| Literature DB >> 35478006 |
Ruihan Xu1, Qianwen Xie1, Xujun Li2, Hongli Zhao3, Xuebin Liu4, Yuanlong Wei5, Aidong Qiu6.
Abstract
A modified QuEChERS method, based on multi-walled carbon nanotubes (MWCNTs), was established for the detection of 10 pyrethroid pesticides (cyfluthrin, flucythrinate, fenpropathrin, bifenthrin, cyhalothrin, permethrin, cypermethrin, etofenprox, fenvalerate, deltamethrin) in tea, in combination with gas chromatography-tandem mass spectrometry (GC-MS/MS). The purification effects and dosages of four carbon nanomaterials, viz. single-walled carbon nanotubes (SWCNTs), MWCNTs, amino-modified MWCNTs, and graphene, were compared. An orthogonal experimental design was used to determine the optimal experimental conditions for sample pretreatment. The experimental factors governing the process were analyzed using variance. The results showed that the optimized sample pretreatment parameters were as follows. Acetonitrile was used as the extraction solvent with ultrasonic extraction for 35 min, while 60 mg MWCNTs, 200 mg PSA, and 200 mg C18, were used as purifiers. The effects of the extraction solvent and the carbon nanomaterials used on the recoveries of the 10 pyrethroid pesticides were significantly different (p<0.001), and the effect of extraction time on the recoveries was statistically different (p<0.05). The dosage of carbon nanomaterials had no significant effect on the recoveries (p>0.05). Good linearities were observed for the 10 pyrethroid pesticides in the concentration range of 0.01-2 mg/L. The limits of detection (LODs) and limits of quantification (LOQs) were in the ranges of 0.001-0.01 mg/kg and 0.005-0.04 mg/kg, respectively. The average recoveries of the pyrethroid pesticides spiked into blank samples of green tea were 91.4%-109.7%, and the relative standard deviations were 0.12%-9.80% (n=6). Furthermore, the matrix effects (MEs) of scented green tea, green tea, and black tea were evaluated. It was found that the addition of MWCNTs to the purifier can effectively reduce the matrix effect in green tea and black tea matrices. The developed method and the national standard method were used to detect the residues of the 10 pyrethroid pesticides in 120 tea samples available in the market. The results showed that cyfluthrin, deltamethrin, fenvalerate, permethrin, fenpropathrin, cypermethrin, bifenthrin and cyhalothrin were detected, and the contents obtained with the two methods were similar. Although pyrethroids were detected in most tea samples, the contents of all pesticide residues were below the maximum residue limits (MRLs). Therefore, the developed method is suitable for the rapid quantitative analysis of pesticide residues in tea.Entities:
Keywords: gas chromatography-tandem mass spectrometry (GC-MS/MS); matrix effect (ME); multi-walled carbon nanotubes (MWCNTs); pyrethroid pesticides; tea
Mesh:
Substances:
Year: 2022 PMID: 35478006 PMCID: PMC9404200 DOI: 10.3724/SP.J.1123.2021.11015
Source DB: PubMed Journal: Se Pu ISSN: 1000-8713
10种拟除虫菊酯类农药的GC-MS/MS分析参数
| Compound | Quantitative | CE/ | Qualitative ion pairs | CEs/ |
|---|---|---|---|---|
| Cyfluthrin | 198.9>170.1 | 25 | 162.9>127.0; 162.9>90.9 | 5; 15 |
| Flucythrinate | 156.9>107.1 | 15 | 156.9>77.0; 198.9>157.0 | 35; 10 |
| Fenpropathrin | 181.1>152.1 | 25 | 264.9>210.0; 207.9>181.0 | 10; 5 |
| Bifenthrin | 181.2>165.2 | 25 | 181.2>166.2; 166.2>165.2 | 10; 20 |
| Cyhalothrin | 197.0>141.0 | 10 | 208.0>181.0; 197.0>161.0 | 5; 5 |
| Permethrin | 183.0>77.1 | 35 | 184.0>169.1; 183.1>168.0 | 15; 20 |
| Cypermethrin | 163.0>91.0 | 10 | 163.0>127.0; 164.9>91.0 | 5; 10 |
| Etofenprox | 163.0>107.1 | 20 | 183.1>168.0; 376.0>163.1 | 5; 25 |
| Fenvalerate | 167.0>125.1 | 5 | 224.9>119.0; 208.9>141.1 | 15; 15 |
| Deltamethrin | 252.9>93.0 | 15 | 252.9>174.0; 250.7>172.0 | 5; 5 |
CE: collision energy.
