MSPD/GPC-gc-NCI/MS法测定花生及其制品中68种
菊酯类农药残留方法的研究
气相色谱-质谱仪:Agilent 6890-5975,EI/NCI质谱检测器;R215旋转蒸发器(Buchi 公司)。MS1型涡流混匀器(IKA 公司);凝胶渗透色谱仪(GPC,德国LC Tech公司);T25型均质器(IKA公司)。
2.1.1固相萃取填料的选择
填料在基质固相分散中同时起着支持剂、吸附剂和净化剂的作用,待测农药在填料、洗脱液与样品基质之间进行吸附与分配,最终达到提取与净化双重效果,与单一的分散剂比较,C18+弗罗里硅土回收率较好,耗材成本较低。实验以200 μg/L甲氰菊酯作为标识物验证吸附填料在不同配比时的回收率.
采用C18和弗罗里硅土的重量比为2:1、1:1、1:2、1:4。分别称取2.00g装柱,添加1mL甲氰菊酯标准溶液,用30mL乙酸乙酯-环己烷(1:1)洗脱,计算回收率。结果显示,弗罗里硅土的加入可减少试样中糖类、蛋白质等强极性杂质的共洗脱,当C18和弗罗里硅土的重量比为1:2时,所得到的甲氰菊酯的回收率较高,且可与样品一起研磨后松散易装柱,因此实验选择C18和弗罗里硅土的最佳重量比为1:2。
均质提取法:分别称取2.00g粉碎的生花生仁和油炸花生仁试样于100mL具塞离心管中,加入15mL乙酸乙酯-环己烷(1:1),用10 000r/min均质提取2min, 加入5g NaCl,剧烈震荡10min,3 000rpm离心10min,取上层提取液于梨形瓶中,再重复提取一次,合并提取液,于40℃水浴旋转蒸发至近干,氮气吹干,备用。
基质固相分散萃取法:分别称取2.00g粉碎的生花生仁和油炸花生仁试样放入玻璃研钵中,添加500ng/mL的混合标准溶液100μL,加入2.00g的复合分散剂,研磨均匀至呈流体粉末状,装柱,压实。用30mL乙酸乙酯-环己烷(1:1)分5次洗涤研钵和钵锤,洗涤液再淋洗层析柱,流速约为1mL/min。收集洗脱液于梨形瓶中,并在40℃水浴中减压蒸发至约5mL,氮气吹干。以乙酸乙酯-环己烷(1:1)溶解梨形瓶中残渣,转移至10mL容量瓶中,并定容至刻度,备用。
图1 生花生经GPC与SPE净化后的gc-MS全扫描色谱图
Fig1. Full scan chromatograms of peanut kernel after purifying with SPE and GPC
Table2 Retention time(tR)and characteristic ions of 68 pyrethroids
No. | Compound | Retention time(min) | NCI-Quanlitative ion(m/z) | EI-Quanlitative ion(m/z) |
1 | Tefluthrin(七氟菊酯) | 9.98 | 241,205,243,242 | 177,178,197,199 |
2 | Bifenthrin(氟氯菊酯) | 30.34 | 386,205,387,241 | 181,165,166,182 |
3 | Fenpropathrin(甲氰菊酯) | 30.51 | 141,142,143,283 | 97,181,265,349 |
4 | Cyhalothrin-lambda(氯氟氰菊酯) | 31.61 | 241,205,243,449 | 181,197,208,209 |
5 | Cyhalothrin-gamma(氯氟氰菊酯) | 31.87 | 241,205,243,449 | 181,197,208,209 |
6 | Flumethrin(氟氯苯菊酯) | 33.64 | 283,285,247,249 | 59,72,337,320 |
7 | Deltamethrin(溴氰菊酯) | 37.65 | 297,217,295,299 | 181,253,251,255 |
8 | Permethrin-I(氯菊酯-I) | 32.77 | 207,209,354,390 | 183,165,163,184 |
9 | Permethrin-II(氯菊酯-II) | 32.97 | 207,209,354,390 | 183,165,163,184 |
10 | Cyfluthrin-I(氟氯氰菊酯-I) | 33.74 | 207,171,173,209 | 163,165,206,226 |
11 | Cyfluthrin-II(氟氯氰菊酯-II) | 33.90 | 207,171,173,209 | 163,165,206,226 |
12 | Cyfluthrin-III(氟氯氰菊酯-III) | 34.00 | 207,171,173,209 | 163,165,206,226 |
13 | Cyfluthrin-IV(氟氯氰菊酯-IV) | 34.09 | 207,171,173,209 | 163,165,206,226 |
14 | Cypermethrin-I(氯氰菊酯-I) | 34.24 | 207,209,171,173 | 163,165,181,201 |
15 | Cypermethrin-II(氯氰菊酯-II) | 34.41 | 207,209,171,173 | 163,165,181,201 |
16 | Cypermethrin-III(氯氰菊酯-III) | 34.53 | 207,209,171,173 | 163,165,181,201 |
17 | Cypermethrin-IV(氯氰菊酯-IV) | 34.61 | 207,209,171,173 | 163,165,181,201 |
18 | Fenvalerate(氰戊菊酯) | 35.94 | 211,213,212,214 | 125,167,181,419 |
