Gas chromatographic determination of 2,4-dichlorophenoxyacetic acid (2,4-D) by mass fragmentography with a deuterated internal standard

1976 ◽  
Vol 24 (3) ◽  
pp. 635-637 ◽  
Author(s):  
Carlos H. Van Peteghem ◽  
Aubin M. Heyndrickx
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Dichlorophenoxyacetic Acid ◽  
Mass Fragmentography ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Deuterated Internal Standard

scholarly journals Optimization of the Conditions for Determining 2,4-D and Deltamethrin by HPLC

2020 ◽  
Vol 20 (4) ◽  
pp. 372-377
Author(s):  
Elena V. Melikhova ◽  
◽  
Olga V. Farafonova ◽  
Keyword(s):  
River Water ◽  
Chromatographic Determination ◽  
Capillary Columns ◽  
Dichlorophenoxyacetic Acid ◽  
Separate Determination ◽  
Isocratic Elution ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Gradient Mode

The paper presents the results of optimizing the conditions for the chromatographic determination of 2,4-dichlorophenoxyacetic acid and deltamethrin for two capillary columns (Supelcosil LC-18, Kromasil C-18). The modes of individual chromatography of pesticides were selected. The use of the isocratic elution mode in the joint presence of 2,4-dichlorophenoxyacetic acid and deltamethrin was shown and experimentally proved to be invalid. Three options were proposed for the conditions of the gradient mode of the separate detection of analytes in a mixture. The developed technique for the chromatographic separate determination of 2,4-D and deltamethrin with their joint presence was tested via analysis of river water and potato samples.

Determination of Multiresidues of Three Acid Herbicides in Tobacco by Liquid Chromatography/Tandem Mass Spectrometry

2015 ◽  
Vol 98 (2) ◽  
pp. 472-476 ◽  
Author(s):  
Shanshan Liu ◽  
Zhaoyang Bian ◽  
Fei Yang ◽  
Zhonghao Li ◽  
Ziyan Fan ◽  
...  
Keyword(s):  
Free Acid ◽  
Internal Standard ◽  
Dichlorophenoxyacetic Acid ◽  
Internal Standard Method ◽  
Liquid Chromatography Tandem Mass ◽  
Dispersive Spe ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Acid Herbicides ◽  
Methoxybenzoic Acid

Abstract A method to determine residues of the three acid herbicides, 2,4,5-trichlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid, and 3,6-dichloro-2-methoxybenzoic acid (dicamba), in tobacco using LC/MS/MS is presented. Because these herbicide residues in tobacco might exist in different forms (free acid, salt, and ester), tobacco samples were first pretreated by alkaline hydrolysis and then the pH was adjusted in order to convert the residues completely to their free acid forms. Dichloromethane extraction and dispersive SPE using C18 sorbent were carried out before LC/MS/MS analysis, and quantification was performed using the internal standard method. Linearity was good for all analytes (R2 ≥ 0.999) in the concentration range of 0.02 to 0.5 mg/kg. LODs were below 0.05 mg/kg. Recoveries ranged from 80.4 to 93.5%, and RSD was below 10%. This simple, efficient, and sensitive method can be applied to the determination of residues of the three acid herbicides in tobacco.

Determination of N-Nitrosodimethylamine Levels in Some Canadian 2,4-D Amine Formulations

1987 ◽  
Vol 70 (1) ◽  
pp. 49-51
Author(s):  
Ralph W Hindle ◽  
J Fred Armstrong ◽  
Adeline A Peake
Keyword(s):  
Thermal Energy ◽  
Internal Standard ◽  
Packing Material ◽  
Dichlorophenoxyacetic Acid ◽  
Energy Analyzer ◽  
Gas Chromatograph ◽  
Canadian Market ◽  
Sample Aliquot ◽  
2,4 Dichlorophenoxyacetic Acid

Abstract Levels of/V-nitrosodimethylamine (NDMA) were determined in 112 samples of 2,4-dichlorophenoxyacetic acid, (2,4-D), formulated as the dimethylamine salt, collected over a 2 year period from products on the Canadian market. A sample aliquot is partitioned with dichloromethane, and the co-extracted dimethylamine is removed by cleanup on a silica gel column. The eluates containing NDMA are concentrated, an internal standard of /V-nitrosodipropylamine is added, and nitrosamine levels are determined using a gas chromatograph interfaced with a thermal energy analyzer. Recoveries of NDMA and N-nitrosodiethylamine spiked into samples were 103 ± 16 and 96.3 ± 9.8%, respectively. Of the 112 samples analyzed, 92 were below 1 part per million (ppm) relative to the amount of 2,4-D in the samples, 16 were between 1 and 5 ppm, and 4 were greater than 5 ppm. The gas chromatographic column used is compared to a conventional packing material for volatile nitrosamine analysis. Formation of NDMA during cleanup and analysis was shown not to occur.

