Liquid Chromatography of Liquid Formulations Containing 2,4-Dichlorophenoxyacetic Acid, Dicamba, and 2-(2-Methyl-4-chlorophenoxy)propionic Acid as Their Salts

1983 ◽  
Vol 66 (5) ◽  
pp. 1220-1225 ◽  
Author(s):  
Robert B Grorud ◽  
John E Forrette
Keyword(s):  
Propionic Acid ◽  
Internal Standard ◽  
Solvent System ◽  
Dichlorophenoxyacetic Acid ◽  
Binary Solvent ◽  
Internal Standards ◽  
Liquid Chromatographic Method ◽  
Standard Solution ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic method has been developed for liquid herbicide combinations that contain different combinations of 3 active ingredients including 2,4-dichlorophenoxyacetic acid (2,4-D), 2-(2-methyl-4-chlorophenoxy)propionic acid (MCPP), and dicamba. A reverse phase column in the ion suppression mode and a binary solvent system separate all 3 herbicides quantitatively on a single chromatogram. The internal standard solution may contain 2 internal standards, salicylic acid and butyrophenone, for use with certain combinations of the herbicides. The solvent system resolves the compounds of interest from all significant impurities.

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.

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

1977 ◽  
Vol 60 (4) ◽  
pp. 868-872
Author(s):  
Norman E Skelly ◽  
Timothy S Stevens ◽  
David A Mapes
Keyword(s):  
High Pressure ◽  
Internal Standard ◽  
Dichlorophenoxyacetic Acid ◽  
Precision Data ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Liquid Chromatographic ◽  
Better Than

Abstract An automated high pressure liquid chromatographic method is described for the assay of 2,4-dichlorophenoxyacetic acid (2,4-D) in either salt or ester herbicide formulations. The method is specific for the 2,4-D isomer, and resolves all known impurities from 2,4-D and the internal standard. Ester products are assayed similarly to salt formulations, following room temperature in situ saponification. Results are thus obtained for all products as a per cent 2,4-D acid equivalent. Compounds are separated on a reverse phase microparticulate column with acetonitrile-water (20+80), buffered at pH 3. Precision data indicate a relative standard deviation of better than 1%. The method was developed to replace the nonspecific total chlorine, titration, and saponification assay procedures.

A sensitive liquid-chromatographic method for determination of 3'-azido-3'-deoxythymidine (AZT) in plasma and urine.

1988 ◽  
Vol 34 (8) ◽  
pp. 1565-1568 ◽  
Author(s):  
M A Hedaya ◽  
R J Sawchuk
Keyword(s):  
Human Plasma ◽  
Prescription Drugs ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Infectious Complications ◽  
Over The Counter ◽  
Internal Standards ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a liquid-chromatographic assay for AZT in human plasma and urine. This assay involves the use of two internal standards, allowing reference of AZT peaks to the appropriate internal standard, the choice depending on the range of concentrations encountered. This method is isocratic, specific, sensitive enough to allow quantification of AZT in concentrations observed clinically, and requires only 13 min of chromatographic time. We saw no interference from various over-the-counter and prescription drugs often used in treating the infectious complications of AIDS.

Liquid Chromatography of Liquid Formulations Containing 2,4-D, Dicamba, and MCPP as Their Salts: Collaborative Study

1984 ◽  
Vol 67 (4) ◽  
pp. 837-839
Author(s):  
Robert B Grorud ◽  
John E Forrette ◽  
◽  
J Bajovich ◽  
R L Bath ◽  
...  
Keyword(s):  
Liquid Mixture ◽  
Collaborative Study ◽  
Solvent System ◽  
Binary Solvent ◽  
Good Precision ◽  
Reverse Phase ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Binary Formulation ◽  
Technical Products

Abstract A liquid chromatographic method for any liquid mixture of the 3 herbicides 2,4-D, MCPP, and dicamba, found in commercial formulations, has been collaboratively studied. Each collaborator received 4 samples, 3 of which were ternary formulations and one a binary formulation of amine salts. Concentrations in the formulations range from 0.02 to 2.32% for dicamba, 0.32 to 21.7% for 2,4-D, and 0.22 to 11.6% for MCPP. A binary solvent system and the use of a specified 25 cm column of RP 10 μm in the reverse phase ion suppression mode will selectively quantitate each herbicide, separating many impurities found in the technical products. Standard deviations in each of 11 columns of results obtained indicate good precision. The method has been adopted official first action.