19 | Esfenvalerate(高氰戊菊酯) | 36.38 | 211,213,212,214 | 125,167,225,419 |
20 | Fluvalinate-I(氟胺氰菊酯-I) | 36.40 | 294,296,502,295 | 250,252,251,502 |
21 | Fluvalinate-II(氟胺氰菊酯-II) | 36.54 | 294,296,502,295 | 250,252,251,502 |
22 | Acrinathrin(氟酯菊酯) | 32.19 | 333,334,305,167 | 181,208,289,247 |
23 | Tralomethrin(四溴菊酯) | 37.65 | 297,295,299,217 | 181,253,251,255 |
24 | Flucythrinate –I(氟氰戊菊酯–I) | 34.62 | 243,244,245,199 | 199,157,181,451 |
25 | Flucythrinate-II(氟氰戊菊酯-II) | 34.98 | 243,244,245,199 | 199,157,181,451 |
26 | Pyrethrins-pyrethrin- I (除虫菊酯- I) | 16.01 | 167,168,160,161 | 123,133,162,105 |
27 | Pyrethrins-pyrethrin- II (除虫菊酯- II) | 15.40 | 211,213,212,214 | 133,160,167,107 |
28 | Pyrethrins-jasmolin- I (瓦斯莫林- I) | 18.22 | 167,168,162,169 | 123,164,93,135 |
29 | Pyrethrins-jasmolin- II (瓦斯莫林- II) | 19.35 | 211,212,213,374 | 107,93,121,135 |
30 | Pyrethrins-cinnerin- II (瓜菊酯-I) | 17.80 | 167,168,148,169 | 123,150,121,93 |
31 | Pyrethrins-cinnerin- II (瓜菊酯- II) | 31.37 | 211,212,213,360 | 107,121,149,167 |
32 | Tetramethrin-I(胺菊酯-I) | 30.00 | 331,332,333,167 | 164,123,165,81 |
33 | Tetramethrin-II(胺菊酯- II) | 30.33 | 331,332,333,167 | 164,123,165,81 |
34 | Etofenprox(醚菊酯) | 19.62 | 177,198,199,362 | 163,164,135,183 |
35 | Allethrin(丙烯菊酯) | 14.69 | 167,168,134 | 123,79,107,136 |
36 | D-allethrin(D-丙烯菊酯) | 14.69 | 167,168,134 | 123,79,107,91 |
37 | Transallethrin-rich-d(d-富右旋反式烯丙菊酯) | 14.69 | 167,168,134 | 123,79,107,91 |
38 | Bioallethrin(生物丙烯菊酯) | 14.69 | 167,168,134 | 123,79,107,91 |
39 | Bioallethrin-S (S-生物丙稀聚酯) | 14.69 | 167,168,134 | 123,79,107,81 |
40 | Prallethrin(炔丙菊酯) | 9.01 | 167,132,168 | 123,81,105 |
41 | Phenothrin(苯醚菊酯) | 16.39 | 167,168 | 123,183,81,184 |
42 | Phenothrin-d-trans(苯醚菊酯-d-trans) | 18.64 | 167,168 | 123,183,81,184 |
43 | Cyphenothrin-I(苯醚氰菊酯) | 19.64 | 167,168 | 123,1F1,81,124 |
44 | Cyphenothrin-II(苯醚氰菊酯) | 20.36 | 167,168 | 123,181,81,124 |
45 | Rich-d-t-cyphenothrin-I(富右旋反式苯醚氰菊酯) | 20.66 | 167,168 | 183,123,184,81 |
46 | Resmethrin(苄呋菊酯) | 28.67 | 167,168 | 123,171,128,143 |
47 | Bioresmethrin(生物苄呋菊酯) | 29.08 | 167,168 | 123,171,128,143 |
48 | Transfluthrin(四氟苯菊酯) | 11.12 | 209,207,206,211 | 163,165,91,335 |
49 | Imiprothrin-I(炔咪菊酯-I) | 23.20 | 167,168,134 | 123,81,151,107 |
50 | Imiprothrin-II(炔咪菊酯-II) | 24.07 | 167,168,134 | 123,81,151,107 |
51 | Empenthrin-I(炔戊菊酯-I) | 8.89 | 167,132,168 | 123,91,107 |
52 | Empenthrin-II(炔戊菊酯-II) | 8.93 | 167,132,168 | 123,91,107 |
53 | Empenthrin-III(炔戊菊酯-III) | 9.01 | 167,132,168 | 123,91,107 |
