7 6 ol. 7 No. 6 016 6 Jornal of Food Safety and Qality Jn., 016 - 邹游 *, 蓝草, 欧阳少伦, 邵琳智, 林峰 (, 5106) 摘要 : 目的 - 方法 GB/T 88-008, CNAS-GL06: 006,, 结果 50 μg/kg,.70 μg/kg(k=), 结论, 关键词 : -; ; ; ; Uncertainty evalation for the determination of melamine resides in infant formla by liqid chromatography-tandem mass spectrometry ZOU Yo *, LAN Cao, OUYANG Shao-Ln, SHAO Lin-Zhi, LIN Feng (Inspection and Qarantine Technology Center, Gangdong Entry-Exit Inspection and Qarantine Brea, Gangzho 5106, China) ABSTRACT: Objective To evalate the ncertainty for the determination of melamine reside in infant formla by liqid chromatography-tandem mass spectrometry (LC-MS/MS). Methods Based on GB/T 88-008 Determination of melamine in raw milk and dairy prodcts, the original method to measre melamine reside in infant formla was improved. According to CNAS-GL06: 006 Gidance on evalating the ncertainty in chemical analysis, the sorces of ncertainty of the whole determination procedre were analyzed and calclated based on the mathematical model and fishbone diagram. Reslts When melamine reside in infant formla was 50 μg/kg, the ncertainty of measrement was.70 μg/kg (k=), and the major sorces of ncertainty of measrement were the calibration of LC-MS/MS, repeatability and measring deviation. Conclsions Standard crve fitting by internal standard method contribtes little in combined ncertainty, which is significant for conventional detection of melamine. KEY WORDS: liqid chromatography-tandem mass spectrometry; infant formla; melamine; internal standard method; ncertainty 基金项目 : (015GDK4) Fnd: Spported by Scientific and Technical Project of Gangdong Entry-Exit Inspection and Qarantine Brea (015GDK4) * 通讯作者 :,, E-mail: yo.zo@qq.com *Corresponding athor: ZOU Yo, Assistant Engineer, Inspection and Qarantine Technology Center, Gangdong Entry-Exit Inspection and Qarantine Brea, Gangzho 5106, China. E-mail: yo.zo@qq.com
46 7 1 引言,, [1] [],,,,, [],,,,,, [4] 009, GB/T 88-008 [5],, 材料与方法.1 仪器与试剂 QTRAP 4000 /(, AB SCIEX ); Analyst, UFLC-XR ( LC-0AD, SIL-0AC, CTO-0AC, ), BTS ( Sartoris ), 00 μl 1 ml (), HR-XC cc(60 mg)() ( 99.5%, Dr. Ehrenstorfer ); : Melamine- 15 N (TRC Inc.) (, ); (, Fisher ); (, Fisher ). 实验方法..1 标准溶液的配制 : 10 mg 5.00 ml, : 0.65 ml 5.00 ml, :.5 ml 5.00 ml, : 0~8, 70%.. 样品前处理 (1) :.00 g(±0.01 g), 50 ml,, 1 15 ml,, 5 ml, 5 min, 4 ml ml () : ml ml 0.1 mol/l, ml, ml 0.1 mol/l, 4 ml 5, () : 50, 0.75 ml, 1 min, 0.45 μm. 