Collaborative Study of Gas-Liquid Chromatographic Method for Determining Methyl Parathion

1977 ◽  
Vol 60 (3) ◽  
pp. 720-723 ◽  
Author(s):  
Edwin R Jackson
Keyword(s):  
Methyl Parathion ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Technical Material ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract Methyl parathion in technical material, 4 lb/gal. emulsifiable concentrate, and 25% wettable powder was chromatographed on a 1.5% SE-30 + 1.5% OV-210 column with p,p′-DDE as internal standard and flame ionization detection. Three matched sample pairs were analyzed by 15 collaborators using peak height measurements. Liquids were diluted to volume with p,p′-DDE internal standard solution; wettable powders were extracted with chloroform-acetone (9+1), solvent was removed, and extracts were dissolved in internal standard solution. The mean of the coefficients of variation for the 6 samples was 1.65%. The method has been adopted as official first action.

Gas-Liquid Chromatographic Determination of Pentachloronitrobenzene in Pesticide Formulations

1976 ◽  
Vol 59 (3) ◽  
pp. 708-710
Author(s):  
Alan R Hanks ◽  
Christine W Cramer
Keyword(s):  
Chromatographic Method ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Liquid Chromatographic Method ◽  
Pesticide Formulations ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method has been developed to determine pentachloronitrobenzene (PCNB) in pesticide formulations including dusts, powders, granules, liquids, and fertilizers. Captan, disulfoton, and Terrazole do not interfere. Samples are extracted with chloroform, and an aliquot is mixed with an equal volume of internal standard solution containing o-terphenyl. PCNB is chromatographed on a 5% SE-30 column and quantitated by peak height ratios. The method has been subjected to a ruggedness test which indicates little sensitivity to changes in extraction and chromatographic conditions.

Collaborative Study of the High-Pressure Liquid Chromatographic Analysis of Picloram-2,4-D Formulations

1976 ◽  
Vol 59 (4) ◽  
pp. 748-752
Author(s):  
Norman E Skelly ◽  
Robert J Russell ◽  
Deborah F Porter
Keyword(s):  
High Pressure ◽  
Collaborative Study ◽  
Sodium Perchlorate ◽  
Internal Standard ◽  
Dichlorophenoxyacetic Acid ◽  
High Pressure Liquid Chromatographic ◽  
Coefficients Of Variation ◽  
Strong Anion Exchange ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Liquid Chromatographic

Abstract A high-pressure liquid chromatographic method for the analysis of picloram-2,4-D formulations has been studied by 11 collaborators. The method requires no sample preparation other than weighing and dilution. Salicylic acid is used as the internal standard. The compounds are separated on DuPont Zipax SAX (strong anion exchange resin) with 0.01M sodium tetraborate and 0.002M sodium perchlorate as the mobile phase, and measured by ultraviolet spectroscopy at 280 nm. Coefficients of variation for the 6 samples studied ranged from 1.35 to 3.54% for picloram (4-amino-3,5,6-trichloropicolinic acid) and 0.83 to 2.30% for 2,4-D (2,4-dichlorophenoxyacetic acid). Comments from the collaborators were generally favorable. The method has been adopted as official first action for the determination of both picloram and 2,4-D in picloram-2,4-D formulations.

Concurrent measurement of flecainide acetate and propranolol by normal-phase high-performance liquid chromatography.