54 | Silafluofen(氟硅菊酯) | 35.01 | 167,168,134 | 179,286,258,180 |
55 | Methothrin-I(甲醚菊酯-I) | 16.02 | 167,168 | 123,135,91,105 |
56 | Methothrin-II(甲醚菊酯-II) | 16.61 | 167,168 | 123,135,91,105 |
57 | Terallethrin(环戊烯丙菊酯) | 10.91 | 141,142,134 | 97,107,136 |
58 | Brofluthrinate(溴氟菊酯) | 31.87 | 243,244 | 199,157,207,184 |
59 | Chlorempenthrin-I(氯烯炔菊酯-I) | 10.50 | 207,209,171 | 91,107,163,105 |
60 | Chlorempenthrin-II(氯烯炔菊酯-II) | 10.80 | 207,209,171 | 91,107,163,105 |
61 | Furamethrin(炔呋菊酯) | 11.22 | 118,119,167 | 119,123,120 |
62 | D-t-furamethrin(D-右旋炔呋菊酯) | 11.40 | 118,119,167 | 119,123,120 |
63 | Dimefluthrin(四氟甲醚菊酯) | 15.64 | 166,167,168 | 123,81,176,124 |
64 | Pentmethrin-I(戊烯氰氯菊酯-I) | 11.12 | 171,207,173,209 | 163,108,165,91 |
65 | Pentmethrin-II(戊烯氰氯菊酯-II) | 11.54 | 171,207,173,209 | 163,108,165,91 |
66 | Pentmethrin-III(戊烯氰氯菊酯-III) | 11.70 | 171,207,173,209 | 163,108,165,91 |
67 | Pentmethrin-IV(戊烯氰氯菊酯-IV) | 11.97 | 171,207,173,209 | 163,108,165,91 |
68 | Halfenprox(卤醚菊酯) | 34.27 | 81,79,347 | 263,265,183,184 |
图2 菊酯类农药gc-EI-MS和gc-NCI-MS全扫描叠放图
Fig 2. Ful scan chromatogram of pyrethroids under NCI and EI mode
图3生花生仁基质溶液NCI和EI源gc-MS全扫描质谱图比较
Fig 3. comparison of ful scan chromatogram from NCI and EI in Peanut kernel
NO. | Pyrethroid | Peanut | |||||
0.005 mg/kg | 0.01 mg/kg | 0.05 mg/kg | |||||
Recovery R/% | RSD sr/% | Recovery R/% | RSD sr/% | Recovery R/% | RSD sr/% | ||
1 | Tefluthrin | 98 | 2.6 | 88 | 14.1 | 98 | 2.7 |
2 | Bifenthrin | 96. | 2.8 | 97 | 13.3 | 99 | 4.2 |
3 | Fnpropathrin | 96 | 1.6 | 93 | 9.9 | 98 | 2.2 |
4 | Cyhalothrin-lambda | 96 | 4.1 | 100 | 14.5 | 98 | 3.3 |
5 | Cyhalothrin-gamma | 97 | 3.1 | 97 | 8.4 | 98 | 5.5 |
6 | Flumethrin | 97 | 3.6 | 113 | 12.1 | 99 | 6.8 |
7 | Deltamethrin | 96 | 1.9 | 115 | 11.9 | 104 | 7.1 |
8 | Permethrin-I | 95 | 3.4 | 93 | 14.6 | 99 | 4.4 |
9 | Permethrin-II | 99 | 7.7 | 108 | 14.4 | 99 | 3.6 |
10 | Cyfluthrin-I | 97 | 2.5 | 112 | 9.7 | 101 | 5.3 |
11 | Cyfluthrin-II | 96 | 1.9 | 103 | 14.2 | 102 | 6.3 |
12 | Cyfluthrin-III | 97 | 5.3 | 103 | 12.6 | 103 | 6.8 |
13 | Cyfluthrin-IV | 95 | 3.7 | 95 | 8.8 | 102 | 7.0 |
14 | Cypermethrin-I | 96 | 3.8 | 87 | 6.0 | 96 | 3.3 |
15 | Cypermethrin-II | 97 | 1.1 | 85 | 6.4 | 97 | 1.7 |
16 | Cypermethrin-III | 94 | 1.6 | 78 | 9.6 | 98 | 2.2 |
17 | Cypermethrin-IV | 97 | 2.2 | 100 | 10.0 | 97 | 2.5 |
18 | Fenvalerate | 98 | 4.3 | 98 | 11.7 | 99 | 6.0 |
19 | Esfenvalerate | 99 | 4.0 | 107 | 14.9 | 97 | 3.1 |
20 | Fluvalinate-I | 97 | 3.1 | 85 | 13.2 | 97 | 4.8 |