scholarly journals Smartphone-based molecularly imprinted sensors for rapid detection of thiamethoxam residues and applications

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258508
Author(s):  
Sihua Peng ◽  
Aqiang Wang ◽  
Yuyang Lian ◽  
Xi Zhang ◽  
Bei Zeng ◽  
...  
Keyword(s):  
Pesticide Residues ◽  
Rapid Detection ◽  
Rapid Determination ◽  
Detection System ◽  
Residue Analysis ◽  
Differential Pulse ◽  
Detection Technology ◽  
Screen Printed Carbon Electrode ◽  
Relative Standard

In order to achieve rapid detection of thiamethoxam residues in mango, cowpea and water, this study modified the screen printed carbon electrode (SPCE) to make a specific molecular imprinting sensor (Thiamethoxam-MIP/Au/rGO/SPCE) for thiamethoxam. An integrated smartphone platform was also built for thiamethoxam residue analysis. The performance of the complete system was analyzed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The system was then applied for the rapid determination of thiamethoxam residues in water, mango and cowpea samples. The results showed that the molecular sensor showed good linearity in the range 0.5–3.0 μmol/L of thiamethoxam. The detection limit of thiamethoxam was 0.5 μmol/L. Moreover, the sensor had good reproducibility and anti-interference performance. The average recovery rates of the pesticide residues in water, mango and cowpea samples were in the range of 90–110% with relative standard deviations < 5%. The rapid detection system for thiamethoxam residue constructed in this study was simple, reliable, reproducible and had strong anti-interference. It has broad application prospects in the field detection of thiamethoxam residue, and serves as a valuable reference for the further development of rapid detection technology of pesticide residues in the field of environment and food safety.

Simultaneous determination of 118 pesticide residues in Chinese teas by gas chromatography-mass spectrometry

2009 ◽  
Vol 63 (1) ◽  
Author(s):  
Xin Yang ◽  
De Xu ◽  
Jian Qiu ◽  
Hua Zhang ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Pesticide Residues ◽  
Residue Analysis ◽  
Gel Permeation Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard

AbstractAn efficient and sensitive method for simultaneous determination of 118 pesticide residues in teas has been established and validated. A multi-residue analysis of pesticides in tea involved extraction with ethyl acetate-hexane, clean-up using gel permeation chromatography (GPC) and solidphase extraction (SPE), and subsequent identification and quantification of the selected pesticides by gas chromatography-mass spectrometry (GC-MS). For most of the target analytes, optimized pretreatment processes led to no significant interference with analysis of sample matrix, and the determination of 118 compounds was achieved in about 60 min. In the linear range of each pesticide, the correlation coefficient was R 2 ≥ 0.99. At the low, medium and high three fortification levels of 0.05–2.5 mg kg−1, 118 pesticides average recoveries range from 61 % to 121 % and relative standard deviations (RSD) were in the range of 0.6–9.2 % for all analytes. The limits of detection for the method were 0.00030-0.36 mg kg−1, depending on each pesticide.

scholarly journals Application of liquid chromatography with diode-array detector for determination of acetamiprid and 6-chloronicotinic acid residues in sweet cherry samples

2012 ◽  
Vol 27 (4) ◽  
pp. 321-329 ◽  
Author(s):  
Sanja Lazic ◽  
Dragana Sunjka ◽  
Nada Grahovac ◽  
Valéria Guzsvány ◽  
Ferenc Bagi ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Sweet Cherry ◽  
Rapid Determination ◽  
Residue Analysis ◽  
Array Detector ◽  
Diode Array ◽  
Diode Array Detector ◽  
Simple Method ◽  
Relative Standard

A rapid and simple method for simultaneous determination of acetamiprid and its metabolite 6-chloronicotinic acid in sweet cherry samples has been developed. This residue analysis method is based on the reversed phase separation on C18 column with gradient elution. Analytes? determination and quantification were performed by high performance liquid chromatography (HPLC) with diode-array detector and chromatograms were extracted at 230 nm. Extraction efficiency experiments demonstrated the ability of this method to extract neonicotinoids from sweet cherry samples. These insecticides were extracted with a mixture of acetonitril/0.1N ammonium-chloride (8/2, v/v). The average recoveries of acetamiprid and 6-chlornicotinic acid from sweet cherry samples were in the range of 95-101% and 73-83%, respectively, with the associated relative standard deviations (RSDs) <5%. Expanded measurement uncertainties for the analyzed compounds were 2.7 and 3.01%. The limit of quantification (LOQ) was 10 ?g/kg and 30 ?g/kg for acetamiprid and 6-chloronicotinic acid, respectively. Thus, the developed HPLC/DAD method can be considered a useful tool for sensitive and rapid determination of acetamiprid and 6-chloronicotinic acid. Hence, the method may find further application in the analysis of real sweet cherry samples contaminated with these insecticides at a ppb level.