仪器条件 : Waters Atlantis HILIC Silica (4.6 mm x 100 mm, μm); 40 ; 5 μl; -5 mmol/l (8:, :); 5 min; 0.5 ml/min; (positive ions electrospray, ESI + ); (mltiple reaction monitoring, MRM) 结果与讨论,.1 建立数学模型 C D X f m f r, X:, μg/kg; C:, μg/ml; :, ml; m:, g; D:, D=10, ; fr:, 1; f Q :, 1. 不确定度来源及其评定, C; ; m ; fr; f Q :..1 标准曲线定量引入的不确定度 rel (c)..1.1 99.5%, U 0.5%,, 95% Q
6, : - 47 1 Fig.1 Graph of ncertainty component sorces, k B, : U 0.5% 1 0.5% k 1 0.5 1 rel 100% 100% 0.5% P 99.5..1. 0.01 mg 0.05 mg,, 95%, k 10 mg, B, : U 0.05 x 0.05 k 0.05 rel 100% 0.5% mx 10..1. () 5.00 ml : A ±0.00004 ml,, B, 0.00004 1 () 0.0000 0.0004, () = =5.000.0004=0.0060 ±, 0 0.0011-1,, 95% (K=)±(5.00 0.0011)=±0.08 ml, : 0.08 () 0.04 (): (1) () () rel 100% 0.17%..1.4 () 00 μl () 5.00 ml : 4容 rel 0.17% 00 μl : ±1. μl,, B, 1. 41 () ' 0.77 ±, 0 0.0011-1,, 95% (K=)±(100 0.0011)±0. μl, : 0. 4'() 0.17 (): 4(1) 4() 4移 rel 100% 0.79% (): rel 容 rel 移 rel 4 4 4 100% 0.80%..1.5 () 1000 μl () 5.00 ml : 5容 rel 0.17% 1000 μl : ±4.44 μl,, B,
48 7 5'(1) 4.44.56 ±, 0 0.0011-1,, 95%(K=) ±(500 0.0011)±1.65 μl, : 1.65 5'() 0.84 () : 5(1) 5() 5移 rel 100% 0.54% (): 容 移..1.6 5rel 5 rel 5 rel 100% 0.56% 00 μl (), : 6(1) 6() 6rel 100% 0.79%..1.7 5,, 1 Y=a+bX Table 1 表 1 最小二乘法拟合标准曲线结果 Reslts of the least sqares fitting standard crve x(μg/ml) x (μg/ml) y obs y 1 1.0 0.80744 0.80 1.97 0.69414 0.69467 5 5.00 1.6969697 1.6976 10 10..4468085.4519 0 19.9 6.61605 6.695 Y=0.1X+0.046 (r=0.9998) * x ; y obs ; y x, = 7.64 μg/kg, x : S( y) 1 1 x ( ) b P n n x i1 x i x x n yobs i1 y S( y) n, (x ): ; S(y): (); P: ; n: ; a: ; b: ; x : ; x : ; x i : ; y obs : ; y:, a=0.1, b=0.046, P=, n=6, x =5 μg/kg, S(y)=0.008, 7 =0.0189μg/kg, 7rel = 7 / x 100%= 0.0189 100% 0.47% 7.68 : rel 1rel rel rel 4rel 5rel 6rel 7rel () c 1.4%.. 样品称量的不确定度 rel (m)...1 GB/T 88-008 [6],,,... 0.01 g U m 0.0 g,, 95%, k,.00 g, B, : Um 0.0 ( m) 0.015 k m ( ) 0.015 rel ( m) 100% 0.75% m.00.. 重现性和偏差引入的不确定度 rel (f r )...1 0.5 μg/kg, 6 ( ).68 : ( f r 1) 100% 1.09% 6 : ( fr1) 1.09% rel( fr1) 100% 1.7% f 84.%... r1, 15 :
