Gas-Liquid Chromatographic Determination of Chlorpyriphos in Dursban Insecticide Formulations

1973 ◽  
Vol 56 (5) ◽  
pp. 1093-1095
Author(s):  
Alan R Hanks ◽  
Barbara S Engdahl ◽  
Billy M Colvin
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Good Precision ◽  
Total Chloride ◽  
Flame Ionization ◽  
Sample Extract ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic

Abstract A simple and rapid gas-liquid chromatographic method, using flame ionization detection and a column packed with OV-17/QF-1 on Gas-Chrom Q, is described. Chlorpyriphos is extracted from the formulation with chloroform, and dieldrin is added as an internal standard. The sample extract is injected into a gas chromatograph, and peak height ratios are used for quantitative measurement. Applicacation of the method to commercial samples gives good precision. The gas chromatographic procedure is far superior to the total chloride method for the determination of chlorpyriphos and yields values in close agreement to those obtained by infrared and colorimetric methods.

Gas-Liquid Chromatographic Determination of Strychnine in Grain Baits

1975 ◽  
Vol 58 (5) ◽  
pp. 961-964 ◽  
Author(s):  
Alan R Hanks ◽  
Barbara S Engdahl ◽  
Billy M Colvin
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Good Precision ◽  
Flame Ionization ◽  
Glass Column ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple and rapid gas-liquid chromatographic procedure, using a 6’ × ¼“ glass column packed with 5% SE-30 on Chromosorb W (DMCS) and a flame ionization detector, is described. Grain baits containing strychnine alkaloid are ground, mixed, and extracted by shaking with chloroform containing an internal standard, 1,3,5-triphenylbenzene. Without further cleanup, extract nitrates are injected directly into a gas chromatograph. Peak height ratios are used for quantitation of strychnine. The analysis of commercial samples shows that the method compares well with a commonly employed ultraviolet spectrophotometric method; good precision, with recoveries ranging from 89.9 to 91.7%, is obtained in the analysis of prepared samples. The method is sensitive to 2 μg strychnine.

Gas-Liquid Chromatographic Determination of Phenothiazine in Medicated Feeds

1973 ◽  
Vol 56 (1) ◽  
pp. 174-176
Author(s):  
Billy M Colvin ◽  
Albert E Prudom ◽  
Larry L Whitlock ◽  
Alan R Hanks
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Good Precision ◽  
Gas Chromatograph ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Medicated Feeds

Abstract A simple and rapid method is described for the determination of phenothiazine in feeds. Phenothiazine is extracted with chloroform containing chlorobenzilate as an internal standard. The extract is injected into a gas chromatograph and peak height ratios are used for quantitation. The analysis of commercial samples shows that the method compares well with the more commonly employed colorimetric AOAC method, and good precision, with recoveries ranging from 96.0 to 99.9%, is obtained in the analysis of prepared samples.

Gas-Liquid Chromatographic Determination of Erbon in Herbicide Formulations

1973 ◽  
Vol 56 (5) ◽  
pp. 1087-1090
Author(s):  
Alan R Hanks ◽  
Barbara S Engdahl ◽  
Billy M Colvin
Keyword(s):  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Test Material ◽  
Chromatographic Technique ◽  
Total Chloride ◽  
Flame Ionization ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Related Compounds

Abstract A simple and rapid gas-liquid chromatographic method, using flame ionization detection and a column packed with 5% silicone UCW 98 on Chromosorb W (HP), is described. Herbicide formulations containing Erbon are dissolved in chloroform, and Kepone is added as an internal standard. The sample solutions are injected directly into a gas chromatograph, and peak height ratios are used for quantitation. Using commercial herbicide formulations as test material, this procedure compares well with the more commonly employed titrimetric and total chloride procedures. As presented, this gas chromatographic technique has not been extended to include an estimation of the related compounds in technical Erbon. However, quantitation of these related compounds by this procedure is not precluded. This procedure does provide a method for more directly determining the compound of primary interest in Erbon formulations.

Improved liquid-chromatographic determination of mexiletine, an antiarrhythmic drug, in plasma.

1984 ◽  
Vol 30 (2) ◽  
pp. 319-322 ◽  
Author(s):  
W Mastropaolo ◽  
D R Holmes ◽  
M J Osborn ◽  
J Rooke ◽  
T P Moyer
Keyword(s):  
Methylene Chloride ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Reversed Phase ◽  
Internal Standard Peak ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic

Abstract In this improved reversed-phase liquid-chromatographic procedure for determination of mexiletine in plasma, mexiletine and an internal standard, chlorodisopyramide, are extracted with methylene chloride from 0.5 mL of serum or plasma; the extract is then concentrated and injected onto a C18 chromatographic column. Mexiletine in the column effluent is detected by monitoring absorbance at 210 nm. It is quantified by use of mexiletine-internal standard peak-height ratios. The relation between this ratio and mexiletine concentration is linear from 0.1 to 5.0 mg/L. The lower limit of detection is about 50 micrograms/L. At a mexiletine concentration of 2.0 mg/L in serum, intrarun precision (CV) is 2.9% and inter-run precision is 5.9%; at 0.5 mg/L, these CVs are 5.7% and 9.6%, respectively. Analytical recovery of added mexiletine in serum is 68-88%. Therapeutic concentrations of some commonly administered drugs in patients' specimens did not interfere. In serum from 38 patients receiving mexiletine for cardiac arrhythmia, concentrations measured by this method correlated with therapeutic efficacy.