scholarly journals Rapid Determination of Ethylene Oxide and 75 VOCs in Ambient Air with Canister Sampling and Associated Growth Issues

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 35
Author(s):  
Jason Hoisington ◽  
Jason S. Herrington
Keyword(s):  
Ethylene Oxide ◽  
Rapid Determination ◽  
Complex Mixture ◽  
Ambient Air ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Accuracy ◽  
Relative Standard ◽  
Wide Range ◽  
Us Epa

A canister-based sampling method along with preconcentrator-Gas chromatography-Mass Spectrometry (GC-MS) analysis was applied to ethylene oxide (EtO or EO) and 75 other volatile organic compounds (VOCs) in ambient air. Ambient air can contain a large variety of VOCs, and thorough analysis requires non-discriminatory sampling and a chromatographic method capable of resolving a complex mixture. Canister collection of whole air samples allows for the collection of a wide range of volatile compounds, while the simultaneous analysis of ethylene oxide and other VOCs allows for faster throughput than separate methods. The method presented is based on US EPA Method TO-15A and allows for the detection of EtO from 18 to 2500 pptv. The method has an average accuracy of 104% and precision of 13% relative standard deviation (RSD), with an instrument run time of 32 min. In addition, a link between canister cleanliness and ethylene oxide growth is observed, and potential mechanisms and cleaning strategies are addressed.

Residue Analysis of Organophosphorus and Organochlorine Pesticides in Fatty Matrices by Gas Chromatography Coupled with Electron-Capture Detection

2006 ◽  
Vol 61 (5-6) ◽  
pp. 341-346 ◽  
Author(s):  
Jae-Woo Park ◽  
A. M. Abd El-Aty ◽  
Myoung-Heon Lee ◽  
Sung-Ok Song ◽  
Jae-Han Shim
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Simple Procedure ◽  
Linear Regression Analysis ◽  
Residue Analysis ◽  
Electron Capture Detection ◽  
Relative Standard ◽  
Wide Range ◽  
Repeatability And Reproducibility

A multiresidue method for the simultaneous determination of 22 organochlorine (OCs) and organophosphorus (Ops) pesticides (including isomers and metabolites), representing a wide range of physicochemical properties, was developed in fatty matrices extracted from meat. Pesticides were extracted from samples with acetonitrile/n-hexane (v :v, 1:1). The analytical screening was performed by gas chromatography coupled with electron-capture detection (ECD). The identification of compounds was based on their retention time and on comparison of the primary and secondary ions. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of samples fortified at 38 to 300 ng/g levels. Correlation coefficients for the 22 extracted pesticide standard curves (linear regression analysis, n = 3) ranged from 0.998 to 1.000. Recovery studies from 2 g samples fortified at 3 levels demonstrated that the GC-ECD method provides 64.4-96.0% recovery for all pesticides except 2,4′-DDE (44.6-50.4%), 4,4′-DDE (51.1-57.5%) and 2,4′-DDT (50.0-51.2%). Both repeatability and reproducibility relative standard deviation values were < 20% for all residues. Detection limits ranged from 0.31 to 1.27 ng/g and quantification limits were between 1.04 and 4.25 ng/g. The proposed analytical method may be used as a simple procedure in routine determinations of OCs and Ops in meat. It can also be applied to the determination of pesticide multi-residues in other animal products such as butter and milk.

Determination of multiple organochlorine pesticide residues in shrimp using modified QuEChERS extraction and gas chromatography

2018 ◽  
Vol 16 (1) ◽  
pp. 81-93
Author(s):  
MDH Prodhan ◽  
SN Alam
Keyword(s):  
Gas Chromatography ◽  
Organochlorine Pesticide ◽  
Pesticide Residues ◽  
Limit Of Detection ◽  
Residue Analysis ◽  
Limit Of Quantification ◽  
Modified Quechers ◽  
Endosulfan Sulphate ◽  
Organochlorine Pesticide Residues