scholarly journals Electroanalytical Methodology for the Direct Determination of 2,4-Dichlorophenoxyacetic Acid in Soil Samples Using a Graphite-Polyurethane Electrode

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fernanda Ramos de Andrade ◽  
Renata Alves de Toledo ◽  
Carlos Manoel Pedro Vaz
Keyword(s):  
Irreversible Process ◽  
Direct Determination ◽  
Parameters Optimization ◽  
Dichlorophenoxyacetic Acid ◽  
Reduction Peak ◽  
Undisturbed Soil ◽  
Polyurethane Composite ◽  
Experimental Parameters ◽  
2,4 Dichlorophenoxyacetic Acid

An electroanalytical methodology was developed for the direct determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) using a graphite-polyurethane composite electrode and square wave voltammetry (SWV). 2,4-D exhibited one reduction peak with characteristics of an irreversible process at −0.54 V (versus Ag/AgCl), which is controlled by the diffusion of the reagent on the electrode surface. After the experimental parameters optimization (pH 2.0,f=50 s−1,a=0.50 V, andΔEi=0.03 V), analytical curves were constructed in the range of 0.66 mg L−1to 2.62  mg L−1. Detection (LD) and quantification (LQ) limits were 17.6 μg L−1and 58.6 μg L−1, respectively. The methodology was successfully applied to measure the percolation of the herbicide 2,4-D in undisturbed soil columns of different granulometric compositions.

Amplifying Bienzyme Cycle-linked Immunoassays for Determination of 2,4-Dichlorophenoxyacetic Acid

1996 ◽  
Vol 799 (1 Enzyme Engine) ◽  
pp. 519-524 ◽  
Author(s):  
FRANK F. BIER ◽  
EVA EHRENTREICH-FÕRSTER ◽  
FRIEDER W. SCHELLER
Keyword(s):  
Dichlorophenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid

Isomer Specific Assay of Ester and Salt Formulations of 2,4-Dichlorophenoxyacetic Acid by High Pressure Liquid Chromatography: Collaborative Study

1978 ◽  
Vol 61 (5) ◽  
pp. 1163-1165 ◽  
Author(s):  
Timothy S Stevens ◽  
Norman E Skelly ◽  
Robert B Grorud
Keyword(s):  
High Pressure ◽  
Collaborative Study ◽  
Internal Standard ◽  
Dichlorophenoxyacetic Acid ◽  
High Pressure Liquid Chromatographic ◽  
Coefficients Of Variation ◽  
Standard Solution ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) assay of ester and salt formulations of 2,4-D has been collaboratively studied. The method is specific for 2,4-D isomer and resolves all known impurities from 2,4-D and the internal standard p-bromophenol. In situ saponification, at room temperature, is performed by adding a combined saponification-internal standard solution to ester products. The same saponification- internal standard solution is added to amine salts and the analytical standard. The injected aqueous potassium salt solution of 2,4-D is then converted to the acid form by an acidic buffered mobile solvent of 20% acetonitrile in water. Optimum chromatography is attained by a mobile solvent pH of 2.95 in a reverse phase microparticulate column, by ion suppression. Each of the 9 collaborators received 3 different ester and 2 different amine formulations of 2,4-D. The coefficients of variation of 2,4-D acid equivalent ranged from 1.22 to 1.59%. The method has been adopted as official first action.

High-Performance Liquid Chromatographic Determination of Memantine in Human Urine Following Solid-Phase Extraction and Precolumn Derivatization

2013 ◽  
Vol 96 (6) ◽  
pp. 1302-1307 ◽  
Author(s):  
Karim Michail ◽  
Hoda Daabees ◽  
Youssef Beltagy ◽  
Magdy Abd Elkhalek ◽  
Mona Khamis
Keyword(s):  
Human Urine ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Therapeutic Drug ◽  
Time Interval ◽  
Precolumn Derivatization ◽  
Uv Detector

Abstract A validated HPLC-UV method is presented for the quantification of urinary memantine hydrochloride, a novel medication approved to treat moderate and advanced cases of Alzheimer's disease. The drug and amantadine hydrochloride, the internal standard, were extracted from human urine using SPE. The extract was then buffered and derivatized at room temperature using o-phthalaldehyde in the presence of N-acetyl-L-cyteine. Chromatographic separation of the formed derivatives was achieved on a C18 column using methanol–water mobile phase adjusted to pH 7 and pumped isocratically at 1 mL/min. The UV detector was set at 340 nm. The chromatographic run time did not exceed 10 min. The LOD and LOQ were 8 and 20 ng/mL, respectively. The RSDs for intraday and interday precisions did not exceed 5.5%. The method was used to monitor memantine hydrochloride in human urine in order to determine an appropriate sampling interval for future noninvasive therapeutic drug monitoring. The assay could also be applied to the determination of amantadine. The described assay showed that a postdosing time interval of 25–75 h seems adequate for sampling and monitoring memantine in urine.

Sign in / Sign up

Export Citation Format

Share Document