Gas-Liquid Chromatographic Determination of Disulfoton in Formulations: Collaborative Study

1980 ◽  
Vol 63 (4) ◽  
pp. 869-872
Author(s):  
Thomas L Jensen ◽  
◽  
J B Audino ◽  
R Bishop ◽  
L Chenery ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Flame Ionization ◽  
Average Coefficient ◽  
Liquid Chromatographic Determination ◽  
Gasliquid Chromatography ◽  
Liquid Chromatographic

Abstract A rapid method is described for the determination of disulfoton (0,0-diethyl S-[2-(ethylthio)-ethyl] phosphorodithioate) in formulations by gasliquid chromatography (GLC). Samples are dissolved in acetone, and, after an internal standard is added, the samples are diluted to volume with solvent. They are then injected into a gas chromatograph equipped with a flame ionization detector and quantitated by peak height or area measurements. Fourteen collaborators made duplicate determinations on 4 samples including the technical product, a liquid, and 2 granular formulations. The average coefficient of variation was 0.847% for the liquid samples and 1.90% for the granules. The method has been adopted as official first action.

Gas-Liquid Chromatographic Determination of Tetradif on Technical and Formulations: Collaborative Study

1981 ◽  
Vol 64 (4) ◽  
pp. 829-832
Author(s):  
Bram Van Rossum ◽  
Albertus Martijn ◽  
James E Launer ◽  
◽  
E C Calamita ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract The gas-liquid chromatographic determination of tetradifon technical and formulations was collaboratively studied in duplicate with 12 laboratories. Six samples were dissolved in dichloroethane with n-hexacosane as the internal standard, chromatographed on a column of 3% SE-52, and detected by flame ionization. The average coefficients of variation were 1.2% for the 2 technical samples, 1.6% for the 2 wettable powders, and 1.5% for the 2 emulsifiable concentrates. The method has been adopted official first action.

Gas-Liquid Chromatographic Determination of Pyridazinones in Technical Products and Formulations

1978 ◽  
Vol 61 (1) ◽  
pp. 161-163
Author(s):  
Giuseppe Cellerino ◽  
Mariarosa Re
Keyword(s):  
Internal Standard ◽  
Standard Technique ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Flame Ionization ◽  
Selective Detector ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Technical Products

Abstract Simultaneous determination of the active ingredient and of by-products in technical and formulated pyridazinones was rapidly performed by gas-liquid chromatography with complete resolution of all compounds. Quantitative determination by the internal standard technique is accurate and precise. The lower limit of detectability is 8 × 10–12 g/sec with a flame ionization detector and 1 × 10–12 g/sec with a nitrogen-phosphorus selective detector operating in the nitrogen mode.

Reverse Phase High Performance Liquid Chromatographic Determination of Phenprocoumon in Tablets

1982 ◽  
Vol 65 (3) ◽  
pp. 753-756
Author(s):  
Walter F Schmidt
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reverse Phase ◽  
Assay Procedure ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high performance liquid chromatographic procedure has been developed for the assay of phenprocoumon in tablets. In comparison to the present official USP assay procedure, it is equivalent in precision and accuracy and is faster and more specific. A mobile phase consisting of a 1% solution of acetic acid in acetonitrile-water (4 + 3) separates phenprocoumon from warfarin internal standard on a 6 μm octadecylsilane (ODS) column with UV detection at 311 nm. The method enables the concurrent determination of phenprocoumon and possible contaminants such as salicylic acid.

Gas-Liquid Chromatographic Determination of Oxydemeton-Methyl in Commercial Formulations

1978 ◽  
Vol 61 (3) ◽  
pp. 500-503
Author(s):  
Leonard R Schronk ◽  
Billy M Colvin ◽  
Alan R Hanks
Keyword(s):  
Rapid Determination ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Detector Response ◽  
Gel Chromatography ◽  
Gas Liquid Chromatography ◽  
Flame Ionization ◽  
Silica Gel Chromatography

Abstract Flame ionization gas-liquid chromatography (GLC) with a 10% DC-200 on 80-100 mesh Gas-Chrom Q column is used for the rapid determination of oxydemeton-methyl in commercial formulations. The detector response is linear for 1.0–10.0 μg oxydemeton-methyl, with a sensitivity of 4 ng. The column was stabilized before analysis by injection of a lecithin solution. Samples were diluted with chloroform and injected; peak height ratios were used for quantitation with fluoranthrene as the internal standard. Carbaryl was removed from mixed formulations by silica gel chromatography, oxydemeton- methyl was eluted with methanolchloroform (2+98), and the eluate was collected for infrared (IR) and GLC analyses. Methoxychlor and Karathane were removed by chromatography on Florisil before IR analysis. GLC results compare favorably with those for IR, with recoveries ranging from 98.44 to 102.88% for spiked formulations.

Gas-chromatographic determination of mephenytoin and desmethylmephenytoin, after off-column alkylation.

1979 ◽  
Vol 25 (1) ◽  
pp. 172-175
Author(s):  
V A Raisys ◽  
A M Zebelman ◽  
S F MacMillan
Keyword(s):  
Active Metabolite ◽  
Chromatographic Method ◽  
Seizure Control ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Therapeutic Concentration ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a gas-liquid chromatographic method for determining mephenytoin and its active metabolite, desmethylmephenytoin, in human serum. 5-Methyl-5-phenylhydantoin is used as the internal standard. The method involves extraction of the drugs by adsorption onto charcoal and off-column derivatization to their pentyl derivatives. Peak height and concentration are linearly related and the day-to-day CV for therapeutic concentration is about 2 to 6%. No interferences by endogenous compounds or drugs commonly used for seizure control have been encountered.

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