Determination of organochlorine pesticide residues in shrimp is very important to ensure the consumer’s safety and to fulfill the importer’s demand. Therefore, a simple and efficient multiple organochlorine pesticide residues analytical method using quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction technique and Gas Chromatography coupled with Electron Capture Detector (ECD) has been developed and validated for the determination of 19 organochlorine pesticides (α- BHC, δ- BHC, β- BHC, γ- BHC, Heptachlor, Aldrin, Heptachlor Epoxide, γ- Chlordane, α- Chlordane, α- Endosulfan, 4,4 DDE, Dieldrin, Endrin, 4,4 DDD, β- Endosulfan, 4,4 DDT, Endosulfan sulphate, Methoxychlor, and Endrin Ketone) in shrimp. The method was validated by evaluating the accuracy, precision, linearity, limit of detection (LOD) and limit of quantification (LOQ). The average recoveries of the selected pesticides ranged from 84% to 106% with RSDr ≤ 14% in four fortification levels of 0.05, 0.1, 0.2 and 0.3 mg kg-1. The linearity was ≥ 0.996 for all of the selected pesticides with matrix matched calibration standards. The LOD ranged from 0.003 to 0.009 mg kg-1 and the LOQ was 0.05 mg kg-1. This method was applied successfully for the residue analysis of 40 shrimp samples collected from different regions in Bangladesh.SAARC J. Agri., 16(1): 81-93 (2018)

Rapid determination of products of phenol hydrogenation in a supercritical water system using headspace gas chromatography

2015 ◽  
Vol 69 (5) ◽  
Author(s):  
Qing-Qing Guan ◽  
Xiao-Dian Huang ◽  
Yan-Hua Zeng ◽  
Chao-Hai Wei ◽  
Ping Ning ◽  
...  
Keyword(s):  
Supercritical Water ◽  
Rapid Determination ◽  
Reaction System ◽  
Headspace Analysis ◽  
Water System ◽  
Anhydrous Calcium Chloride ◽  
Crystal Water ◽  
Phenol Hydrogenation ◽  
Relative Standard

AbstractThis paper reports a headspace analysis technique for the determination of products, i.e., cyclohexanone (CE) and cyclohexanol (CL), of phenol hydrogenation in a supercritical water reaction system (SWRS) with water removal by hydrate formation. An addition of anhydrous calcium chloride leads to water absorption resulting in crystal water; thus, the samples can be quantitatively measured without the influence of water. After achieving equilibrium at 150­°C and maintaining it for 5 min, the obtained results showed a relative standard deviation of less than 5.3 % and the recovery ranged from 93 % to 104 %. The presented method is simple and accurate for the analysis of CL, CE and phenol in samples from phenol conversion in SWRS.

Rapid Determination of Sulfite by Flow Injection Analysis Based on Fuchsin′s Addition

2013 ◽  
Vol 295-298 ◽  
pp. 950-953 ◽  
Author(s):  
Dong Yuan ◽  
Da You Fu ◽  
Wen Yuan Tan
Keyword(s):  
Flow Injection ◽  
Addition Reaction ◽  
Rapid Determination ◽  
Sampling Rate ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Relative Standard ◽  
Replicate Measurements ◽  
Good Agreement

A rapid spectrophotometric method for flow injection determination of sulfite in tan wastewater is described. The proposed method was based on the addition reaction of sulfite with fuchsin in Na2B4O7-NaOH medium. The optimum conditions allow a linear calibration range of 0.01-1.20 μg ml-1 SO32-. The detection limit is 0.0023μg ml-1 (S/N=3), and the relative standard deviation for night replicate measurements is 1.1% for 0.5μg ml-1 of sulfite. The sampling rate is 60 samples h-1. The procedure has been applied to the determination of sulfite in tan wastewater. The results were in good agreement with those obtained by pararosaniline method.

Simultaneous Determination of Eight New Generation Amide Insecticide Residues in Complex Matrix Agri-food by Multi-walled Carbon Nanotube Cleanup and UPLC-MS/MS

2021 ◽  
Author(s):  
Tao Lin ◽  
Xinglian Chen ◽  
Li Wang ◽  
Haixian Fang ◽  
Maoxuan Li ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Simultaneous Determination ◽  
High Performance ◽  
Rapid Determination ◽  
Complex Matrix ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes

Abstract The simultaneous determination method of 8 amide pesticides by multi-walled carbon nanotubes (MWCNs) cleanup, combined with QuEChERS method and ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry has been developed and successfully applied in complex matrix such as green onions, celery, leeks, citrus, lychees, avocado. The matric effect of MWCNs is optimized and compared with QuEChERS materials. The results show that MWCNs can effectively reduce the matrix effect in sample extraction. The mass spectrometry is optimized, through their chemical structure skeletons, the ESI+ and ESI- mode are simultaneously scanned in the method. The coefficient (r) is greater than 0.9990, the limit of quantification ranges from 0.03 to 0.80 μg/kg, the recovery rate ranges from 71.2% to 120%, and the relative standard deviation (RSD) ranges from 3.8% to 9.4%. The method is fast, simple, sensitive, and has good purification effect. It is suitable for the rapid determination of amide pesticides in complex matrix agri-food.

Sign in / Sign up

Export Citation Format

Share Document