图1提取溶剂对各目标农药回收率的影响(n=3)
图2超声提取时间对各目标农药回收率的影响(n=3)
图34种碳纳米材料及其用量对各目标农药回收率的影响(n=3)
QuEChERS法正交试验设计因素水平表
| Level | Factors | |||
|---|---|---|---|---|
| A | B | C | D | |
| 1 | acetonitrile | 20 | SWCNTs | 30 |
| 2 | acetone | 35 | MWCNTs | 60 |
| 3 | ethyl acetate | 50 | amino modified | 90 |
| MWCNTs | ||||
QuEChERS法L9(34)正交试验设计实验结果及极差分析结果
| No. | Columns | Average | ||||||
|---|---|---|---|---|---|---|---|---|
| A | B | C | D | |||||
| 1 | 1 | 1 | 1 | 1 | 89.5 | |||
| 2 | 1 | 2 | 2 | 2 | 99.0 | |||
| 3 | 1 | 3 | 3 | 3 | 89.0 | |||
| 4 | 2 | 1 | 2 | 3 | 85.3 | |||
| 5 | 2 | 2 | 3 | 1 | 81.4 | |||
| 6 | 2 | 3 | 1 | 2 | 80.9 | |||
| 7 | 3 | 1 | 3 | 2 | 84.3 | |||
| 8 | 3 | 2 | 1 | 3 | 84.7 | |||
| 9 | 3 | 3 | 2 | 1 | 85.6 | |||
|
| 277.5 | 259.1 | 255.1 | 256.5 | ||||
|
| 247.6 | 265.1 | 269.9 | 264.2 | ||||
|
| 254.5 | 255.5 | 254.6 | 259.0 | ||||
|
| 92.5 | 86.4 | 85.0 | 85.5 | ||||
|
| 82.5 | 88.4 | 90.0 | 88.1 | ||||
|
| 84.8 | 85.2 | 84.9 | 86.3 | ||||
|
| 10.0 | 3.2 | 5.1 | 2.6 | ||||
| Order | A>C>B>D | |||||||
| Optimal level | A1 | B2 | C2 | D2 | ||||
QuEChERS法多因素方差分析结果
| Source | Type Ⅲ sum | df | Mean | Sig. | |
|---|---|---|---|---|---|
| A | 491.53 | 2 | 245.76 | 49.30 | 0.000*** |
| B | 46.79 | 2 | 23.40 | 4.69 | 0.023* |
| C | 150.03 | 2 | 75.02 | 15.05 | 0.000*** |
| D | 31.26 | 2 | 15.63 | 3.14 | 0.068 |
| Error | 89.73 | 18 | 4.99 | ||
| Total | 809.35 | 26 |
*: p<0.05 implies a statistical difference.
***: p<0.001 implies a very significant statistical difference
图4不同含量的目标农药在绿茶、红茶、花茶3种茶叶基质中的基质效应
绿茶中各目标农药的线性范围、相关系数、检出限和定量限
| Compound | Linear equation | Linear range/ | LOD/ | LOQ/ | GB 23200.113-2018 | ||
|---|---|---|---|---|---|---|---|
| Cyfluthrin | 0.9998 | 0.01-2 | 0.01 | 0.03 | 0.05 | ||
| Flucythrinate | 0.9997 | 0.01-2 | 0.005 | 0.01 | 0.05 | ||
| Fenpropathrin | 0.9994 | 0.01-2 | 0.002 | 0.005 | 0.05 | ||
| Bifenthrin | 0.9994 | 0.01-2 | 0.001 | 0.005 | 0.05 | ||
| Cyhalothrin | 0.9998 | 0.01-2 | 0.002 | 0.005 | 0.05 | ||
| Permethrin | 0.9989 | 0.01-2 | 0.005 | 0.01 | 0.05 | ||
| Cypermethrin | 0.9999 | 0.01-2 | 0.01 | 0.03 | 0.05 | ||
| Etofenprox | 0.9999 | 0.01-2 | 0.005 | 0.01 | - | ||
| Fenvalerate | 0.9996 | 0.01-2 | 0.005 | 0.01 | 0.01 | ||
| Deltamethrin | 0.9994 | 0.01-2 | 0.01 | 0.04 | 0.05 |
y: peak area; x: mass concentration, mg/L; -: not given.
绿茶中各目标农药在3个加标水平下的平均回收率和相对标准偏差(n=6)
| Compound | LOQ* | 2LOQ | 10LOQ | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Recovery/% | RSD/% | Recovery/% | RSD/% | Recovery/% | RSD/% | ||||||
| Cyfluthrin | 108.5 | 1.72 | 106.9 | 5.63 | 106.4 | 2.32 | |||||
| Flucythrinate | 107.0 | 0.76 | 101.5 | 0.80 | 102.3 | 7.10 | |||||
| Fenpropathrin | 98.5 | 9.80 | 108.7 | 5.11 | 109.2 | 1.09 | |||||
| Bifenthrin | 102.0 | 2.53 | 100.7 | 6.30 | 100.3 | 6.66 | |||||
| Cyhalothrin | 97.5 | 1.14 | 109.2 | 1.25 | 105.2 | 4.23 | |||||
| Permethrin | 106.0 | 6.85 | 102.3 | 3.10 | 106.4 | 9.77 | |||||
| Cypermethrin | 107.0 | 8.80 | 99.5 | 3.04 | 102.3 | 6.29 | |||||
| Etofenprox | 104.7 | 6.82 | 107.3 | 8.07 | 100.8 | 4.21 | |||||
| Fenvalerate | 102.6 | 0.12 | 109.7 | 6.21 | 109.3 | 3.69 | |||||
| Deltamethrin | 105.8 | 6.03 | 106.4 | 6.73 | 91.4 | 5.54 | |||||
* The LOQ for deltamethrin is 0.04 mg/kg, the LOQ for cyfluthrin and cypermethrin is 0.03 mg/kg, the LOQ for flucythrinate, permethrin, etofenprox and fenvalerate is 0.01 mg/kg, and the LOQ for the remaining three compounds is 0.005 mg/kg.