A 36 N/A 48 N/A : N/A 4 结论,,,, EDTA-2Na,,,, 参考文献 [1] GB 2760-2014 [S]. GB 2760-2014 National food safety standard for uses of food additives [S]. [2],,, (NaFeEDTA) [J], 2012, (1): 207 211. Xu ZM, Bao XD, Liu LL, et al. Research of domestic and overseas regulations of sodium iron EDTA [J].China Food Addit, 2012, (1): 207 211. [3] SN/T 2360.14-2009 14 : [S]. SN/T 2360.14-2009 Rules for the inspection of food additives for import and export-part 14: Flour treatment agents [S]. [4] GB/T21234-2007 [S]. GB/T21234-2007 Determination of sodium iron ( Ⅲ ) ethylenediaminetetraacetate, trihydrate (NaFeEDTA 3H 2 O) in iron fortified soy sauce [S]. [5]. ()[M]. :, 2000.
2, : 645 Wuhan University, Analytical chemistry (4th edition) [M]. Beijing: Higher Education Press, 2000. [6],,,. NaFeEDTA [J]., 2013, 34(18): 150 153. Di R, Huo JS, Wei F, et al. Determination of NaFeEDTA in soy sauce by HPLC [J]. Food Sci, 2013, 34(18): 150 153. [7],. NaFeEDTA [J]., 2008, 29(6): 308 311. Su WB, Lan RJ. Determination of NaFeEDTA in iron-fortified soy sauce [J]. Food Sci, 2008, 29(6): 308 311. [8],. [J]., 2000, 18(5): 445 447. Shi XX, Chen XM. Determination of EDTA residue in canned food products by RP-HPLC [J]. Chin J Chromatogr, 2000, 18(5): 445 447. [9],,. [J]., 2009, (6): 55 56. Huang J, Li WX, Huo JS. Determination of EDTA in fruit flavored beverage by RP-HPLC [J]. Food Food Ind, 2009, (6): 55 56. [10],,,. [J]., 2006, 24(1): 58 61. Wei F, Li WX, Huang J, et al. Determination of sodium iron ( Ⅲ) ethylenediaminetetraacetate in iron-fortified soy sauce by reversed-phase ion-pair high performance liquid chromatography [J]. Chin J Chromatogr, 2006, 24(1): 58 61. [11],,,. [J]. :, 2014, 50(6): 698 701. Wei DX, Han GY, Sun Y, et al. Determination of Na 2 -EDTA in food by HPLC-MS/MS [J]. Phys Test Chem Anal Part B: Chem Anal, 2014, 50(6): 698 701. [12],,. [J]., 2009, 19(3): 517 518. Lv XH, Wen H, Xu HQ. Determination of ethylenediaminetetraaceticacid disodium salt in canned chinese chestnut by high performance liquid chromatograph [J].Chin J Health Lab Technol, 2009, 19(3): 517 518. [13],,,. EDTA [J]., 2011, (2): 212 219. Zheng RX, Zhang X, Fang F, et al. Technical studies of detection method of EDTA residue in the pickled product [J].China Food Addit, 2011, (2): 212 219. [14],. [J]., 2014, (5): 5 10. Chen ZZ, Liu XG. Quality and technical supervision research [J]. Qual Technol Super Res, 2014, (5): 5 10. [15], 珅,,. [J]., 2013, 23(6): 50 53. Wei DX, Hu S, Sun Y. et al. Determination of EDTA-2Na in food by high performance liquid chromatography [J]. J Inspect Quarant, 2013, 23(6): 50 53. [16] SN/T3855-2014 [S]. SN/T3855-2014 Determination of ethylenediaminetetraacetic acid disodium in foodstuffs for export [S]. 作者简介 ( 责任编辑 : 杨翠娜 ) 李硕, 硕士, 主要研究方向为食品 化妆品检验及标准研究 E-mail: pahayokolide@sina.com 曹进, 博士, 研究员, 主要研究方向为食品安全检测 E-mail: caojin@nifdc.org.cn