6, : - 49 表 三聚氰胺的加标回收率及相对标准偏差 (n=6) Table Recoveries and RSD of melamine (n=6) 1 4 5 6 f r1 /% /% /% 86.46 87.06 85.6 8.06 81.86 8.66 84..68 表 三聚氰胺标准添加回收率 Table Recoveries of melamine spiked 015.1.6 015.1.9 015..6 015..6 015.4.4 10.8 9.8 10.0 10.0 107.0 015.5.15 015.6.1015.7. 015.7.015.8.14 109.6 111.4 94. 100.4 98.4 015.9.8 015.10.1 015.11.6 015.11.6 015.1.17 101.6 104.4 108.4 106.5 109.8 ( f )/% r 104.4 (SD) 4.6 (RSD)/% 4.44 (f r ) 1.15 /% rel (f r )=( f )/ r f r 1.10 Table 4 表 4 信噪比结果 Reslts of signal to noise ratio 1 4 5 6 Z 0.581 0.611 0.594 0.575 0.561 0.60 z 0.588 rel ( fr ) rel (f r1) rel( fr) 1.67%..4 定容体积的不确定度 rel ()..4.1 00 μl 1. 00 μl (): 11 = () 0.77 = 0. (): () 1 0.17 : 1(1) 1() 1rel 100% 0.79%..4. 00 μl, : (1) () rel 100% 0.79%..4. 1000 μl 1000 μl : ±4.44 μl,, B, 4.44 1 ().56 ±, 0 0.000-1,, 95%(K=) ±(750 0.000)±0.45 μl, : 0.45 () 0. :
440 7 (1) () rel 100% 0.4% : rel 1rel rel rel () 1.16% [7]..5 液质仪器校准引起的不确定度 JJF 117-011- [6] 5 μg/l 5 g/l, 6, 5 μl, 4 s=0.0 A, B..6 ra 6 : 6 zj z s 1 1 j1 1 ra 100% 100% 6 z 6 61 z 0.0 1 100%.19% 6 0.588, z :, 6 ; z j : j ; j: ; S:..7 r (c) 5 μg/l 00 μl 5 μg/l 00 μl, : 8(1) 8() 8rel 100% 0.79% : 9rel =0.79% : r 1rel rel rel 4rel 5rel 8rel 9rel ( c) 1.54%..8 =5 μl ±0.015 μl,, B, 0.015 r ( ) 100% 0.17% 5..9 r (Hn) A, B,,, : rel ( fq) r Ar ( c) r ( ).68%. 不确定度分量列表,, 5 表 5 三聚氰胺测量不确定度分量表 Table 5 Measrement ncertainty component of melamine rel rel (c) 1.4% rel (m) 0.75% rel (f r ) 1.67% rel () 1.16% rel (f Q ).68%.4 相对合成标准不确定度 Xrel () c ( m) ( ) rel rel rel.70% [ ( f )] [ ( f )] rel Q rel r.5 相对扩展不确定度 95, k=, : U Xrel =k Xrel =.70%=7.40%.6 计算实例, LC-MS/MS 50 μg/kg, 50 μg/kg 7.40%=.70 μg/kg, 50 μg/kg ±.70 μg/kg 4 讨论, B,,,,,,,, -,
6, : - 441 Fig. Contribtion degree of measrement ncertainty component of melamine,, CNAS-GL06 [1] 7.1., 45, 0.74%,,, 6%,, 参考文献 [1]. CNAS-GL06: 006 [S]. China National Accreditation Service for Conformity Assessment. CNAS-GL06: 006. Gidance on evalating the ncertainty in chemical analysis [S]. [] JJF 1059-1999 [S]. JF 1059-1999 Evalation and expression of ncertainty in measrement [S]. [],,,. LC-MS/MS [J]., 01, 4(6): 475479. Chen Z K, Yang M C, L M, et al. Evalation of the ncertainty in determination of clenbterol hydrochloride reside in pork liver by LC-MS/MS [J]. Chin J Pharm, 01, 4(6): 475479. [4],,,. [J]., 011, 11(5): 79. Jin L, Shen LH, Cao XY, et al. HPLC method for the determination of melamine resides ncertainty in milk [J]. Sichan Anim et Sci, 011, 11(5): 79. [5] GB/T 88-008 [S]. GB/T 88-008 Determination of melamine in raw milk and dairy prodcts [S]. [6] JJF 117-001 -[S]. JJF 117-011 Calibration specification for liqid chromatography-mass spectrometers [S]. 作者简介 ( 责任编辑 : 姚菲 ) 邹游, 学士, 助理工程师, 主要研究方向为食品兽药残留及非法添加物分析 E-mail: yo.zo@qq.com