1989 ◽  
Vol 35 (5) ◽  
pp. 857-860 ◽  
Author(s):  
C L Rognerud ◽  
C N Ou
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Normal Phase ◽  
Organic Layer ◽  
Chromatographic System ◽  
Liquid Chromatographic Method ◽  
Flecainide Acetate ◽  
Phase Liquid ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract This simple, isocratic, normal-phase liquid-chromatographic method concurrently measures flecainide acetate and propranolol in 100 microL of serum within 8 min. The chromatographic system consists of a Waters "Resolve" column packed with 5-microns silica spheres and a mobile phase of ammonium sulfate (10 mmol/L, pH 6.8)/methanol (22/78 by vol), pumped at 0.9 mL/min and monitored by a fluorometer (excitation at 225 nm and emission at 340 nm). After 100 microL of serum is mixed with 200 microL of the internal standard solution [N-(2-piperidylmethyl)-2,3-bis(2,2,2-trifluoroethoxy)-benzamide HCl, 2500 micrograms/L] and 200 microL of 0.2 mol/L sodium carbonate, the sample is extracted into butanol/hexane (20/80 by vol). The organic layer is separated and evaporated, and the residue is redissolved in 200 microL of methanol; 50 microL of this is injected onto the column. Relative recovery was 100% over the assay range of 25-2000 micrograms/L for flecainide and 10-2000 micrograms/L for propranolol. Within-run CVs were less than 2% for flecainide and less than 5% for propranolol; day-to-day CVs ranged from 5.0% to 6.5% for flecainide and from 3% to 12% for propranolol.

Assay of Formulations Containing 2,4-D and/or Picloram by Direct Injection High Pressure Liquid Chromatography

1979 ◽  
Vol 62 (2) ◽  
pp. 297-303
Author(s):  
Timothy S Stevens
Keyword(s):  
High Pressure ◽  
Chromatographic Method ◽  
Direct Injection ◽  
Hplc Method ◽  
Dichlorophenoxyacetic Acid ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Liquid Chromatographic

Abstract A rapid and precise fully automated, direct injection high pressure liquid chromatographic method is described for assaying liquid formulations of 2,4-dichlorophenoxyacetic acid (2,4-D) and/or picloram (4-amino-3,5,6-trichloropicolinic acid). The method is specific for the 2,4-D and picloram isomers. No sample preparation is needed, triplicate assays can be performed in 1 hr, and precision is about 1% relative at the 95% confidence level. Compounds are separated on a 9 mm id reverse phase microparticulate column with an eluant of ace* tonitrile-water (1+4) , buffered at pH 2.95. No bias was observed between this method and the official final action HPLC method for picloram and 2,4-D in picloram-2,4-D mixtures, 6.B09-6.B12.

High Pressure Liquid Chromatographic Analysis of Chlorpyrifos Containing Insecticidal Formulations: Collaborative Study

1981 ◽  
Vol 64 (3) ◽  
pp. 628-634 ◽  
Author(s):  
Norman E Skelly ◽  
David J Jackson ◽  
Phyllis K Anderson ◽  
◽  
J B Audino ◽  
...  
Keyword(s):  
High Pressure ◽  
Chromatographic Analysis ◽  
Collaborative Study ◽  
Internal Standard ◽  
High Pressure Liquid Chromatographic ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Analysis ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic method for determining chlorpyrifos was collaboratively studied. Three liquid and 2 solid formulations were analyzed by 12 collaborators. Samples were weighed and diluted with acetonitrile containing the internal standard, 1,4-dibromonaphthalene. Chlorpyriphos is separated on a Zorbax ODS column with acetonitrile- water-acetic acid (82 ± 17.5 ± 0.5) at 2 mL/min and monitored at 300 nm. Clay samples are extracted with the internal standard solution by agitation for 5 min. Coefficients of variation ranged from 1.28 to 2.40%. Results of all 12 collaborators fell within the 5% two-tail limits. The method has been adopted official first action.

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